Synergistic Stabilization and Ecological Restoration in Multi-Metal Contaminated Soil: The Efficacy of Fe/Mn (Hydr)oxide-Phosphate Composites (FMPs) for Cd, Pb, Cu, Zn

Synergistic Stabilization and Ecological Restoration in Multi-Metal Contaminated Soil: The Efficacy of Fe/Mn (Hydr)oxide-Phosphate Composites (FMPs) for Cd, Pb, Cu, Zn | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Synergistic Stabilization and Ecological Restoration in Multi-Metal Contaminated Soil: The Efficacy of Fe/Mn (Hydr)oxide-Phosphate Composites (FMPs) for Cd, Pb, Cu, Zn Rui Xu, Yuchen Shi, Lang Liao, Zhe Yin, Qian Li, Guangfei Qu, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8576852/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 11 You are reading this latest preprint version Abstract Soil heavy metal pollution, especially multi-metal contamination, is a serious environmental challenge. Stabilization has become a practical method to reduce pollution while maintaining soil ecological functions. In this study, functional materials (FMPs) composed of Fe/Mn (hydro)oxides and phosphate minerals were prepared by optimizing the molar ratio of Fe(II), Fe(III), Mn(II), and PO 4 3− . Contaminated topsoil from a mining area was used to simulate real-world conditions. After 60 days of FMPs application at 5 wt.%, DTPA-extractable Cd, Pb, Cu, and Zn levels were reduced by 70.10%, 99.82%, 68.30% and 75.05%, respectively, meeting stabilization standards (HJ 1282–2023). Notably, FMPs promoted the conversion of Cd, Pb, Cu, and Zn from labile (F1/F2) to stable (F3/F4) fractions. Additionally, FMPs significantly increased soil pH, EC, TP, AP, and NH 4 + -N, while enhancing S_ACP, S_CL, and S_CAT activities, but lowered Eh, NO 3 − -N, AK, and S_UE activity. Microbial community analysis showed that FMPs changed soil microbial communities, decreasing bacterial diversity and richness (p < 0.05), but increasing fungal diversity and richness (p < 0.05). Molecular ecological networks indicated stronger bacterial connections and simpler fungal networks, with low-abundance taxa playing crucial ecological roles. These results underscore the effectiveness and environmental sustainability of FMPs for remediation of multi-metal contaminated soils. Heavy Metals Multi-Metal Contaminated Soil Simultaneous Stabilization Leaching Toxicity Ecological Effects Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 1. Introduction Heavy metal contamination in soil and aquatic ecosystems has emerged as a pressing global environmental issue, driven by anthropogenic activities such as mining, industrial discharges, and agricultural practices. Heavy metals, distinguished by their environmental persistence, bioaccumulative propensity, and intrinsic toxicity, exert profound perturbations on soil ecosystem architecture and functionality upon infiltrating terrestrial systems. Their synergistic interactions with heterogeneous soil matrices amplify ecological destabilization through microbial community dysbiosis, phytotoxic inhibition of plant physiology, and irreversible degradation of pedogenic properties, ultimately jeopardizing ecosystem resilience and agroecosystem productivity. The ecotoxicological cascade extends beyond soil compartments via trophic transfer mechanisms, facilitating heavy metal bioamplification through food chains and engendering chronic human exposure risks associated with carcinogenic, neurotoxic, and teratogenic pathologies. In particular, real contaminated sites often exhibit the co-occurrence of multiple heavy metal elements, which manifests more deleterious toxicological dynamics due to the synergistic toxicity multiplier effect [1–3]. Therefore, creating safe, innovative, and targeted green remediation methods that are effective and affordable has become a key research focus and a major challenge in managing contaminated soils under today’s environmental conditions. The environmental hazards associated with heavy metals primarily stem from their bioavailable fractions and their inherent lack of physiological necessity in biological systems. In contrast, the development of target-specific, synchronized multi-heavy metal remediation strategies that integrate high efficiency, economic viability, and ecological compatibility has emerged as a key scientific frontier in contemporary soil restoration research. As a paradigmatic chemoremediation strategy, in situ stabilization technologies for soil-bound heavy metals achieve contaminant immobilization through three synergistic mechanisms: (i) altering geochemical speciation via ligand-specific coordination, (ii) inducing mineral phase precipitation through pH/redox-driven crystallization, and (iii) facilitating surface complexation with reactive substrates. Collectively, these processes suppress contaminant mobility by reducing both leachable metal species and bioaccessible fractions, while preserving soil matrix integrity. Current remediation materials for heavy metal-contaminated soils predominantly include siliceous materials, calcium-based compounds, phosphorus-containing agents, organic amendments, clay minerals, metal oxides, biochar, novel nanomaterials, and composite formulations (i.e., multi-component stabilizer combinations) [4]. Critical analyses of domestic and international mechanisms and application efficacy reveal two principal limitations. First, single-component stabilizers offer limited active sites and poor selectivity, rendering them incapable of synchronously immobilizing multiple metals. Second, multi-component composites typically rely on simple physical blending rather than engineered synergistic interactions, leading to higher dosage requirements and increased operational costs. Consequently, the development of soil-specific, multifunctional materials capable of coordinated multi-metal stabilization has become a prominent research priority in the field of soil heavy metal remediation. Metal (hydro)oxides, such as those of Fe, Mn, and Al, are widely present in natural environments and have been extensively employed as remediation agents for heavy metal contamination due to their large specific surface areas, amphoteric properties, and exceptional heavy metal adsorption capacities. They immobilize heavy metals through mechanisms including specific adsorption, coprecipitation, and surface complexation, predominantly occurring at -OH groups on the material surface. These surface groups typically become negatively charged (deprotonated) at high pH (Eq. ( 1 )) and positively charged (protonated) at low pH (Eq. ( 2 )), with Eq. ( 3 ) illustrating the adsorption of divalent metal ions (Me 2+ ) onto the surface groups of metal (hydro)oxides. To date, an array of naturally occurring metal (hydro) oxides, such as ferrihydrite, birnessite, goethite, magnetite, lepidocrocite, cryptomelane, aragonite, diaspore, boehmite, gibbsite, hematite, hausmannite, and maghemite, have been shown to effectively immobilize heavy metal ions [5]. Previous studies have reported that metals, including Pb, Cd, Cu, Ni, Zn, As, Sb, and Cr, can undergo natural attenuation through precipitation with metal mineral phases [6]. Rajapaksha et al. [7] demonstrated that natural iron oxides and gibbsite can reduce the NH 4 OAc-extractable fractions of Pb and Cu in shooting range-contaminated soils. In a related study, Sun et al. [8] synthesized Fe–Mn oxide-modified biochar (FMBC), which significantly altered the composition and metabolic functions of soil bacterial communities. Notably, the relative abundances of certain phyla, such as Firmicutes, Ascomycota, and Actinobacteria, increased under FMBC treatment, thereby promoting soil heavy metal adsorption and bolstering soil ecosystem stability. Nevertheless, the practical application of both naturally occurring and synthetic metal (hydro)oxides in soil remediation is severely constrained by inherent drawbacks such as particle aggregation, poor compatibility, and insufficient selectivity toward heavy metals. In response, extensive research has focused on enhancing the immobilization efficiency of heavy metals in contaminated soils by increasing the active sites of metal (hydro)oxides or combining them with other stabilizing materials. $$\:\equiv\:\text{XO}{\text{H}}_{2}^{+}\to\:\equiv\:\text{XO}{\text{H}}^{0}\text{+}{\text{H}}^{+}$$ 1 $$\:\equiv\:\text{XO}{\text{H}}^{0}\to\:\equiv\:\text{X}{\text{O}}^{-}\text{+}{\text{H}}^{+}$$ 2 $$\:\equiv\:\text{XO}{\text{H}}^{0}\text{+M}{\text{e}}^{\text{2+}}\to\:\equiv\:\text{XOM}{\text{e}}^{+}\text{+}{\text{H}}^{+}$$ 3 Recent studies have identified phosphate groups as having exceptional cation exchange capacities, primarily attributed to the strong affinity between metal cations and phosphate ligands. This distinctive property facilitates the straightforward substitution of ions within the phosphate matrix without disrupting charge neutrality, thereby enabling effective interactions with divalent heavy metal ions (e.g. Pb²⁺, Cd²⁺, Zn²⁺, Cu²⁺) through the formation of highly insoluble metal-phosphate mineral complexes that ultimately achieve efficient metal ion stabilization [9, 10]. Mounting evidence further underscores the efficacy of phosphate-functionalized materials in soil remediation efforts. Notably, recent investigations into the synergistic application of phosphate-functionalized iron-based nanomaterials and phosphate-solubilizing bacteria (PSB) for lead-contaminated soil remediation revealed a dual mechanism: the nanomaterials mediated toxic Pb²⁺ reduction and precipitation while simultaneously bolstering microbial community structure, with PSB inoculation further promoting lead stabilization through biomineralization processes [11]. In addition, Song et al. [12] demonstrated that monocalcium phosphate application effectively immobilized Cu, Zn, and Cd contaminants in soil matrices while restoring bacterial community diversity in heavy metal-impacted ecosystems. Moreover, our previous work resulted in the development of Fe-Mn (hydr)oxide-phosphate composites (FMPs) through optimized molar ratios of Fe 2+ , Fe 3+ , Mn 2+ , and PO 4 3− . Comprehensive characterization revealed two predominant immobilization mechanisms in aqueous systems: 1) metal-phosphate precipitation via strong ligand complexation at surface phosphate groups, and 2) chemisorption through hydroxyl groups present on the FMPs surface. This dual mechanism afforded excellent immobilization efficiencies for Cd 2+ , Pb 2+ , Cu 2+ , and Zn 2+ in aqueous systems, highlighting the material’s promise as a multifunctional remediation agent for multi-metal contaminated environments [13]. However, no reports have yet examined the remediation efficacy or ecological restoration potential of FMPs in soils contaminated by multiple heavy metals. This paper presents a systematic investigation into the dose-dependent effects of remediation amendments (FMPs) on heavy metal(loid) bioavailability, leaching toxicity, and chemical speciation transformations in highly Cd-Pb-Cu-Zn co-contaminated soil. Through a multidimensional analysis, we comprehensively evaluated amendment-induced changes in soil physicochemical properties, enzymatic activity profiles, and microbial community structure–function relationships in multi-metal co-contaminated systems. Our integrated approach reveals the critical linkages between amendment dosage, metal immobilization efficiency, and soil ecological health restoration, providing mechanistic insights into the biogeochemical processes governing heavy metal stabilization and soil functionality recovery. 2. Materials and methods 2.1. Sample collection The high-concentration Cd-Pb-Cu-Zn co-contaminated soil was collected from the contaminated surface soil (0 ~ 20 cm) in the vicinity of the Shuikoushan lead-zinc mining area (26.32°N, 112.29°E) in Changning, Hunan Province, China. The collected soil samples were thoroughly homogenized, and plant residues and gravel were removed before further analysis. The concentrations of heavy metals in the soil are presented in Table S1 . 2.2. Preparation of FMPs According to our previous work [13], the FMPs material, characterized by a molar ratio of Fe 2 ⁺: Fe 3 ⁺: Mn 2 ⁺: PO 4 3 ⁻ of 1: 3: 3: 3, demonstrated exceptional performance in the liquid-phase adsorption of Cd(II), Pb(II), Cu(II), and Zn(II). Consequently, it was selected for the stabilization and remediation of Cd-Pb-Cu-Zn co-contaminated soil. Briefly, FeSO 4 ·7H 2 O, Fe 2 (SO 4 ) 3 ·xH 2 O, and MnSO 4 were dissolved in water at specific molar ratios, and silica was added to prepare a mixed metal solution. Subsequently, an NH 4 H 2 PO 4 solution was introduced into the mixed metal solution at a molar ratio of Fe 2 ⁺: Fe 3 ⁺: Mn 2 ⁺: PO 4 3 ⁻ of 1: 3: 3: 3 under continuous stirring. The pH of the solution was then adjusted using ammonia water, followed by further stirring, filtration, washing, drying, and grinding to obtain the FMPs material. The entire preparation process, except for drying, was conducted at room temperature. 2.3. Experimental design The soil stabilization experiments were established with four distinct treatment groups. Soil samples of each contamination type were sieved through a 1 mm mesh, and 1000 g aliquots were weighed into polyethylene containers. These samples were thoroughly mixed with predetermined amounts of FMPs. The application rates of the material were determined based on the soil's bioavailable heavy metal content and the material's immobilization efficiency, set at 0%, 1% (w/w), 3% (w/w), and 5% (w/w), respectively. Each treatment was replicated three times to ensure statistical robustness. Deionized water was added to maintain soil moisture at approximately 50%, and daily gravimetric measurements were conducted to monitor and replenish water loss, ensuring consistent environmental conditions across all treatments. The polyethylene containers were placed in a natural outdoor environment to closely simulate real-world conditions, while the bioavailable heavy metal content in the soil was periodically measured. After 60 days of remediation, the soil was divided into two portions: one portion was air-dried and sieved through a 100-mesh sieve, while the other portion was immediately frozen and stored at -80°C for subsequent analysis. To avoid ambiguity, the application rates of 1 wt.%, 3 wt.%, and 5 wt.% were designated as FMPs1, FMPs3, and FMPs5, respectively. All reagents used in this paper are analytically pure. 2.4. Analysis of soil physicochemical properties The speciation of Cd, Pb, Cu, and Zn in the soil was determined using the BCR sequential extraction method [14], with the specific experimental procedures and extraction reagents consistent with those described in the literature. By the Technical Specification for Remediation of Contaminated Soil by Solidification/Stabilization (HJ 1282 − 2023), the toxicity leaching concentrations of Cd, Pb, Cu, and Zn in the soil were measured using the Sulfuric Acid and Nitric Acid Method for Leaching Toxicity of Solid Waste (HJ/T 299 − 2007). The experimental steps and extraction reagents strictly adhered to the standard protocols. The bioavailable concentrations of Cd, Pb, Cu, and Zn were extracted using the DTPA method. After extraction, the solutions were filtered through a 0.45 µm membrane, and the heavy metal concentrations were quantified using inductively coupled plasma atomic emission spectrometry (ICP − AES). Soil pH and redox potential (Eh) were measured using a pH meter, while soil electrical conductivity (EC) was determined using a conductivity meter. The contents of total phosphorus (TP), available phosphorus (AP), total nitrogen (TN), ammonium nitrogen (NH 4 ⁺-N), nitrate nitrogen (NO 3 ⁻-N), available potassium (AK), and organic matter (OM) were analyzed by the Nanjing Institute of Soil Science. Specifically, TP and TN were quantified using the alkaline extraction colorimetric method, AP was determined by the alkaline extraction molybdenum blue colorimetric method, NH 4 ⁺-N and NO 3 ⁻-N were measured using the KCl extraction method, OM was analyzed via the potassium dichromate oxidation titration method, and AK was determined by the ammonium acetate extraction flame photometry method. The enzymatic activities in the rhizosphere soil were determined using air-dried soil samples [15]. Soil urease (S_UE) activity was measured using the sodium phenolate-sodium hypochlorite colorimetric method, while soil acid phosphatase (S_ACP) activity was quantified via the disodium phenyl phosphate colorimetric method. Soil sucrase (S_SC) and cellulase (S_CL) activities were assessed using the 3,5-dinitrosalicylic acid colorimetric method. Additionally, soil catalase (S_CAT) activity was determined by the potassium permanganate titration method. 2.5. DNA Extraction, PCR Amplification, and High-Throughput Sequencing The soil microbial community structure was analyzed using high-throughput sequencing technology. Total genomic DNA was extracted from 0.5 g of soil samples using the E.Z.N.A.® Soil DNA Kit (Omega Bio-Tek Inc., Norcross, USA), following the manufacturer’s protocol. DNA concentration and purity were assessed using a NanoDrop 2000 UV − vis spectrophotometer (Thermo Scientific, Wilmington, USA), and DNA quality was verified by 1% agarose gel electrophoresis. The V4 region of bacterial 16S rRNA genes was amplified using primers 515FmodF and 806RmodR, while fungal ITS regions were amplified using primers ITS1F and ITS2R. PCR amplification was performed using TransStart Fastpfu DNA Polymerase in a 20 µL reaction mixture, with thermal cycling conditions optimized for bacterial and fungal targets. PCR products were purified using the AxyPrep DNA Gel Extraction Kit (AxyPrep Biosciences, Union City, CA, USA) and quantified using QuantiFluor™−ST (Promega, Madison, WI, USA). Purified amplicons were sequenced on the Illumina MiSeq platform (San Diego, CA, USA) at Shanghai Majorbio Bio-Pharm Technology Co., Ltd., and raw sequence data were quality-filtered and processed as described by Chen et al. [16]. Detailed experimental procedures are provided in Text S1. 2.6. Statistical analysis The detailed analytical methods were summarized in Text S2. 3. Results and discussion 3.1. Effect of FMPs on the effective state and morphological distribution of heavy metals in soil The available contents of heavy metals in soil were determined by the DTPA extraction method, which is regarded as the most available form of elements in the soil that can be absorbed by plant roots during the growth period. Figure 1 illustrates the immobilization effectiveness of each heavy metal in the soil at various treatment remediation times and different FMPs dosages. In comparison with the CK group, the DTPA-extractable Cd, Pb, Cu, and Zn in soil were decreased by 70.10%, 99.82%, 68.30%, and 75.05% when 5 wt.% FMPs were added. Besides, the effects of FMPs on decreasing the contents of extractable heavy metals were more pronounced with increasing FMPs dosage. The immobilization mechanisms of extractable Cd, Pb, Cu, and Zn by FMPs were mainly because the main components of FMPs were composed of Fe/Mn (hydro)oxides and phosphate minerals. In which the hydroxyl groups on the surface of the Fe/Mn (hydro)oxides are deprotonated, and the free heavy metal ions could interact with the deprotonated surface hydroxyl functional groups to form mononuclear or binuclear complexes. Meanwhile, the phosphate groups on the FMPs surface could induce the adsorption of heavy metal ions and form stable phosphate mineral precipitates. Besides, electrostatic attraction and the formation of hydroxide precipitates also promoted the immobilization of Cd, Pb, Cu, and Zn in soil. The leaching toxicity of heavy metals in the soil before and after remediation was further determined by using the sulphuric acid-nitric acid method (Solid Waste. Leaching Toxicity Leaching Method Sulphuric Acid-Nitric Acid Method (HJ/T 299–2007). The results showed that the toxic leaching concentrations of Cd, Pb, Cu and Zn in the soil were reduced to less than 0.01, 0.03, 1.50 and 5.00 mg/L after 60 d of stabilization and remediation by applying 5 wt.% of FMPs (Table S2), which were by the limit of IV class standard of groundwater quality (Groundwater Quality Standard) (GB/T 14848 − 2017), and the toxicity of heavy metals in the soil was measured by sulphuric acid nitrate method (HJ /T 299–2007), and meet the remediation standard of "Technical specification for contaminated soil remediation project curing/stabilization (HJ 1282–2023)". The effect of the application of FMPs on the distribution of chemical forms of Cd, Pb, Cu, and Zn was estimated using the BCR sequential extraction method, and the results are shown in Fig. 2 . It can be seen that 60 days after the application of 5 wt.% FMPs for remediation, there was a significant reduction in the weakly acid soluble state (F1) fraction of Cd, Pb, Cu, and Zn, which is usually readily available for direct plant uptake and utilization. The F1 fractions of Cd, Pb, Cu, and Zn were reduced by 31.10%, 94.18%, 47.59%, and 18.73%, respectively, compared to the blank group. In addition, the reducible state (F2) fractions of Pb and Cu decreased, while the F2 fraction of Cd increased, and the F2 fraction of Zn did not change significantly. Furthermore, there was an increase in the oxidizable state fraction (F3) of Cd, Cu, and Zn, and a smaller change in the F3 fraction of Pb. The residual state fractions (F4) of Cd, Pb, Cu, and Zn increased significantly after treatment with FMPs and increased with the addition of FMPs. The results showed that the application of FMPs could promote the conversion of F1 or F2 fractions to F3 or F4 fractions, which further suggests that FMPs can effectively and synchronously stabilize Cd, Pb, Cu, and Zn in soil. From the above results, it can be seen that the best stabilization of heavy metal ions in soil was achieved when FMPs were applied at a rate of 5 wt.%, so subsequent studies examined the effect of 5 wt.%.% FMPs on the soil environment. 3.2. Effects of FMPs on soil properties and enzyme activities The effect of FMPs application on soil physicochemical properties is shown in Fig. 3 . Application of FMPs significantly (p < 0.05) increased soil pH and EC values, while decreasing soil Eh values, compared to the control, which favored the promotion of the formation of hydroxide precipitates from Cd, Pb, Cu, and Zn or their exchange with other cations (e.g., Na + , K + , Ca 2+ , and Mg 2+ , among others), which in turn reduced their bioavailability [17]. In addition, the contents of TP, AP, and NH 4 _N in the FMPs-restored soil were significantly increased (p < 0.05), whereas the contents of NO 3 _N and AK were significantly decreased (p < 0.05). TN and OM content did not differ significantly between the control and FMPs-treated groups. This can be mainly attributed to the fact that P is the main component of FMPs, which helps to increase the P content of the soil; in addition, FMPs may promote the growth of ammonifying bacteria and inhibit the growth of nitrifying bacteria when applied. Soil enzyme activity is an important indicator of soil health and is often used to mark the rapid response of soil microorganisms to the application of exogenous chemicals [18], and it plays a crucial role in nutrient cycling and energy transformation in soil [19]. As shown in Fig. 4 , the addition of FMPs significantly affected the activities of soil urease (S_UE), acid phosphatase (S_ACP), cellulase (S_CL), and catalase (S_CAT), while there was no significant difference in sucrase (S_SC) before and after restoration (p > 0.05). Compared with the control group, the FMPs treatment significantly reduced the S_UE activity (p < 0.05), which may be attributed to the fact that during the remediation process, the FMPs released a large amount of Fe/Mn ions in the soil, which can inhibit the S_UE activity by occupying the active center of the S_UE or by binding to the functional groups (e.g., sulfhydryl, amine, and carboxylic acid groups, etc.) on the S_UE molecule. In addition, FMPs treatment significantly (p < 0.05) increased soil S_ACP, S_CL, and S_CAT activities. The results of the Mantel test showed that the above three soil enzyme activities showed significant negative correlations with the effective state Cd, Pb, Cu, and Zn contents (Fig. S1 , p < 0.05, r < -0.5). This indicates that higher concentrations of Cd, Pb, Cu, and Zn had significant inhibitory effects on soil S_ACP, S_CL, and S_CAT activities, which is in agreement with the findings of previous studies [20]. In addition, soil S_UE, S_ACP, S_CL, and S_CAT activities were correlated with most of the soil physico-chemical factors, suggesting that changes in soil physico-chemical properties due to the incorporation of exogenous FMPs are the main drivers of soil enzyme activities. 3.3. Effects of FMPs on soil microbial community diversity Total DNA was extracted from control and FMPs5-treated soils for library construction, and a total of 51,075 16S rRNA gene sequences and 590,782 ITS gene sequences were obtained from all soil samples. Taxonomic analysis of OTU representative sequences with a sequence identity threshold of 97% was performed using the RDP classifier Bayesian algorithm. The α-diversity indices of soil bacteria and fungi are shown in Fig. S2. The diversity and richness of soil microbial communities were evaluated using Shannon, Simpson, Ace, and Chao1 indices, respectively. The diversity and abundance of bacterial communities were significantly reduced (p < 0.05), while the diversity and abundance of fungi were significantly increased (p < 0.05) after FMPs treatment compared to the control. To determine the similarities and differences in the community structure of soil samples under different treatments, the beta diversity of microbial communities was studied using PCoA analysis based on the Bray-Curtis distance. As shown in Fig. 5 , the PCoA results explained ~ 68.97% of the variation in bacterial community composition (Fig. 5 (a)) and ~ 75.35% of the variation in fungal community composition (Fig. 5 (b)), respectively. Soil samples from the same treatment group were highly similar and tended to aggregate, and there was a clear separation of soil microbial communities between the control and FMPs-treated groups, suggesting that the application of FMPs remodeled the soil microbial communities. 3.4. Effects of FMPs on the structural composition of soil microbial communities In general, toxic pollutants decrease the relative abundance of microorganisms in normal soils and increase the relative abundance of microorganisms that are resistant to heavy metals [21]. Fig. S3(a) and (b) show the relative abundance of soil microorganisms at the gate level. The dominant bacterial phyla in all soil samples were Proteobacteria, Chloroflexi, Actinobacteria, Firmicutes, Gemmatimonadota, Acidobacteriota, and Bacteroidota (Fig. S3(a)), which is in agreement with the findings of previous studies. Typically, Proteobacteria are the most abundant phylum in the soil bacterial community studied, and it is the most tolerant of HMs and can grow rapidly when the substrate is unstable [22]. In addition, some taxa in Proteobacteria can perform nitrogen fixation, denitrification, decomposition of organic matter, and sulfate reduction, and promote plant growth [23]. The addition of FMPs significantly increased the relative abundance of Chloroflexi, Acidobacteriota, and Bacteroidota, while decreasing the relative abundance of Proteobacteria, Actinobacteriota, and Gemmatimonadota compared to controls. Macrogenomic analyses have shown that Chloroflexi plays an important role in carbon cycling processes, such as sugar catabolism and CO 2 fixation [24]. Some members of Acidobacteriota contain a large number of anion/cation transporters and can grow in nutrient-poor environments [25]. Cui et al [26] also found that the relative abundance of Acidobacteriota may be significantly negatively correlated with HM concentration, which is consistent with the findings of this study. In addition, the relative abundance of Bacteroidota is positively correlated with soil pH [27], and in this study, the application of FMPs significantly increased soil pH, which may be favorable to the growth of Bacteroidota. In addition, Bacteroidota can play an important role in ensuring soil health by secreting a variety of carbohydrate-active enzymes that promote soil nutrient transformation [28]. Ascomycota and Basidiomycota were the most abundant fungal phyla, accounting for more than 90% of the total relative abundance of fungi (Fig. S3(b)). Similar results were found by Zhang et al [29], who found that Ascomycota and Basidiomycota were the most abundant taxa in HM-contaminated soil. Studies have shown that Ascomycota and Basidiomycota have a higher tolerance to heavy metals, which is conducive to creating a healthy soil environment for crop growth, and Ascomycota is more resilient than Basidiomycota, which can alleviate heavy metal stress by passivating or enriching heavy metals in the body [30]. This is consistent with the findings of the present study that the relative abundance of Ascomycota decreased and Basidiomycota increased after repair of FMPs. Basidiomycota is generally widespread in less contaminated soils [31]. In addition, Basidiomycota plays an important role in plant residue degradation, particularly of lignocellulosic organic matter [32, 33], suggesting that the application of FMPs may drive the C cycle in the soil. Microorganisms at the genus level were further analyzed for differential species abundance. As shown in Fig. S3(c), the relative abundance of the bacterial genera Truepera , Terrimonas , Sphingomonas , Luteimonas , and Flavisolibacter was significantly increased by the application of FMPs, which may be beneficial for heavy metal fixation and nutrient cycling in the soil. For example, Truepera is denitrifying and degrades organic matter such as lignocellulose [34]. In addition, Terrimonas and Luteimonas have multiple heavy metal resistances and may be potential microorganisms for remediation of heavy metal contamination [35]. Sphingomonas has been recognized as a potential microorganism for preventing plant diseases and is an important driver of C and N cycling in soil [36]. In addition, several studies have demonstrated that Sphingomonas can immobilize a variety of heavy metals such as Cd, Zn, As, Cu, and Pb [37]. This is mainly attributed to the fact that Sphingomonas contains a variety of heavy metal resistance genes, e.g., the czc manipulator enables Sphingomonas to exhibit resistance to Co, Zn, and Cd by controlling metabolic processes [38], and copA is a resistance gene for Cu, among others. Therefore, Sphingomonas has great potential for application in the remediation of heavy metal-contaminated soil. Flavisolibacter has the function of catalyzing the oxidation of hydrogen peroxide and ammonia, and it secretes acid phosphatase, fixes CO 2 , and plays an important role in soil nutrient cycling [39], and it is widely found in environments with high levels of heavy metal contamination with heavy metal fixation properties [40]. At the fungal genus level, the imposition of FMPs significantly contributed to an increase in the relative abundance of the genera Lophotrichus , Saitozyma , Pseudaleuria , Nadsonia , Thermomyces , Aspergillus , Penicillium , and Mortierella compared to the control (Fig. S3(d)). Saitozyma has been shown to produce phytase, an indispensable enzyme for hydrolyzing phytic acid to release free phosphate for nutrients [41]. Pseudaleuria fixes carbon in the soil suppresses crop pathogens and has a positive direct effect on crop yield [42]. Thermomyces can produce xylanase, which can catalyze the hydrolysis of xylan under neutral conditions, thus contributing to carbon cycling in the soil [43]. Several studies have shown that Aspergillus , Penicillium , and Mortierella have a high potential for the immobilization of a wide range of heavy metals (Cd, Pb, Cu, As, Zn, Cr, etc.) [44], and are important candidates for the bioremediation of heavy metal polluted environments. However, there are fewer studies on the role of Lophotrichus and Nadsonia in the remediation of contaminated soils. In addition, Methyloversatilis , Streptomyces , Knoellia , MND1 , Nocardioides , Gaiella , Haliangium , Acidothermus , Arthrobacter , Neocosmospora , Purpureocillium , Fusarium, Trichocladium , and Cercophora decreased in relative abundance, which may be attributed to the fact that the imposition of FMPs significantly altered the soil structure and physicochemical properties, thereby inhibiting the growth of the associated genera. The most representative taxa of soil microbial communities in different treatment groups were revealed using linear discriminant analysis (LDA) effect size (LEfSe) based analysis. As shown in Fig. 6 , different microbial taxa were significantly enriched in the soils of different treatment groups. Among them, Chloroflexi, Bacteroidota, OLB13, and Flavisolibacter were the major taxa at the phylum and genus level in the FMPs treatment group (Fig. 6 (a)). In addition, Basidiomycota , Pseudaleuria , Thermomyces , Tausonia , Remersonia , Emericellopsis , and Aphanoascus were identified as the dominant fungal taxa in the soils of the FMPs treatment group (Fig. 6 (b)). These genera are widely present in terrestrial environments and are considered ecologically beneficial microorganisms that play an important role in the cycling of nutrients such as C, N, and P, or have high heavy metal tolerance and fixation properties [45]. For example, OLB13 was identified as a denitrifying bacterium [46]. Flavisolibacter , in addition to ammonia oxidation, P solubilization, and CO 2 fixation, is also highly resistant to heavy metals and shows excellent adsorption properties for heavy metals (e.g. Cd, etc.) [40]. Pseudaleuria and Thermomyces promote C cycling in the soil. Tausonia has the ability to produce plant growth hormone-like compounds and iron carriers that solubilize inorganic P, which may play an active role in suppressing plant pests and diseases [47]. Remersonia has been shown to break down cellulose and hemicellulose and it is a core genus of fungi for humification [48]. Emericellopsis may contribute to residual carbon decomposition in soil [49]. Aphanoascus has a high heavy metal tolerance and can degrade organic matter in soil [50]. In summary, the increase in the relative abundance of these genera after FMPs remediation can promote soil nutrient cycling and heavy metal fixation, thus contributing to the improvement of the soil microcosm environment. 3.5. Effects of environmental variables on soil microbial communities The results of the correlation analysis showed that soil bacterial and fungal diversity and abundance were significantly correlated with the soil physicochemical properties tested in this study (Fig. 7 , except for TN and OM), suggesting that soil physicochemical properties affect the structural composition of bacterial and fungal communities through direct or indirect effects. In addition, the Shannon and Chao1 indices of the fungal community were negatively correlated with the concentrations of the active states Cd, Pb, Cu, and Zn in the soil, suggesting that the increase in the concentration of HM inhibited the growth of soil fungi, and similar results have been observed in other studies [29]. In contrast, there was a significant positive correlation between the diversity and abundance of bacteriophage communities and the level of active state HM in the soil, which may be attributed to the tendency of soil bacteria to adapt to heavy metal contamination and increase their diversity and abundance accordingly under conditions of persistent contamination [51]. Microbial community composition and function are driven by multiple environmental factors. As shown in Fig. S4, at the gate level (Fig. S4(a)), Actinobacteriota, Gemmatimonadota, Ascomycota, and Rozellomycota were significantly negatively correlated with soil pH, EC, TP, AP, NH 4 _N, S_ACP, S_CL, and S_CAT, and significantly correlated with Eh, NO 3 _N, AK, S_UE, A_Cd, A_Pb, A_Cu, and A_Zn; in contrast, Bacteroidota, Deinococcota, Verrucomicrobiota, and Basidiomycota were significantly positively correlated with soil pH, EC, TP, AP, NH 4 _N, S_ACP, S_CL, and S_CAT. CL and S_CAT were significantly negatively correlated with Eh, NO 3 _N, AK, S_UE, A_Cd, A_Pb, A_Cu and A_Zn. However, the relatively high abundance of Proteobacteria, Chloroflexi, and Firmicutes was not significantly correlated with most of the environmental factors tested in this study. At the genus level (Fig. S4(b)), the vast majority of genera enriched in the soil of the FMPs treatment group (e.g., Truepera , Terrimonas , Sphingomonas, Luteimonas, Flavisolibacter, OLB13, Lophotrichus, Saitozyma, Pseudaleuria, Nadsonia, Thermomyces, Aspergillus, Penicillium, Mortierella, Tausonia, Remersonia, Emericellopsis , and Aphanoascus , among others) with soil pH, EC, and TP, AP, NH 4 _N, S_ACP, S_CL and S_CAT were significantly positively correlated with Eh, NO 3 _N, AK, S_UE, A_Cd, A_Pb, A_Cu and A_Zn. These findings are consistent with previously reported results and also suggest that the application of FMPs increased the abundance of microorganisms associated with properties that promote soil nutrient cycling and reduce soil heavy metal toxicity. However, most of the genera enriched in the control soil (e.g., Methyloversatilis, Streptomyces, Knoellia, MND1, Nocardioides, Gaiella, Haliangium, Acidothermus, Arthrobacter, Neocosmospora, Purpureocillium, Fusarium , and Trichocladium , among others) were significantly negatively correlated with soil pH, EC, TP, AP, NH 4 _N, S_ACP, S_CL, and S_CAT, and significantly positively correlated with Eh, NO 3 _N, AK, S_UE, A_Cd, A_Pb, A_Cu and A_Zn were significantly positively correlated. This may be because these microorganisms have some mechanism for mitigating the toxic effects of heavy metals or can contribute to increasing their tolerance to harsh environments by regulating soil nutrients. In summary, changes in soil microbial community structure depend not only on heavy metal concentrations but also on other factors such as soil nutrients, pH, and EC. 3.6. Molecular Ecological Network Analysis Computational models of molecular ecological networks (MENs) based on random matrix theory (RMT) provide powerful tools for elucidating ecological interactions among species in microbial communities [52]. In addition, Pearson correlations are automatically constructed based on the data structure, avoiding human interference errors in identifying network attributes [53]. In this study, the RMT-based network showed symbiotic patterns of soil bacteria and fungi in the CK and FMPs treatment groups. As shown in Fig. S5 and Table S3, the number of nodes and average path distance of the bacterial network in the CK group were higher than those in the FMPs-treated group, whereas the average degree of connectivity, density, and concentration were reduced, indicating that the bacterial taxa (nodes) were more tightly connected after the FMPs repair. Compared to the CK group, the ecological network of soil fungal communities in the FMPs treatment group had fewer connections (393), lower mean degree (2.142), and lower mean clustering coefficient (0.182), indicating a lower level of complexity. In general, the more complex the ecological network, the more stable the community [54]. Therefore, it is reasonable to speculate that the complex ecological network of the CK group may be a strategy for fungi to resist heavy metal pollution and maintain the stability of ecosystem functions. In addition, differences in network topological properties suggest that bacterial networks are larger, more stable, and more complex than fungal networks, which may be related to the greater diversity and abundance of bacterial communities in the soil. Positive correlations in a network usually reflect cooperative relationships between species, while negative correlations represent competitive relationships between species in the network [53]. In this study, the proportion of positive and negative correlations in the ecological network of bacteria in the CK group was higher than that in the FMPs-treated group, suggesting that positive interactions may contribute to the enhancement of microbial tolerance to heavy metals, a hypothesis supported by Li et al [55]. Who found that phyla positively correlated with Cd (e.g., Crenarchaeota) showed more cooperative relationships in their ecological networks, whereas species in phyla negatively correlated with Cd (e.g., Planctomycetes) displayed more competitive relationships with each other. However, there was no significant difference in the proportion of positive and negative correlations in the soil fungal ecological network between the CK and FMPs treatment groups. As shown in Fig. 8 , based on the intra-module connectivity ( Zi ) value and inter-module connectivity ( Pi ) value, the whole eco-network can be categorized into four parts, which are peripheral nodes, module hubs, connectors, and network hubs. Nodes in modular hubs and connectors are often considered to be core taxa with specific effects on microbial composition and network construction [56]. In this study, the core taxa of the microbial ecological network in the soil changed significantly after the application of FMPs. The core taxa in the Bacterial Ecological Network Module Hub were mainly focused on Proteobacteria, Actinobacteria, Acidobacteriota, Bacteroidota, and Chloroflexi. The core taxa in the Fungal Ecological Network Module Hub are mainly affiliated with Ascomycota. Notably, of all the taxa identified as keystone taxa, only Vicinamibacteraceae, Gitt-GS-136, JG30-KF-CM45, Luteimonas, Nocardioidaceae, SBR1031, KD3-96, Nitrososphaeraceae, and Nectriaceae were found to have high relative abundance (> 1%) with lower relative abundance (< 1%) of the core taxa. These results suggest that some low-abundance microorganisms may be key members of the soil microbiota and have the potential to play a more important role in maintaining ecological functions than some relatively more abundant taxa [57]. For example, Sphingopyxis is considered a metal-oxidizing and denitrifying bacterium with high heavy metal tolerance and fixation capacity, as well as the ability to improve effective soil nutrients and promote plant growth [58]. Gemmata has high heavy metal resistance or detoxification [59]. In addition, a total of 228 and 223 OTUs were detected as "connectors" in the bacterial networks of the CK and FMPs treatment groups; four "connector" nodes were detected in the fungal network of the CK group, while no nodes were categorized as "connectors" in the fungal network of the FMPs treatment group. These core OTUs are mainly connected to nodes within different modules that can organize the different modules into a complete community, thus determining the efficiency of energy metabolism, material transformation, or nutrient cycling in the habitat [54]. 3.7. Processes of assembly of soil microbial communities Environmental factors (e.g., pH, temperature, nutrients, and heavy metal concentrations) have been reported to influence microbial community construction, which further affects the relative abundance and frequency of microbial occurrence in neutral or non-neutral distributions [60]. In this study, the relative importance of deterministic and stochastic processes in the assembly of soil microbial communities in the control and FMPs treatment groups was predicted using a neutral community model (NCM). As shown in Fig. 9 (a) and (a'), NCM explained 65.3%, 65.3%, and 75.1% of the changes in bacterial communities and 73.7%, 72.6%, and 83% of the changes in fungal communities in the control, FMPs-treated, and overall, respectively, suggesting that soil microbial community assemblies are more susceptible to stochastic processes. In addition, there was no significant difference in the Nm values of the bacterial community between the two treatment groups, while the Nm values of the fungal community in the FMPs-treated group (Nm = 23,000) were significantly lower than those of the control group (Nm = 30,909), suggesting that the FMPs remediation reduced the dispersal rate of the soil fungal community. The potential role of determinism and stochasticity in the phylogenetic community dynamics of bacterial and fungal communities was analyzed using the beta Nearest Taxonomic Unit Index (betaNTI) [61]. The betaNTI values of soil bacterial and fungal communities in the FMPs treatment and control groups were within − 2 and + 2 (Fig. 9 (b) and (b')), further suggesting that stochastic processes dominated the microbial community dynamics of both treatment groups [62]. In addition, the betaNTI values of soil bacterial communities after FMPs remediation showed a decreasing trend, suggesting a greater homogeneous selection of soil bacterial community assembly processes after FMPs remediation [63]. Ecological niche width characterizes a population's ability to combine various resources and community stability. As shown in Fig. 9 (c) and (c'), the width of microbial ecotopes in the FMPs treatment group was significantly higher than that of the control group, indicating that the adaptive ability of soil microorganisms to the environment was enhanced after FMPs restoration and the more adequate the diversified utilization of ecological resources, the more stable the community structure tended to be [64]. 4. Conclusion Herein, a novel multi-heavy metal stabilization material (FMPs) was utilized, exhibiting exceptional efficiency in simultaneously immobilizing Cd, Pb, Cu, and Zn in co-contaminated soils. Application of 5 wt.% FMPs for 60 days reduced DTPA-extractable Cd, Pb, Cu, and Zn by 70.10%, 99.82%, 68.30%, and 75.05%, respectively, with their leaching concentrations complying with Class IV groundwater quality standards (GB/T 14848 − 2017) and soil remediation technical specifications for solidification/stabilization (HJ 1282–2023). FMPs facilitated the transformation of Cd, Pb, Cu, and Zn from F1/F2 to more stable F3/F4 fractions, significantly increasing soil pH, EC, TP, AP, and NH 4 _N levels while enhancing S_ACP, S_CL, and S_CAT activities. Microbial community analysis revealed that FMPs treatment significantly reduced bacterial diversity and richness ( p < 0.05) but increased fungal diversity and richness ( p < 0.05). Molecular ecological network analysis demonstrated tighter bacterial node connections and reduced fungal network complexity post-remediation. Notably, certain low-abundance microbial taxa potentially played more critical roles in maintaining ecological functions than their high-abundance counterparts. Furthermore, stochastic processes predominantly governed microbial community assembly, with FMPs enhancing microbial environmental adaptability, optimizing ecological resource utilization, and stabilizing community structure. This work provides promising material and technical underpinning for the simultaneous stabilization of multi-heavy metals in co-contaminated soils. Declarations Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Supplementary materials Supplementary materials to this article can be found online. Author Contribution Rui Xu and Yuchen Shi: Conceptualization, Investigation, Funding acquisition, Data curation, Writing–original draft. Qian Li and Guangfei Qu: Conceptualization, Investigation, Data curation, Funding acquisition, Writing–review & editing. Lang Liao and Zhe Yin: Investigation, Supervision, Data curation. Yan Zhang: Investigation, Writing–review & editing. Chenyang Yin and Yaxin Tian: Supervision, Funding acquisition, Writing–review & editing, Project administration. Acknowledgments We gratefully acknowledge the support of National Natural Science Foundation of China (52400167, 51968033), and the Key Research and Development Program of Hunan Province, China (2022NK2057). Data Availability All data supporting the findings of this study are available within the paper and its Supplementary Information. References J. Faburé, M. Dufour, A. Autret, E. Uher, L.C. Fechner, Impact of an urban multi-metal contamination gradient: Metal bioaccumulation and tolerance of river biofilms collected in different seasons, Aquatic Toxicology, 159 (2015) 276-289. R.R. Pawar, Lalhmunsiama, M. Kim, J.G. Kim, S.M. Hong, S.Y. Sawant, S.M. Lee, Efficient removal of hazardous lead, cadmium, and arsenic from aqueous environment by iron oxide modified clay-activated carbon composite beads, Applied Clay Science, 162 (2018) 339-350. T.C. Egbosiuba, M.C. Egwunyenga, J.O. Tijani, S. Mustapha, A.S. Abdulkareem, A.S. Kovo, V. Krikstolaityte, A. Veksha, M. Wagner, G. Lisak, Activated multi-walled carbon nanotubes decorated with zero valent nickel nanoparticles for arsenic, cadmium and lead adsorption from wastewater in a batch and continuous flow modes, Journal of Hazardous Materials, 423 (2022) 126993. S. Khalid, M. Shahid, N.K. Niazi, B. Murtaza, I. Bibi, C. Dumat, A comparison of technologies for remediation of heavy metal contaminated soils, Journal of Geochemical Exploration, 182 (2017) 247-268. M. Komarek, A. Vanek, V. Ettler, Chemical stabilization of metals and arsenic in contaminated soils using oxides – A review, Environmental Pollution, 172 (2013) 9-22. M.Q. Shi, X.B. Min, Y. Ke, Z. Lin, Z.H. Yang, S. Wang, N. Peng, X. Yan, S. Luo, J.H. Wu, Y.J. Wei, Recent progress in understanding the mechanism of heavy metals retention by iron (oxyhydr)oxides, Science of the Total Environment, 752 (2021) 141930. A.U. Rajapaksha, M. Ahmad, M. Vithanage, K.R. Kim, J.Y. Chang, S.S. Lee, Y.S. Ok, The role of biochar, natural iron oxides, and nanomaterials as soil amendments for immobilizing metals in shooting range soil, Environmental Geochemistry and Health, 37 (2015) 931-942. T. Sun, G. Gao, W. Yang, Y. Sun, Q. Huang, L. Wang, X. Liang, High-efficiency remediation of Hg and Cd co-contaminated paddy soils by Fe–Mn oxide modified biochar and its microbial community responses, Biochar, 6 (2024) 57. P. Yin, Y. Tian, Z. Wang, R. Qu, X. Liu, Q. Xu, Q. Tang, Synthesis of functionalized silica gel with poly(diethylenetriamine bis(methylene phosphonic acid)) and its adsorption properties of transition metal ions, Materials Chemistry and Physics, 129 (2011) 168-175. P. Bhanja, J. Na, T. Jing, J. Lin, T. Wakihara, A. Bhaumik, Y. Yamauchi, Nanoarchitectured Metal Phosphates and Phosphonates: A New Material Horizon toward Emerging Applications, Chemistry of Materials, (2019). Z. Teng, X. Zhao, J. Yuan, M. Li, T. Li, Phosphate functionalized iron based nanomaterials coupled with phosphate solubilizing bacteria as an efficient remediation system to enhance lead passivation in soil, Journal of Hazardous Materials, 419 (2021) 126433. J. Song, P.C. Brookes, S. Shan, J. Xu, X. Liu, Effects of remediation agents on microbial community structure and function in soil aggregates contaminated with heavy metals, Geoderma, 425 (2022) 116030. R. Xu, Q. Li, L. Liao, Z.G. Wu, Z. Yin, Y.B. Yang, T. Jiang, Simultaneous and efficient removal of multiple heavy metal(loid)s from aqueous solutions using Fe/Mn (hydr)oxide and phosphate mineral composites synthesized by regulating the proportion of Fe(II), Fe(III), Mn (II) and PO43-, Journal of Hazardous Materials, 438 (2022) 129481. G. Rauret, J.F. Lopez-Sanchez, A. Sahuquillo, R. Rubio, C. Davidson, A. Ure, P. Quevauviller, Improvement of the BCR three step sequential extraction procedure prior to the certification of new sediment and soil reference materials, Journal of Environmental Monitoring, 1 (1999) 57-61. R. Yang, X.M. Xia, J.H. Wang, L.S. Zhu, J. Wang, Z. Ahmad, L.L. Yang, S.S. Mao, Y.Y. Chen, Dose and time-dependent response of single and combined artificial contamination of sulfamethazine and copper on soil enzymatic activities, Chemosphere, 250 (2020) 126161. L. Chen, Y. Jiang, C. Liang, Y. Luo, Q. Xu, C. Han, Q. Zhao, B. Sun, Competitive interaction with keystone taxa induced negative priming under biochar amendments, Microbiome, 7 (2019) 77. X. Qi, S.Q. Xiao, X.M. Chen, I. Ali, J.L. Gou, D. Wang, B. Zhu, W.K. Zhu, R. Shang, M.W. Han, Biochar-based microbial agent reduces U and Cd accumulation in vegetables and improves rhizosphere microecology, Journal of Hazardous Materials, 436 (2022) 129147. M. Azeem, A. Ali, P. Jeyasundar, Y.M. Li, H. Abdelrahman, A. Latif, R.H. Li, N. Basta, G. Li, S.M. Shaheen, J. Rinklebe, Z.Q. Zhang, Bone-derived biochar improved soil quality and reduced Cd and Zn phytoavailability in a multi-metal contaminated mining soil, Environmental Pollution, 277 (2021) 116800. H.Y. Hu, H. Zhou, S.X. Zhou, Z.J. Li, C.J. Wei, Y. Yu, A.G. Hay, Fomesafen impacts bacterial communities and enzyme activities in the rhizosphere, Environmental Pollution, 253 (2019) 302-311. R. Yang, X. Xia, J. Wang, L. Zhu, J. Wang, Z. Ahmad, L. Yang, S. Mao, Y. Chen, Dose and time-dependent response of single and combined artificial contamination of sulfamethazine and copper on soil enzymatic activities, Chemosphere, 250 (2020) 126161. Y.L. Xu, B. Seshadri, B. Sarkar, H.L. Wang, C. Rumpel, D. Sparks, M. Farrell, T. Hall, X.D. Yang, N. Bolan, Biochar modulates heavy metal toxicity and improves microbial carbon use efficiency in soil, Science of the Total Environment, 621 (2018) 148-159. X. Li, J. Rui, Y. Mao, A. Yannarell, R. Mackie, Dynamics of the bacterial community structure in the rhizosphere of a maize cultivar, Soil Biology and Biochemistry, 68 (2014) 392-401. B. Zhao, C. Jiao, S. Wang, D. Zhao, C. Jiang, J. Zeng, Q.L. Wu, Contrasting assembly mechanisms explain the biogeographic patterns of benthic bacterial and fungal communities on the Tibetan Plateau, Environmental Research, 214 (2022) 113836. L.A. Hug, C.J. Castelle, K.C. Wrighton, B.C. Thomas, I. Sharon, K.R. Frischkorn, K.H. Williams, S.G. Tringe, J.F. Banfield, Community genomic analyses constrain the distribution of metabolic traits across the Chloroflexi phylum and indicate roles in sediment carbon cycling, Microbiome, 1 (2013) 22. N. Fierer, C.L. Lauber, K.S. Ramirez, J. Zaneveld, M.A. Bradford, R. Knight, Comparative metagenomic, phylogenetic and physiological analyses of soil microbial communities across nitrogen gradients, The ISME journal, 6 (2012) 1007-1017. Z.J. Cui, X. Zhang, H.H. Yang, L.Q. Sun, Bioremediation of heavy metal pollution utilizing composite microbial agent of Mucor circinelloides, Actinomucor sp. and Mortierella sp, Journal of Environmental Chemical Engineering, 5 (2017) 3616-3621. Z.-L. Qu, B. Liu, Y. Ma, J. Xu, H. Sun, The response of the soil bacterial community and function to forest succession caused by forest disease, Functional Ecology, 34 (2020). J. Larsbrink, L.S. McKee, Bacteroidetes bacteria in the soil: Glycan acquisition, enzyme secretion, and gliding motility, in: G.M. Gadd, S. Sariaslani (Eds.) Advances in Applied Microbiology, Vol 110, 2020, pp. 63-98. X.P. Zhang, F.Y. Bian, Z.K. Zhong, X. Gai, C.B. Yang, Deciphering the rhizosphere microbiome of a bamboo plant in response to different chromium contamination levels, Journal of Hazardous Materials, 399 (2020) 123107. Y. Chen, Y. Chen, Y. Li, Y. Wu, Z. Zeng, R. Xu, S. Wang, H. Li, J. Zhang, Changes of heavy metal fractions during co-composting of agricultural waste and river sediment with inoculation of Phanerochaete chrysosporium, Journal of Hazardous Materials, 378 (2019) 120757. M.O. De Beeck, J. Ruytinx, M.M. Smits, J. Vangronsveld, J.V. Colpaert, F. Rineau, Belowground fungal communities in pioneer Scots pine stands growing on heavy metal polluted and non-polluted soils, Soil Biology & Biochemistry, 86 (2015) 58-66. C.B. Blackwood, M.P. Waldrop, D.R. Zak, R.L. Sinsabaugh, Molecular analysis of fungal communities and laccase genes in decomposing litter reveals differences among forest types but no impact of nitrogen deposition, Environmental Microbiology, 9 (2007) 1306-1316. D.J. Yelle, J. Ralph, F.C. Lu, K.E. Hammel, Evidence for cleavage of lignin by a brown rot basidiomycete, Environmental Microbiology, 10 (2008) 1844-1849. N. Zhu, J. Gao, D. Liang, Y. Zhu, B. Li, H. Jin, Thermal pretreatment enhances the degradation and humification of lignocellulose by stimulating thermophilic bacteria during dairy manure composting, Bioresource Technology, 319 (2021) 124149. J. She, J. Wang, X. Wei, Q. Zhang, Z. Xie, J. Beiyuan, E. Xiao, X. Yang, J. Liu, Y. Zhou, T. Xiao, Y. Wang, N. Chen, D.C.W. Tsang, Survival strategies and dominant phylotypes of maize-rhizosphere microorganisms under metal(loid)s contamination, Science of The Total Environment, 774 (2021) 145143. J. Zhu, S. Liu, H. Wang, D. Wang, Y. Zhu, J. Wang, Y. He, Q. Zheng, X. Zhan, Microplastic particles alter wheat rhizosphere soil microbial community composition and function, Journal of Hazardous Materials, 436 (2022) 129176. X. Hu, J. Wang, Y. Lv, X. Liu, J. Zhong, X. Cui, M. Zhang, D. Ma, X. Yan, X. Zhu, Effects of Heavy Metals/Metalloids and Soil Properties on Microbial Communities in Farmland in the Vicinity of a Metals Smelter, Frontiers in microbiology, 12 (2021) 707786. S. Asaf, M. Numan, A.L. Khan, A. Al-Harrasi, Sphingomonas: from diversity and genomics to functional role in environmental remediation and plant growth, Critical reviews in biotechnology, 40 (2020) 138-152. C. Liu, H. Lin, B. Li, Y. Dong, T. Yin, Responses of microbial communities and metabolic activities in the rhizosphere during phytoremediation of Cd-contaminated soil, Ecotoxicology and Environmental Safety, 202 (2020) 110958. X.G. Zhou, X.H. Zhang, C.L. Ma, F.Z. Wu, X. Jin, F. Dini-Andreote, Z. Wei, Biochar amendment reduces cadmium uptake by stimulating cadmium-resistant PGPR in tomato rhizosphere, Chemosphere, 307 (2022) 136138. A. Kurosawa, R. Nishioka, N. Aburai, K. Fujii, Isolation and Characterization of Basidiomycetous Yeasts Capable of Producing Phytase under Oligotrophic Conditions, Microorganisms, 10 (2022) 2182. Q. Ning, L. Chen, Z. Jia, C. Zhang, D. Ma, F. Li, J. Zhang, D. Li, X. Han, Z. Cai, S. Huang, W. Liu, B. Zhu, Y. Li, Multiple long-term observations reveal a strategy for soil pH-dependent fertilization and fungal communities in support of agricultural production, Agriculture, Ecosystems & Environment, 293 (2020) 106837. N.P. McHunu, K. Permaul, A.Y.A. Rahman, J.A. Saito, S. Singh, M. Alam, Xylanase Superproducer: Genome Sequence of a Compost-Loving Thermophilic Fungus, Thermomyces lanuginosus Strain SSBP, Genome Announcements, 1 (2013) e00388-00313. M.C. Manna, A. Sahu, N. De, J.K. Thakur, A. Mandal, S. Bhattacharjya, A. Ghosh, M.M. Rahman, R. Naidu, U.B. Singh, R. Dakhli, M.P. Sharma, S. Misra, Novel bio-filtration method for the removal of heavy metals from municipal solid waste, Environmental Technology & Innovation, 17 (2020) 100619. X. Zhou, X. Zhang, C. Ma, F. Wu, X. Jin, F. Dini-Andreote, Z. Wei, Biochar amendment reduces cadmium uptake by stimulating cadmium-resistant PGPR in tomato rhizosphere, Chemosphere, 307 (2022) 136138. L. Zhang, S.W. Hao, Y.P. Wang, S. Lan, Q.H. Dou, Y.Z. Peng, Rapid start-up strategy of partial denitrification and microbially driven mechanism of nitrite accumulation mediated by dissolved organic matter, Bioresource Technology, 340 (2021) 125663. A.O. Ogundeji, Y. Li, X. Liu, L. Meng, P. Sang, Y. Mu, H. Wu, Z. Ma, J. Hou, S. Li, Eggplant by grafting enhanced with biochar recruits specific microbes for disease suppression of Verticillium wilt, Applied Soil Ecology, 163 (2021) 103912. Z.J. Kong, M.M. Wang, X.T. Shi, X.D. Wang, X.K. Zhang, L.F. Chai, D.Y. Liu, Q.R. Shen, The functions of potential intermediates and fungal communities involved in the humus formation of different materials at the thermophilic phase, Bioresource Technology, 354 (2022) 127216. Y.L. Kong, Y. Kuzyakov, Y. Ruan, J.W. Zhang, T.T. Wang, M. Wang, S.W. Guo, Q.R. Shen, N. Ling, DNA Stable-Isotope Probing Delineates Carbon Flows from Rice Residues into Soil Microbial Communities Depending on Fertilization, Applied and Environmental Microbiology, 86 (2020) e02151-02119. M. Baćmaga, J. Wyszkowska, J. Kucharski, Bioaugmentation of Soil Contaminated with Azoxystrobin, Water, Air, & Soil Pollution, 228 (2016) 19. A. Bourceret, A. Cebron, E. Tisserant, P. Poupin, P. Bauda, T. Beguiristain, C. Leyval, The Bacterial and Fungal Diversity of an Aged PAH- and Heavy Metal-Contaminated Soil is Affected by Plant Cover and Edaphic Parameters, Microbial Ecology, 71 (2016) 711-724. F. Luo, J.X. Zhong, Y.F. Yang, R.H. Scheuermann, J.Z. Zhou, Application of random matrix theory to biological networks, Physics Letters A, 357 (2006) 420-423. J. Raes, P. Bork, Systems microbiology - Timeline - Molecular eco-systems biology: towards an understanding of community function, Nature Reviews Microbiology, 6 (2008) 693-699. M. Wang, S. Chen, L. Chen, D. Wang, Responses of soil microbial communities and their network interactions to saline-alkaline stress in Cd-contaminated soils, Environmental Pollution, 252 (2019) 1609-1621. X.Q. Li, D.L. Meng, J. Li, H.Q. Yin, H.W. Liu, X.D. Liu, C. Cheng, Y.H. Xiao, Z.H. Liu, M.L. Yan, Response of soil microbial communities and microbial interactions to long-term heavy metal contamination, Environmental Pollution, 231 (2017) 908-917. K. Fan, P. Weisenhorn, J.A. Gilbert, H. Chu, Wheat rhizosphere harbors a less complex and more stable microbial co-occurrence pattern than bulk soil, Soil Biology and Biochemistry, 125 (2018) 251-260. X.M. Zhang, B.D. Chen, R.B. Yin, S.P. Xing, W. Fu, H. Wu, Z.P. Hao, Y.B. Ma, X. Zhang, Long-term nickel contamination increased soil fungal diversity and altered fungal community structure and co-occurrence patterns in agricultural soils, Journal of Hazardous Materials, 436 (2022) 129113. B. Lalinská-Voleková, H. Majerová, I. Kautmanová, O. Brachtýr, D. Szabóová, D. Arendt, J. Brčeková, P. Šottník, Hydrous ferric oxides (HFO's) precipitated from contaminated waters at several abandoned Sb deposits – Interdisciplinary assessment, Science of The Total Environment, 821 (2022) 153248. B. Liu, J. Yao, B. Ma, Z.H. Chen, C.C. Zhao, X.Z. Zhu, M.M. Li, Y. Cao, W.C. Pang, H. Li, L.Y. Feng, V.G. Mihucz, R. Duran, Microbial community profiles in soils adjacent to mining and smelting areas: Contrasting potentially toxic metals and co-occurrence patterns, Chemosphere, 282 (2021) 130992. R. Logares, E.S. Lindström, S. Langenheder, J.B. Logue, H. Paterson, J. Laybourn-Parry, K. Rengefors, L. Tranvik, S. Bertilsson, Biogeography of bacterial communities exposed to progressive long-term environmental change, The ISME journal, 7 (2013) 937-948. L. Luan, C. Liang, L.J. Chen, H.T. Wang, Q.S. Xu, Y.J. Jiang, B. Sun, Coupling Bacterial Community Assembly to Microbial Metabolism across Soil Profiles, Msystems, 5 (2020) e00298-00220. W.D. Chen, K.X. Ren, A. Isabwe, H.H. Chen, M. Liu, J. Yang, Stochastic processes shape microeukaryotic community assembly in a subtropical river across wet and dry seasons (vol 7, 138, 2019), Microbiome, 7 (2019) 148. N.C. Dove, N. Tas, S.C. Hart, Ecological and genomic responses of soil microbiomes to high-severity wildfire: linking community assembly to functional potential, Isme Journal, 16 (2022) 1853-1863. E.R. Hunting, M.G. Vijver, H.G. van der Geest, C. Mulder, M.H.S. Kraak, A.M. Breure, W. Admiraal, Resource niche overlap promotes stability of bacterial community metabolism in experimental microcosms, Frontiers in microbiology, 6 (2015) 105. Additional Declarations No competing interests reported. Supplementary Files Supplementarymaterials.docx Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Revision requested 14 May, 2026 Reviews received at journal 29 Apr, 2026 Reviews received at journal 08 Apr, 2026 Reviewers agreed at journal 07 Apr, 2026 Reviews received at journal 11 Mar, 2026 Reviewers agreed at journal 24 Feb, 2026 Reviewers agreed at journal 23 Feb, 2026 Reviewers invited by journal 21 Jan, 2026 Editor assigned by journal 12 Jan, 2026 Submission checks completed at journal 12 Jan, 2026 First submitted to journal 11 Jan, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8576852","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":578689480,"identity":"40a49017-c092-4978-80d1-c35dab4f9009","order_by":0,"name":"Rui Xu","email":"","orcid":"","institution":"Kunming University of Science and Technology - Lianhua Campus","correspondingAuthor":false,"prefix":"","firstName":"Rui","middleName":"","lastName":"Xu","suffix":""},{"id":578689483,"identity":"7bcbb91a-a1d9-4189-aec5-71b1052cc272","order_by":1,"name":"Yuchen Shi","email":"","orcid":"","institution":"Kunming University of Science and Technology - Lianhua Campus","correspondingAuthor":false,"prefix":"","firstName":"Yuchen","middleName":"","lastName":"Shi","suffix":""},{"id":578689486,"identity":"a63cc8e4-eb41-4e1b-8c14-baf8f84a3355","order_by":2,"name":"Lang Liao","email":"","orcid":"","institution":"Central South University","correspondingAuthor":false,"prefix":"","firstName":"Lang","middleName":"","lastName":"Liao","suffix":""},{"id":578689493,"identity":"49bf3129-4d07-4c11-9124-5f775fbb46c3","order_by":3,"name":"Zhe Yin","email":"","orcid":"","institution":"Central South University","correspondingAuthor":false,"prefix":"","firstName":"Zhe","middleName":"","lastName":"Yin","suffix":""},{"id":578689495,"identity":"e8df4355-e0ce-4c06-b52f-45001e2972ec","order_by":4,"name":"Qian Li","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAuElEQVRIiWNgGAWjYFACxgYGBoMaOX5m5sMPSNBScMxYsp0tzYAEmz4wJxqc51GQIEqx+YzkNmkeA7YE48M8DAYMNTbRBLXI3EhsNuYxkMkzO8x74AHDsbTcBkJaJCQSGx8DbSk2O8yXYMDYcJgoLQ2HeQyYEzc38xhIEKsFZAtz4gZmorXwPGw2nGNwzFjiMDCQE4jyC3v6M4k3f4BR2X/48IMPNTaEtaCCBNKUj4JRMApGwSjABQCyujjmbk/DqwAAAABJRU5ErkJggg==","orcid":"","institution":"Central South University","correspondingAuthor":true,"prefix":"","firstName":"Qian","middleName":"","lastName":"Li","suffix":""},{"id":578689496,"identity":"6468ea9d-3dc8-4267-b070-6dff3c49c0f0","order_by":5,"name":"Guangfei Qu","email":"","orcid":"","institution":"Kunming University of Science and Technology - Lianhua Campus","correspondingAuthor":false,"prefix":"","firstName":"Guangfei","middleName":"","lastName":"Qu","suffix":""},{"id":578689499,"identity":"7604ac04-5043-4719-9c8f-5a61d2195116","order_by":6,"name":"Yan Zhang","email":"","orcid":"","institution":"Central South University","correspondingAuthor":false,"prefix":"","firstName":"Yan","middleName":"","lastName":"Zhang","suffix":""},{"id":578689500,"identity":"7786e069-1514-413e-b276-5e1813deac78","order_by":7,"name":"Chenyang Yin","email":"","orcid":"","institution":"Kunming University of Science and Technology - Lianhua Campus","correspondingAuthor":false,"prefix":"","firstName":"Chenyang","middleName":"","lastName":"Yin","suffix":""},{"id":578689501,"identity":"82f6f0aa-e828-4188-8fd4-1a38a1eecfd9","order_by":8,"name":"Yaxin Tian","email":"","orcid":"","institution":"Kunming University of Science and Technology - Lianhua Campus","correspondingAuthor":false,"prefix":"","firstName":"Yaxin","middleName":"","lastName":"Tian","suffix":""}],"badges":[],"createdAt":"2026-01-12 03:23:18","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8576852/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8576852/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":101203569,"identity":"fc4a81c8-33f6-4719-b513-c18934a2b4ae","added_by":"auto","created_at":"2026-01-27 09:40:05","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":6159656,"visible":true,"origin":"","legend":"","description":"","filename":"Manuscripts.docx","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/454faae9b0d2b5a24536ff99.docx"},{"id":100993869,"identity":"d159463c-c1cd-446e-8d8d-447b3f04731d","added_by":"auto","created_at":"2026-01-23 15:02:22","extension":"json","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":9670,"visible":true,"origin":"","legend":"","description":"","filename":"fb93bdbbfd304af2ad1f9370637368a9.json","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/ebeefed724bea31fa9172d36.json"},{"id":100993882,"identity":"c25a0878-977f-45a0-aec9-af7376daeaef","added_by":"auto","created_at":"2026-01-23 15:02:22","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":13557773,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementarymaterials.docx","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/09ab04a546703f50ea861835.docx"},{"id":101203997,"identity":"bf037ca6-d642-4f64-b90d-36fa9e57e22f","added_by":"auto","created_at":"2026-01-27 09:41:15","extension":"xml","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":108789,"visible":true,"origin":"","legend":"","description":"","filename":"fb93bdbbfd304af2ad1f9370637368a91enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/32c343cd6bfe6b0348e580c9.xml"},{"id":100993873,"identity":"534362f8-736c-42f8-ad21-d04382fabfcf","added_by":"auto","created_at":"2026-01-23 15:02:22","extension":"jpeg","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":713271,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/a16772d1bf4f525b7e704f65.jpeg"},{"id":101203735,"identity":"9610f5e8-6e89-48df-adf8-6541885d16f2","added_by":"auto","created_at":"2026-01-27 09:40:32","extension":"jpeg","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":264613,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage10.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/c65d64f67a21ed71fcd743e7.jpeg"},{"id":100993878,"identity":"42aab90b-06ce-4194-bb1d-73ce2e6f9b72","added_by":"auto","created_at":"2026-01-23 15:02:22","extension":"jpeg","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":548687,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/b32f844ceca5f1728efa35b5.jpeg"},{"id":100993884,"identity":"e0fd79a2-ac2e-4fd1-a939-be1c594bff7d","added_by":"auto","created_at":"2026-01-23 15:02:22","extension":"jpeg","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":524432,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/19c6df0d61fdd7cb79ea41ad.jpeg"},{"id":101203852,"identity":"03786b70-280d-48bc-a576-1d2e345f524a","added_by":"auto","created_at":"2026-01-27 09:40:48","extension":"jpeg","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":330990,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage4.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/8b75e4447ca888fd34b31d73.jpeg"},{"id":100993886,"identity":"1338d6d8-295f-460c-a414-c0dae3ee1f36","added_by":"auto","created_at":"2026-01-23 15:02:22","extension":"emf","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":2525884,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage5.emf","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/b06802d3541d052b914d2159.emf"},{"id":100993899,"identity":"b14a9ab4-fba3-4a3a-a36b-0a39bb669df2","added_by":"auto","created_at":"2026-01-23 15:02:23","extension":"jpeg","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":1316276,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage6.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/aa3ca2a8ef33af7d934cf8db.jpeg"},{"id":101203017,"identity":"2343e156-b8d0-49cf-b716-10715d3a8d5e","added_by":"auto","created_at":"2026-01-27 09:38:32","extension":"png","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":219373,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/711e51380bbb96eb29949bc2.png"},{"id":100993883,"identity":"6241c1e6-e551-4a3c-a3ae-9061336b4f65","added_by":"auto","created_at":"2026-01-23 15:02:22","extension":"emf","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":264824,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage8.emf","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/e794327cb047812f22a95e5e.emf"},{"id":101203768,"identity":"9ac79833-6d7b-4f4f-bee9-9afdc125c271","added_by":"auto","created_at":"2026-01-27 09:40:37","extension":"jpeg","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":900441,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage9.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/ef5f9a1fbde1e2572ec36e77.jpeg"},{"id":101203889,"identity":"a97c9d60-98aa-4387-91da-cb154f140406","added_by":"auto","created_at":"2026-01-27 09:40:50","extension":"png","order_by":14,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":78087,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/5a7040954a5ffc30fa38ae41.png"},{"id":100993885,"identity":"107b3510-0ee2-4146-ba9d-7817e7e959dd","added_by":"auto","created_at":"2026-01-23 15:02:22","extension":"png","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":52118,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage10.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/a7752647cb5ab26a72c25cf2.png"},{"id":101203412,"identity":"9396ea4d-2021-4bb4-ab15-986f18257dbe","added_by":"auto","created_at":"2026-01-27 09:39:35","extension":"png","order_by":16,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":70893,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/7979820f1fc34a574e997e59.png"},{"id":100993887,"identity":"969af2c5-6924-4762-8dbf-c222010b8ec6","added_by":"auto","created_at":"2026-01-23 15:02:23","extension":"png","order_by":17,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":95077,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/f1b54332749629e7ef37e72f.png"},{"id":100993891,"identity":"c0cd6c90-3c15-42d0-be6e-17a459495961","added_by":"auto","created_at":"2026-01-23 15:02:23","extension":"png","order_by":18,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":57251,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/0ba6ce520321c7cce9d50a03.png"},{"id":100993900,"identity":"405b6c7c-9106-42c2-80fc-2b1ba97bd03c","added_by":"auto","created_at":"2026-01-23 15:02:23","extension":"png","order_by":19,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":32262,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/90e2f09fe7215a5c436b24f7.png"},{"id":100993894,"identity":"f2391ac1-4e06-4e15-a97a-d14a2394fb40","added_by":"auto","created_at":"2026-01-23 15:02:23","extension":"png","order_by":20,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":249218,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/c2aebcc08ddb72d81f5d9230.png"},{"id":100993892,"identity":"cf4ad3d3-d060-4c1c-97e8-139a14a125a4","added_by":"auto","created_at":"2026-01-23 15:02:23","extension":"png","order_by":21,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":55710,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/1dc11a1101febd8237fd801f.png"},{"id":100993893,"identity":"453c601f-3068-4c8e-bbbd-72ea2188ec5c","added_by":"auto","created_at":"2026-01-23 15:02:23","extension":"png","order_by":22,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":20609,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage8.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/06e313716a188cc736254b2b.png"},{"id":101204237,"identity":"ec147ea8-bf0a-45ed-b770-e2151df49c4b","added_by":"auto","created_at":"2026-01-27 09:42:05","extension":"png","order_by":23,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":178216,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage9.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/dc41a3ff71a7cf7d7f18f514.png"},{"id":100993896,"identity":"608978b9-a336-44ea-a39e-eb42f099addf","added_by":"auto","created_at":"2026-01-23 15:02:23","extension":"xml","order_by":24,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":106618,"visible":true,"origin":"","legend":"","description":"","filename":"fb93bdbbfd304af2ad1f9370637368a91structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/21c721340a3bdb41904cd1cc.xml"},{"id":100993901,"identity":"eb41af7e-ba96-472e-8ca5-33e2219b9caf","added_by":"auto","created_at":"2026-01-23 15:02:23","extension":"html","order_by":25,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":114294,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/08eee9dcc4335ad3b6ad89b0.html"},{"id":100993870,"identity":"db0400da-3923-48fe-819f-aa40913d7d1b","added_by":"auto","created_at":"2026-01-23 15:02:22","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":50074,"visible":true,"origin":"","legend":"\u003cp\u003eEffects of different doses of FMPs on extractable Cd (a), Pb (b), Cu (c), and Zn (d) in soil.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/f2878a7004055a6325f52016.png"},{"id":100993868,"identity":"e6917b9e-d769-4b37-91a9-e9b877a54079","added_by":"auto","created_at":"2026-01-23 15:02:22","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":35090,"visible":true,"origin":"","legend":"\u003cp\u003eEffects of different doses on Cd (a), Pb (b), Cu (c), and Zn (d) speciation distribution in soil. F1： acid-soluble fraction; F2： reducible fraction; F3： oxidizable fraction; F4： residual fraction.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/a1b2b1141a79d0805d007008.png"},{"id":101203665,"identity":"8e4d305e-bcec-4ae7-919c-a12065136428","added_by":"auto","created_at":"2026-01-27 09:40:22","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":55646,"visible":true,"origin":"","legend":"\u003cp\u003eEffects of FMPs on pH (a), Eh (b), electrical conductivity (c), total phosphorus (TP) (d), available phosphorus (AP) (e), total nitrogen (TN) (f) ammonium nitrogen (NH\u003csub\u003e4\u003c/sub\u003e_N) (g), nitrate nitrogen (NO\u003csub\u003e3\u003c/sub\u003e_N) (h), available potassium (AK) (i) and organic matter (OM) (j) of soil.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/e2e203fd46538409021e4191.png"},{"id":101203734,"identity":"f9d30d3e-871b-4787-876b-aeb040c45064","added_by":"auto","created_at":"2026-01-27 09:40:32","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":51383,"visible":true,"origin":"","legend":"\u003cp\u003eEffects of FMPs on the activities of soil urease (S_UE) (a), acid phosphatase (S_ACP) (b), sucrose (S_SC) (c), cellulose (S_CL) (d) and catalase (S_CAT) (e) in soil\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/9e0167e14e63d9700e6a8f32.png"},{"id":100993874,"identity":"b8376a24-4b42-41c2-a709-56fb3a20c6a9","added_by":"auto","created_at":"2026-01-23 15:02:22","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":113601,"visible":true,"origin":"","legend":"\u003cp\u003ePrincipal coordinate analysis (PCoA) based on Bray-Curtis distance was used to compare the β diversity of soil bacterial (a) and fungal (b) communities between different treatment groups.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/13d5f1cf7c0efed5f5d68c25.png"},{"id":100993875,"identity":"417e3c55-5ec2-4c19-8331-cacd9f020428","added_by":"auto","created_at":"2026-01-23 15:02:22","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":331000,"visible":true,"origin":"","legend":"\u003cp\u003eLinear discriminant analysis (LDA) based effect size (LEfSe) analysis identified taxon with significant differences in (a) bacterial community and (b) fungal community among different treatment groups (from phylum level to genus level), with an absolute logarithmic LDA score threshold of 4.0 (bacterial) and 3.5 (fungal), respectively.\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/202daf1a5c36e65316fbdf57.png"},{"id":100993880,"identity":"d4c15b75-55c2-44c1-a9f4-e7caf6697691","added_by":"auto","created_at":"2026-01-23 15:02:22","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":266085,"visible":true,"origin":"","legend":"\u003cp\u003eCorrelation between soil microbial Alpha diversity and physicochemical parameters. The edge width corresponds to Mantel's r-value, and the color of the edge indicates statistical significance, pairwise correlations between variables are represented by the color gradient denoting Pearson's correlation coefficients.\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/feb1efa38a480bdb08a5ff10.png"},{"id":101204605,"identity":"36455741-9c36-446b-b014-9e7b91fe017c","added_by":"auto","created_at":"2026-01-27 09:43:34","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":45112,"visible":true,"origin":"","legend":"\u003cp\u003eThe \u003cem\u003eZi\u003c/em\u003e-\u003cem\u003ePi\u003c/em\u003e diagram is used to predict keystone taxa in the networks. Each symbol represents a node (OTU). According to the \u003cem\u003eZi\u003c/em\u003e and \u003cem\u003ePi\u003c/em\u003e values of the nodes, the ecological network can be classified into Module hubs (\u003cem\u003eZi \u003c/em\u003e\u0026gt; 2.5, \u003cem\u003ePi\u003c/em\u003e \u0026lt; 0.62), Network hubs (\u003cem\u003eZi\u003c/em\u003e\u0026gt; 2.5, \u003cem\u003ePi\u003c/em\u003e \u0026gt; 0.62), Connectors (\u003cem\u003eZi\u003c/em\u003e \u0026lt; 2.5, \u003cem\u003ePi\u003c/em\u003e \u0026gt; 0.62) and Peripherals (\u003cem\u003eZi\u003c/em\u003e\u0026lt; 2.5, \u003cem\u003ePi\u003c/em\u003e \u0026lt; 0.62). Bacterial community (a); Fungal community (b).\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/e16cb2e8d924b9282f4a4c18.png"},{"id":101203122,"identity":"c5757e2c-da24-454c-9bba-bce6edaa725e","added_by":"auto","created_at":"2026-01-27 09:38:50","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":276030,"visible":true,"origin":"","legend":"\u003cp\u003eEffects of FMPs on the assembly process of soil microbial communities. Fit of the neutral community model (NCM) of community assembly (a), R\u003csup\u003e2\u003c/sup\u003e represents the goodness of fit of NCM, and Nm represents the product of community size (N) and mobility (m) to assess the degree of intercommunity diffusion. The solid blue line represents the best fit for the neutral model, and the dashed blue line represents the 95% confidence interval around the model's prediction. Comparison of beta nearest taxon index (betaNTI) (b) and niche width (c) of soil microbial communities between different treatment groups.\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/082e10c1a365defa6c172857.png"},{"id":101880385,"identity":"d11ea6a0-557b-48f9-982f-24a299dc5d67","added_by":"auto","created_at":"2026-02-04 14:58:49","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1871373,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/09f801b7-c6a3-43ca-93bf-2d9cc7e86481.pdf"},{"id":100993888,"identity":"ceac89c6-474d-4cb3-adb4-f6a422c7077a","added_by":"auto","created_at":"2026-01-23 15:02:23","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":13557773,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementarymaterials.docx","url":"https://assets-eu.researchsquare.com/files/rs-8576852/v1/cb1c3d33940385ae9c8d15c8.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Synergistic Stabilization and Ecological Restoration in Multi-Metal Contaminated Soil: The Efficacy of Fe/Mn (Hydr)oxide-Phosphate Composites (FMPs) for Cd, Pb, Cu, Zn","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eHeavy metal contamination in soil and aquatic ecosystems has emerged as a pressing global environmental issue, driven by anthropogenic activities such as mining, industrial discharges, and agricultural practices. Heavy metals, distinguished by their environmental persistence, bioaccumulative propensity, and intrinsic toxicity, exert profound perturbations on soil ecosystem architecture and functionality upon infiltrating terrestrial systems. Their synergistic interactions with heterogeneous soil matrices amplify ecological destabilization through microbial community dysbiosis, phytotoxic inhibition of plant physiology, and irreversible degradation of pedogenic properties, ultimately jeopardizing ecosystem resilience and agroecosystem productivity. The ecotoxicological cascade extends beyond soil compartments via trophic transfer mechanisms, facilitating heavy metal bioamplification through food chains and engendering chronic human exposure risks associated with carcinogenic, neurotoxic, and teratogenic pathologies. In particular, real contaminated sites often exhibit the co-occurrence of multiple heavy metal elements, which manifests more deleterious toxicological dynamics due to the synergistic toxicity multiplier effect [1\u0026ndash;3]. Therefore, creating safe, innovative, and targeted green remediation methods that are effective and affordable has become a key research focus and a major challenge in managing contaminated soils under today\u0026rsquo;s environmental conditions.\u003c/p\u003e \u003cp\u003eThe environmental hazards associated with heavy metals primarily stem from their bioavailable fractions and their inherent lack of physiological necessity in biological systems. In contrast, the development of target-specific, synchronized multi-heavy metal remediation strategies that integrate high efficiency, economic viability, and ecological compatibility has emerged as a key scientific frontier in contemporary soil restoration research. As a paradigmatic chemoremediation strategy, in situ stabilization technologies for soil-bound heavy metals achieve contaminant immobilization through three synergistic mechanisms: (i) altering geochemical speciation via ligand-specific coordination, (ii) inducing mineral phase precipitation through pH/redox-driven crystallization, and (iii) facilitating surface complexation with reactive substrates. Collectively, these processes suppress contaminant mobility by reducing both leachable metal species and bioaccessible fractions, while preserving soil matrix integrity. Current remediation materials for heavy metal-contaminated soils predominantly include siliceous materials, calcium-based compounds, phosphorus-containing agents, organic amendments, clay minerals, metal oxides, biochar, novel nanomaterials, and composite formulations (i.e., multi-component stabilizer combinations) [4]. Critical analyses of domestic and international mechanisms and application efficacy reveal two principal limitations. First, single-component stabilizers offer limited active sites and poor selectivity, rendering them incapable of synchronously immobilizing multiple metals. Second, multi-component composites typically rely on simple physical blending rather than engineered synergistic interactions, leading to higher dosage requirements and increased operational costs. Consequently, the development of soil-specific, multifunctional materials capable of coordinated multi-metal stabilization has become a prominent research priority in the field of soil heavy metal remediation.\u003c/p\u003e \u003cp\u003eMetal (hydro)oxides, such as those of Fe, Mn, and Al, are widely present in natural environments and have been extensively employed as remediation agents for heavy metal contamination due to their large specific surface areas, amphoteric properties, and exceptional heavy metal adsorption capacities. They immobilize heavy metals through mechanisms including specific adsorption, coprecipitation, and surface complexation, predominantly occurring at -OH groups on the material surface. These surface groups typically become negatively charged (deprotonated) at high pH (Eq.\u0026nbsp;(\u003cspan refid=\"Equ1\" class=\"InternalRef\"\u003e1\u003c/span\u003e)) and positively charged (protonated) at low pH (Eq.\u0026nbsp;(\u003cspan refid=\"Equ2\" class=\"InternalRef\"\u003e2\u003c/span\u003e)), with Eq.\u0026nbsp;(\u003cspan refid=\"Equ3\" class=\"InternalRef\"\u003e3\u003c/span\u003e) illustrating the adsorption of divalent metal ions (Me\u003csup\u003e2+\u003c/sup\u003e) onto the surface groups of metal (hydro)oxides. To date, an array of naturally occurring metal (hydro) oxides, such as ferrihydrite, birnessite, goethite, magnetite, lepidocrocite, cryptomelane, aragonite, diaspore, boehmite, gibbsite, hematite, hausmannite, and maghemite, have been shown to effectively immobilize heavy metal ions [5]. Previous studies have reported that metals, including Pb, Cd, Cu, Ni, Zn, As, Sb, and Cr, can undergo natural attenuation through precipitation with metal mineral phases [6]. Rajapaksha et al. [7] demonstrated that natural iron oxides and gibbsite can reduce the NH\u003csub\u003e4\u003c/sub\u003eOAc-extractable fractions of Pb and Cu in shooting range-contaminated soils. In a related study, Sun et al. [8] synthesized Fe\u0026ndash;Mn oxide-modified biochar (FMBC), which significantly altered the composition and metabolic functions of soil bacterial communities. Notably, the relative abundances of certain phyla, such as Firmicutes, Ascomycota, and Actinobacteria, increased under FMBC treatment, thereby promoting soil heavy metal adsorption and bolstering soil ecosystem stability. Nevertheless, the practical application of both naturally occurring and synthetic metal (hydro)oxides in soil remediation is severely constrained by inherent drawbacks such as particle aggregation, poor compatibility, and insufficient selectivity toward heavy metals. In response, extensive research has focused on enhancing the immobilization efficiency of heavy metals in contaminated soils by increasing the active sites of metal (hydro)oxides or combining them with other stabilizing materials.\u003cdiv id=\"Equ1\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ1\" name=\"EquationSource\"\u003e\n$$\\:\\equiv\\:\\text{XO}{\\text{H}}_{2}^{+}\\to\\:\\equiv\\:\\text{XO}{\\text{H}}^{0}\\text{+}{\\text{H}}^{+}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e1\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Equ2\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ2\" name=\"EquationSource\"\u003e\n$$\\:\\equiv\\:\\text{XO}{\\text{H}}^{0}\\to\\:\\equiv\\:\\text{X}{\\text{O}}^{-}\\text{+}{\\text{H}}^{+}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e2\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Equ3\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ3\" name=\"EquationSource\"\u003e\n$$\\:\\equiv\\:\\text{XO}{\\text{H}}^{0}\\text{+M}{\\text{e}}^{\\text{2+}}\\to\\:\\equiv\\:\\text{XOM}{\\text{e}}^{+}\\text{+}{\\text{H}}^{+}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e3\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eRecent studies have identified phosphate groups as having exceptional cation exchange capacities, primarily attributed to the strong affinity between metal cations and phosphate ligands. This distinctive property facilitates the straightforward substitution of ions within the phosphate matrix without disrupting charge neutrality, thereby enabling effective interactions with divalent heavy metal ions (e.g. Pb\u0026sup2;⁺, Cd\u0026sup2;⁺, Zn\u0026sup2;⁺, Cu\u0026sup2;⁺) through the formation of highly insoluble metal-phosphate mineral complexes that ultimately achieve efficient metal ion stabilization [9, 10]. Mounting evidence further underscores the efficacy of phosphate-functionalized materials in soil remediation efforts. Notably, recent investigations into the synergistic application of phosphate-functionalized iron-based nanomaterials and phosphate-solubilizing bacteria (PSB) for lead-contaminated soil remediation revealed a dual mechanism: the nanomaterials mediated toxic Pb\u0026sup2;⁺ reduction and precipitation while simultaneously bolstering microbial community structure, with PSB inoculation further promoting lead stabilization through biomineralization processes [11]. In addition, Song et al. [12] demonstrated that monocalcium phosphate application effectively immobilized Cu, Zn, and Cd contaminants in soil matrices while restoring bacterial community diversity in heavy metal-impacted ecosystems. Moreover, our previous work resulted in the development of Fe-Mn (hydr)oxide-phosphate composites (FMPs) through optimized molar ratios of Fe\u003csup\u003e2+\u003c/sup\u003e, Fe\u003csup\u003e3+\u003c/sup\u003e, Mn\u003csup\u003e2+\u003c/sup\u003e, and PO\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e3\u0026minus;\u003c/sup\u003e. Comprehensive characterization revealed two predominant immobilization mechanisms in aqueous systems: 1) metal-phosphate precipitation via strong ligand complexation at surface phosphate groups, and 2) chemisorption through hydroxyl groups present on the FMPs surface. This dual mechanism afforded excellent immobilization efficiencies for Cd\u003csup\u003e2+\u003c/sup\u003e, Pb\u003csup\u003e2+\u003c/sup\u003e, Cu\u003csup\u003e2+\u003c/sup\u003e, and Zn\u003csup\u003e2+\u003c/sup\u003e in aqueous systems, highlighting the material\u0026rsquo;s promise as a multifunctional remediation agent for multi-metal contaminated environments [13]. However, no reports have yet examined the remediation efficacy or ecological restoration potential of FMPs in soils contaminated by multiple heavy metals.\u003c/p\u003e \u003cp\u003eThis paper presents a systematic investigation into the dose-dependent effects of remediation amendments (FMPs) on heavy metal(loid) bioavailability, leaching toxicity, and chemical speciation transformations in highly Cd-Pb-Cu-Zn co-contaminated soil. Through a multidimensional analysis, we comprehensively evaluated amendment-induced changes in soil physicochemical properties, enzymatic activity profiles, and microbial community structure\u0026ndash;function relationships in multi-metal co-contaminated systems. Our integrated approach reveals the critical linkages between amendment dosage, metal immobilization efficiency, and soil ecological health restoration, providing mechanistic insights into the biogeochemical processes governing heavy metal stabilization and soil functionality recovery.\u003c/p\u003e"},{"header":"2. Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1. Sample collection\u003c/h2\u003e \u003cp\u003eThe high-concentration Cd-Pb-Cu-Zn co-contaminated soil was collected from the contaminated surface soil (0\u0026thinsp;~\u0026thinsp;20 cm) in the vicinity of the Shuikoushan lead-zinc mining area (26.32\u0026deg;N, 112.29\u0026deg;E) in Changning, Hunan Province, China. The collected soil samples were thoroughly homogenized, and plant residues and gravel were removed before further analysis. The concentrations of heavy metals in the soil are presented in Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2. Preparation of FMPs\u003c/h2\u003e \u003cp\u003eAccording to our previous work [13], the FMPs material, characterized by a molar ratio of Fe\u003csup\u003e2\u003c/sup\u003e⁺: Fe\u003csup\u003e3\u003c/sup\u003e⁺: Mn\u003csup\u003e2\u003c/sup\u003e⁺: PO\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e3\u003c/sup\u003e⁻ of 1: 3: 3: 3, demonstrated exceptional performance in the liquid-phase adsorption of Cd(II), Pb(II), Cu(II), and Zn(II). Consequently, it was selected for the stabilization and remediation of Cd-Pb-Cu-Zn co-contaminated soil. Briefly, FeSO\u003csub\u003e4\u003c/sub\u003e\u0026middot;7H\u003csub\u003e2\u003c/sub\u003eO, Fe\u003csub\u003e2\u003c/sub\u003e(SO\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e3\u003c/sub\u003e\u0026middot;xH\u003csub\u003e2\u003c/sub\u003eO, and MnSO\u003csub\u003e4\u003c/sub\u003e were dissolved in water at specific molar ratios, and silica was added to prepare a mixed metal solution. Subsequently, an NH\u003csub\u003e4\u003c/sub\u003eH\u003csub\u003e2\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e solution was introduced into the mixed metal solution at a molar ratio of Fe\u003csup\u003e2\u003c/sup\u003e⁺: Fe\u003csup\u003e3\u003c/sup\u003e⁺: Mn\u003csup\u003e2\u003c/sup\u003e⁺: PO\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e3\u003c/sup\u003e⁻ of 1: 3: 3: 3 under continuous stirring. The pH of the solution was then adjusted using ammonia water, followed by further stirring, filtration, washing, drying, and grinding to obtain the FMPs material. The entire preparation process, except for drying, was conducted at room temperature.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3. Experimental design\u003c/h2\u003e \u003cp\u003eThe soil stabilization experiments were established with four distinct treatment groups. Soil samples of each contamination type were sieved through a 1 mm mesh, and 1000 g aliquots were weighed into polyethylene containers. These samples were thoroughly mixed with predetermined amounts of FMPs. The application rates of the material were determined based on the soil's bioavailable heavy metal content and the material's immobilization efficiency, set at 0%, 1% (w/w), 3% (w/w), and 5% (w/w), respectively. Each treatment was replicated three times to ensure statistical robustness. Deionized water was added to maintain soil moisture at approximately 50%, and daily gravimetric measurements were conducted to monitor and replenish water loss, ensuring consistent environmental conditions across all treatments. The polyethylene containers were placed in a natural outdoor environment to closely simulate real-world conditions, while the bioavailable heavy metal content in the soil was periodically measured. After 60 days of remediation, the soil was divided into two portions: one portion was air-dried and sieved through a 100-mesh sieve, while the other portion was immediately frozen and stored at -80\u0026deg;C for subsequent analysis. To avoid ambiguity, the application rates of 1 wt.%, 3 wt.%, and 5 wt.% were designated as FMPs1, FMPs3, and FMPs5, respectively. All reagents used in this paper are analytically pure.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.4. Analysis of soil physicochemical properties\u003c/h2\u003e \u003cp\u003eThe speciation of Cd, Pb, Cu, and Zn in the soil was determined using the BCR sequential extraction method [14], with the specific experimental procedures and extraction reagents consistent with those described in the literature. By the \u003cem\u003eTechnical Specification for Remediation of Contaminated Soil by Solidification/Stabilization\u003c/em\u003e (HJ 1282\u0026thinsp;\u0026minus;\u0026thinsp;2023), the toxicity leaching concentrations of Cd, Pb, Cu, and Zn in the soil were measured using \u003cem\u003ethe Sulfuric Acid and Nitric Acid Method for Leaching Toxicity of Solid Waste\u003c/em\u003e (HJ/T 299\u0026thinsp;\u0026minus;\u0026thinsp;2007). The experimental steps and extraction reagents strictly adhered to the standard protocols. The bioavailable concentrations of Cd, Pb, Cu, and Zn were extracted using the DTPA method. After extraction, the solutions were filtered through a 0.45 \u0026micro;m membrane, and the heavy metal concentrations were quantified using inductively coupled plasma atomic emission spectrometry (ICP\u0026thinsp;\u0026minus;\u0026thinsp;AES).\u003c/p\u003e \u003cp\u003eSoil pH and redox potential (Eh) were measured using a pH meter, while soil electrical conductivity (EC) was determined using a conductivity meter. The contents of total phosphorus (TP), available phosphorus (AP), total nitrogen (TN), ammonium nitrogen (NH\u003csub\u003e4\u003c/sub\u003e⁺-N), nitrate nitrogen (NO\u003csub\u003e3\u003c/sub\u003e⁻-N), available potassium (AK), and organic matter (OM) were analyzed by the Nanjing Institute of Soil Science. Specifically, TP and TN were quantified using the alkaline extraction colorimetric method, AP was determined by the alkaline extraction molybdenum blue colorimetric method, NH\u003csub\u003e4\u003c/sub\u003e⁺-N and NO\u003csub\u003e3\u003c/sub\u003e⁻-N were measured using the KCl extraction method, OM was analyzed via the potassium dichromate oxidation titration method, and AK was determined by the ammonium acetate extraction flame photometry method.\u003c/p\u003e \u003cp\u003eThe enzymatic activities in the rhizosphere soil were determined using air-dried soil samples [15]. Soil urease (S_UE) activity was measured using the sodium phenolate-sodium hypochlorite colorimetric method, while soil acid phosphatase (S_ACP) activity was quantified via the disodium phenyl phosphate colorimetric method. Soil sucrase (S_SC) and cellulase (S_CL) activities were assessed using the 3,5-dinitrosalicylic acid colorimetric method. Additionally, soil catalase (S_CAT) activity was determined by the potassium permanganate titration method.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e\u003cem\u003e2.5. DNA Extraction, PCR Amplification, and High-Throughput Sequencing\u003c/em\u003e\u003c/h2\u003e \u003cp\u003eThe soil microbial community structure was analyzed using high-throughput sequencing technology. Total genomic DNA was extracted from 0.5 g of soil samples using the E.Z.N.A.\u0026reg; Soil DNA Kit (Omega Bio-Tek Inc., Norcross, USA), following the manufacturer\u0026rsquo;s protocol. DNA concentration and purity were assessed using a NanoDrop 2000 UV\u0026thinsp;\u0026minus;\u0026thinsp;vis spectrophotometer (Thermo Scientific, Wilmington, USA), and DNA quality was verified by 1% agarose gel electrophoresis. The V4 region of bacterial 16S rRNA genes was amplified using primers 515FmodF and 806RmodR, while fungal ITS regions were amplified using primers ITS1F and ITS2R. PCR amplification was performed using TransStart Fastpfu DNA Polymerase in a 20 \u0026micro;L reaction mixture, with thermal cycling conditions optimized for bacterial and fungal targets. PCR products were purified using the AxyPrep DNA Gel Extraction Kit (AxyPrep Biosciences, Union City, CA, USA) and quantified using QuantiFluor\u0026trade;\u0026minus;ST (Promega, Madison, WI, USA). Purified amplicons were sequenced on the Illumina MiSeq platform (San Diego, CA, USA) at Shanghai Majorbio Bio-Pharm Technology Co., Ltd., and raw sequence data were quality-filtered and processed as described by Chen et al. [16]. Detailed experimental procedures are provided in Text S1.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e2.6. Statistical analysis\u003c/h2\u003e \u003cp\u003eThe detailed analytical methods were summarized in Text S2.\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Results and discussion","content":"\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003e3.1. Effect of FMPs on the effective state and morphological distribution of heavy metals in soil\u003c/h2\u003e \u003cp\u003eThe available contents of heavy metals in soil were determined by the DTPA extraction method, which is regarded as the most available form of elements in the soil that can be absorbed by plant roots during the growth period. Figure\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e illustrates the immobilization effectiveness of each heavy metal in the soil at various treatment remediation times and different FMPs dosages. In comparison with the CK group, the DTPA-extractable Cd, Pb, Cu, and Zn in soil were decreased by 70.10%, 99.82%, 68.30%, and 75.05% when 5 wt.% FMPs were added. Besides, the effects of FMPs on decreasing the contents of extractable heavy metals were more pronounced with increasing FMPs dosage. The immobilization mechanisms of extractable Cd, Pb, Cu, and Zn by FMPs were mainly because the main components of FMPs were composed of Fe/Mn (hydro)oxides and phosphate minerals. In which the hydroxyl groups on the surface of the Fe/Mn (hydro)oxides are deprotonated, and the free heavy metal ions could interact with the deprotonated surface hydroxyl functional groups to form mononuclear or binuclear complexes. Meanwhile, the phosphate groups on the FMPs surface could induce the adsorption of heavy metal ions and form stable phosphate mineral precipitates. Besides, electrostatic attraction and the formation of hydroxide precipitates also promoted the immobilization of Cd, Pb, Cu, and Zn in soil.\u003c/p\u003e \u003cp\u003eThe leaching toxicity of heavy metals in the soil before and after remediation was further determined by using the sulphuric acid-nitric acid method (Solid Waste.\u003c/p\u003e \u003cp\u003eLeaching Toxicity Leaching Method Sulphuric Acid-Nitric Acid Method (HJ/T 299\u0026ndash;2007). The results showed that the toxic leaching concentrations of Cd, Pb, Cu and Zn in the soil were reduced to less than 0.01, 0.03, 1.50 and 5.00 mg/L after 60 d of stabilization and remediation by applying 5 wt.% of FMPs (Table S2), which were by the limit of IV class standard of groundwater quality (Groundwater Quality Standard) (GB/T 14848\u0026thinsp;\u0026minus;\u0026thinsp;2017), and the toxicity of heavy metals in the soil was measured by sulphuric acid nitrate method (HJ /T 299\u0026ndash;2007), and meet the remediation standard of \"Technical specification for contaminated soil remediation project curing/stabilization (HJ 1282\u0026ndash;2023)\".\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe effect of the application of FMPs on the distribution of chemical forms of Cd, Pb, Cu, and Zn was estimated using the BCR sequential extraction method, and the results are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. It can be seen that 60 days after the application of 5 wt.% FMPs for remediation, there was a significant reduction in the weakly acid soluble state (F1) fraction of Cd, Pb, Cu, and Zn, which is usually readily available for direct plant uptake and utilization. The F1 fractions of Cd, Pb, Cu, and Zn were reduced by 31.10%, 94.18%, 47.59%, and 18.73%, respectively, compared to the blank group. In addition, the reducible state (F2) fractions of Pb and Cu decreased, while the F2 fraction of Cd increased, and the F2 fraction of Zn did not change significantly. Furthermore, there was an increase in the oxidizable state fraction (F3) of Cd, Cu, and Zn, and a smaller change in the F3 fraction of Pb. The residual state fractions (F4) of Cd, Pb, Cu, and Zn increased significantly after treatment with FMPs and increased with the addition of FMPs. The results showed that the application of FMPs could promote the conversion of F1 or F2 fractions to F3 or F4 fractions, which further suggests that FMPs can effectively and synchronously stabilize Cd, Pb, Cu, and Zn in soil. From the above results, it can be seen that the best stabilization of heavy metal ions in soil was achieved when FMPs were applied at a rate of 5 wt.%, so subsequent studies examined the effect of 5 wt.%.% FMPs on the soil environment.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003e3.2. Effects of FMPs on soil properties and enzyme activities\u003c/h2\u003e \u003cp\u003eThe effect of FMPs application on soil physicochemical properties is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. Application of FMPs significantly (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05) increased soil pH and EC values, while decreasing soil Eh values, compared to the control, which favored the promotion of the formation of hydroxide precipitates from Cd, Pb, Cu, and Zn or their exchange with other cations (e.g., Na\u003csup\u003e+\u003c/sup\u003e, K\u003csup\u003e+\u003c/sup\u003e, Ca\u003csup\u003e2+\u003c/sup\u003e, and Mg\u003csup\u003e2+\u003c/sup\u003e, among others), which in turn reduced their bioavailability [17]. In addition, the contents of TP, AP, and NH\u003csub\u003e4\u003c/sub\u003e_N in the FMPs-restored soil were significantly increased (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05), whereas the contents of NO\u003csub\u003e3\u003c/sub\u003e_N and AK were significantly decreased (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). TN and OM content did not differ significantly between the control and FMPs-treated groups. This can be mainly attributed to the fact that P is the main component of FMPs, which helps to increase the P content of the soil; in addition, FMPs may promote the growth of ammonifying bacteria and inhibit the growth of nitrifying bacteria when applied.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eSoil enzyme activity is an important indicator of soil health and is often used to mark the rapid response of soil microorganisms to the application of exogenous chemicals [18], and it plays a crucial role in nutrient cycling and energy transformation in soil [19]. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, the addition of FMPs significantly affected the activities of soil urease (S_UE), acid phosphatase (S_ACP), cellulase (S_CL), and catalase (S_CAT), while there was no significant difference in sucrase (S_SC) before and after restoration (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05). Compared with the control group, the FMPs treatment significantly reduced the S_UE activity (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05), which may be attributed to the fact that during the remediation process, the FMPs released a large amount of Fe/Mn ions in the soil, which can inhibit the S_UE activity by occupying the active center of the S_UE or by binding to the functional groups (e.g., sulfhydryl, amine, and carboxylic acid groups, etc.) on the S_UE molecule. In addition, FMPs treatment significantly (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05) increased soil S_ACP, S_CL, and S_CAT activities. The results of the Mantel test showed that the above three soil enzyme activities showed significant negative correlations with the effective state Cd, Pb, Cu, and Zn contents (Fig. \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e, p\u0026thinsp;\u0026lt;\u0026thinsp;0.05, r \u0026lt; -0.5). This indicates that higher concentrations of Cd, Pb, Cu, and Zn had significant inhibitory effects on soil S_ACP, S_CL, and S_CAT activities, which is in agreement with the findings of previous studies [20]. In addition, soil S_UE, S_ACP, S_CL, and S_CAT activities were correlated with most of the soil physico-chemical factors, suggesting that changes in soil physico-chemical properties due to the incorporation of exogenous FMPs are the main drivers of soil enzyme activities.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003e3.3. Effects of FMPs on soil microbial community diversity\u003c/h2\u003e \u003cp\u003eTotal DNA was extracted from control and FMPs5-treated soils for library construction, and a total of 51,075 16S rRNA gene sequences and 590,782 ITS gene sequences were obtained from all soil samples. Taxonomic analysis of OTU representative sequences with a sequence identity threshold of 97% was performed using the RDP classifier Bayesian algorithm. The α-diversity indices of soil bacteria and fungi are shown in Fig. S2. The diversity and richness of soil microbial communities were evaluated using Shannon, Simpson, Ace, and Chao1 indices, respectively. The diversity and abundance of bacterial communities were significantly reduced (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05), while the diversity and abundance of fungi were significantly increased (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05) after FMPs treatment compared to the control.\u003c/p\u003e \u003cp\u003eTo determine the similarities and differences in the community structure of soil samples under different treatments, the beta diversity of microbial communities was studied using PCoA analysis based on the Bray-Curtis distance. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e, the PCoA results explained\u0026thinsp;~\u0026thinsp;68.97% of the variation in bacterial community composition (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e(a)) and ~\u0026thinsp;75.35% of the variation in fungal community composition (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e(b)), respectively. Soil samples from the same treatment group were highly similar and tended to aggregate, and there was a clear separation of soil microbial communities between the control and FMPs-treated groups, suggesting that the application of FMPs remodeled the soil microbial communities.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003e3.4. Effects of FMPs on the structural composition of soil microbial communities\u003c/h2\u003e \u003cp\u003eIn general, toxic pollutants decrease the relative abundance of microorganisms in normal soils and increase the relative abundance of microorganisms that are resistant to heavy metals [21]. Fig. S3(a) and (b) show the relative abundance of soil microorganisms at the gate level. The dominant bacterial phyla in all soil samples were Proteobacteria, Chloroflexi, Actinobacteria, Firmicutes, Gemmatimonadota, Acidobacteriota, and Bacteroidota (Fig. S3(a)), which is in agreement with the findings of previous studies. Typically, Proteobacteria are the most abundant phylum in the soil bacterial community studied, and it is the most tolerant of HMs and can grow rapidly when the substrate is unstable [22]. In addition, some taxa in Proteobacteria can perform nitrogen fixation, denitrification, decomposition of organic matter, and sulfate reduction, and promote plant growth [23]. The addition of FMPs significantly increased the relative abundance of Chloroflexi, Acidobacteriota, and Bacteroidota, while decreasing the relative abundance of Proteobacteria, Actinobacteriota, and Gemmatimonadota compared to controls. Macrogenomic analyses have shown that Chloroflexi plays an important role in carbon cycling processes, such as sugar catabolism and CO\u003csub\u003e2\u003c/sub\u003e fixation [24]. Some members of Acidobacteriota contain a large number of anion/cation transporters and can grow in nutrient-poor environments [25]. Cui et al [26] also found that the relative abundance of Acidobacteriota may be significantly negatively correlated with HM concentration, which is consistent with the findings of this study. In addition, the relative abundance of Bacteroidota is positively correlated with soil pH [27], and in this study, the application of FMPs significantly increased soil pH, which may be favorable to the growth of Bacteroidota. In addition, Bacteroidota can play an important role in ensuring soil health by secreting a variety of carbohydrate-active enzymes that promote soil nutrient transformation [28].\u003c/p\u003e \u003cp\u003eAscomycota and Basidiomycota were the most abundant fungal phyla, accounting for more than 90% of the total relative abundance of fungi (Fig. S3(b)). Similar results were found by Zhang et al [29], who found that Ascomycota and Basidiomycota were the most abundant taxa in HM-contaminated soil. Studies have shown that Ascomycota and Basidiomycota have a higher tolerance to heavy metals, which is conducive to creating a healthy soil environment for crop growth, and Ascomycota is more resilient than Basidiomycota, which can alleviate heavy metal stress by passivating or enriching heavy metals in the body [30]. This is consistent with the findings of the present study that the relative abundance of Ascomycota decreased and Basidiomycota increased after repair of FMPs. Basidiomycota is generally widespread in less contaminated soils [31]. In addition, Basidiomycota plays an important role in plant residue degradation, particularly of lignocellulosic organic matter [32, 33], suggesting that the application of FMPs may drive the C cycle in the soil.\u003c/p\u003e \u003cp\u003eMicroorganisms at the genus level were further analyzed for differential species abundance. As shown in Fig. S3(c), the relative abundance of the bacterial genera \u003cem\u003eTruepera\u003c/em\u003e, \u003cem\u003eTerrimonas\u003c/em\u003e, \u003cem\u003eSphingomonas\u003c/em\u003e, \u003cem\u003eLuteimonas\u003c/em\u003e, and \u003cem\u003eFlavisolibacter\u003c/em\u003e was significantly increased by the application of FMPs, which may be beneficial for heavy metal fixation and nutrient cycling in the soil. For example, \u003cem\u003eTruepera\u003c/em\u003e is denitrifying and degrades organic matter such as lignocellulose [34]. In addition, \u003cem\u003eTerrimonas\u003c/em\u003e and \u003cem\u003eLuteimonas\u003c/em\u003e have multiple heavy metal resistances and may be potential microorganisms for remediation of heavy metal contamination [35]. \u003cem\u003eSphingomonas\u003c/em\u003e has been recognized as a potential microorganism for preventing plant diseases and is an important driver of C and N cycling in soil [36]. In addition, several studies have demonstrated that \u003cem\u003eSphingomonas\u003c/em\u003e can immobilize a variety of heavy metals such as Cd, Zn, As, Cu, and Pb [37]. This is mainly attributed to the fact that \u003cem\u003eSphingomonas\u003c/em\u003e contains a variety of heavy metal resistance genes, e.g., the czc manipulator enables \u003cem\u003eSphingomonas\u003c/em\u003e to exhibit resistance to Co, Zn, and Cd by controlling metabolic processes [38], and copA is a resistance gene for Cu, among others. Therefore, \u003cem\u003eSphingomonas\u003c/em\u003e has great potential for application in the remediation of heavy metal-contaminated soil. \u003cem\u003eFlavisolibacter\u003c/em\u003e has the function of catalyzing the oxidation of hydrogen peroxide and ammonia, and it secretes acid phosphatase, fixes CO\u003csub\u003e2\u003c/sub\u003e, and plays an important role in soil nutrient cycling [39], and it is widely found in environments with high levels of heavy metal contamination with heavy metal fixation properties [40].\u003c/p\u003e \u003cp\u003eAt the fungal genus level, the imposition of FMPs significantly contributed to an increase in the relative abundance of the genera \u003cem\u003eLophotrichus\u003c/em\u003e, \u003cem\u003eSaitozyma\u003c/em\u003e, \u003cem\u003ePseudaleuria\u003c/em\u003e, \u003cem\u003eNadsonia\u003c/em\u003e, \u003cem\u003eThermomyces\u003c/em\u003e, \u003cem\u003eAspergillus\u003c/em\u003e, \u003cem\u003ePenicillium\u003c/em\u003e, and \u003cem\u003eMortierella\u003c/em\u003e compared to the control (Fig. S3(d)). Saitozyma has been shown to produce phytase, an indispensable enzyme for hydrolyzing phytic acid to release free phosphate for nutrients [41]. \u003cem\u003ePseudaleuria\u003c/em\u003e fixes carbon in the soil suppresses crop pathogens and has a positive direct effect on crop yield [42]. \u003cem\u003eThermomyces\u003c/em\u003e can produce xylanase, which can catalyze the hydrolysis of xylan under neutral conditions, thus contributing to carbon cycling in the soil [43]. Several studies have shown that \u003cem\u003eAspergillus\u003c/em\u003e, \u003cem\u003ePenicillium\u003c/em\u003e, and \u003cem\u003eMortierella\u003c/em\u003e have a high potential for the immobilization of a wide range of heavy metals (Cd, Pb, Cu, As, Zn, Cr, etc.) [44], and are important candidates for the bioremediation of heavy metal polluted environments. However, there are fewer studies on the role of \u003cem\u003eLophotrichus\u003c/em\u003e and \u003cem\u003eNadsonia\u003c/em\u003e in the remediation of contaminated soils. In addition, \u003cem\u003eMethyloversatilis\u003c/em\u003e, \u003cem\u003eStreptomyces\u003c/em\u003e, \u003cem\u003eKnoellia\u003c/em\u003e, \u003cem\u003eMND1\u003c/em\u003e, \u003cem\u003eNocardioides\u003c/em\u003e, \u003cem\u003eGaiella\u003c/em\u003e, \u003cem\u003eHaliangium\u003c/em\u003e, \u003cem\u003eAcidothermus\u003c/em\u003e, \u003cem\u003eArthrobacter\u003c/em\u003e, \u003cem\u003eNeocosmospora\u003c/em\u003e, \u003cem\u003ePurpureocillium\u003c/em\u003e, \u003cem\u003eFusarium, Trichocladium\u003c/em\u003e, and \u003cem\u003eCercophora\u003c/em\u003e decreased in relative abundance, which may be attributed to the fact that the imposition of FMPs significantly altered the soil structure and physicochemical properties, thereby inhibiting the growth of the associated genera.\u003c/p\u003e \u003cp\u003eThe most representative taxa of soil microbial communities in different treatment groups were revealed using linear discriminant analysis (LDA) effect size (LEfSe) based analysis. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e, different microbial taxa were significantly enriched in the soils of different treatment groups. Among them, Chloroflexi, Bacteroidota, OLB13, and Flavisolibacter were the major taxa at the phylum and genus level in the FMPs treatment group (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e(a)). In addition, \u003cem\u003eBasidiomycota\u003c/em\u003e, \u003cem\u003ePseudaleuria\u003c/em\u003e, \u003cem\u003eThermomyces\u003c/em\u003e, \u003cem\u003eTausonia\u003c/em\u003e, \u003cem\u003eRemersonia\u003c/em\u003e, \u003cem\u003eEmericellopsis\u003c/em\u003e, and \u003cem\u003eAphanoascus\u003c/em\u003e were identified as the dominant fungal taxa in the soils of the FMPs treatment group (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e(b)). These genera are widely present in terrestrial environments and are considered ecologically beneficial microorganisms that play an important role in the cycling of nutrients such as C, N, and P, or have high heavy metal tolerance and fixation properties [45]. For example, OLB13 was identified as a denitrifying bacterium [46]. \u003cem\u003eFlavisolibacter\u003c/em\u003e, in addition to ammonia oxidation, P solubilization, and CO\u003csub\u003e2\u003c/sub\u003e fixation, is also highly resistant to heavy metals and shows excellent adsorption properties for heavy metals (e.g. Cd, etc.) [40]. \u003cem\u003ePseudaleuria\u003c/em\u003e and \u003cem\u003eThermomyces\u003c/em\u003e promote C cycling in the soil. Tausonia has the ability to produce plant growth hormone-like compounds and iron carriers that solubilize inorganic P, which may play an active role in suppressing plant pests and diseases [47]. \u003cem\u003eRemersonia\u003c/em\u003e has been shown to break down cellulose and hemicellulose and it is a core genus of fungi for humification [48]. \u003cem\u003eEmericellopsis\u003c/em\u003e may contribute to residual carbon decomposition in soil [49]. \u003cem\u003eAphanoascus\u003c/em\u003e has a high heavy metal tolerance and can degrade organic matter in soil [50]. In summary, the increase in the relative abundance of these genera after FMPs remediation can promote soil nutrient cycling and heavy metal fixation, thus contributing to the improvement of the soil microcosm environment.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003e3.5. Effects of environmental variables on soil microbial communities\u003c/h2\u003e \u003cp\u003eThe results of the correlation analysis showed that soil bacterial and fungal diversity and abundance were significantly correlated with the soil physicochemical properties tested in this study (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e, except for TN and OM), suggesting that soil physicochemical properties affect the structural composition of bacterial and fungal communities through direct or indirect effects. In addition, the Shannon and Chao1 indices of the fungal community were negatively correlated with the concentrations of the active states Cd, Pb, Cu, and Zn in the soil, suggesting that the increase in the concentration of HM inhibited the growth of soil fungi, and similar results have been observed in other studies [29]. In contrast, there was a significant positive correlation between the diversity and abundance of bacteriophage communities and the level of active state HM in the soil, which may be attributed to the tendency of soil bacteria to adapt to heavy metal contamination and increase their diversity and abundance accordingly under conditions of persistent contamination [51].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eMicrobial community composition and function are driven by multiple environmental factors. As shown in Fig. S4, at the gate level (Fig. S4(a)), Actinobacteriota, Gemmatimonadota, Ascomycota, and Rozellomycota were significantly negatively correlated with soil pH, EC, TP, AP, NH\u003csub\u003e4\u003c/sub\u003e_N, S_ACP, S_CL, and S_CAT, and significantly correlated with Eh, NO\u003csub\u003e3\u003c/sub\u003e_N, AK, S_UE, A_Cd, A_Pb, A_Cu, and A_Zn; in contrast, Bacteroidota, Deinococcota, Verrucomicrobiota, and Basidiomycota were significantly positively correlated with soil pH, EC, TP, AP, NH\u003csub\u003e4\u003c/sub\u003e_N, S_ACP, S_CL, and S_CAT. CL and S_CAT were significantly negatively correlated with Eh, NO\u003csub\u003e3\u003c/sub\u003e_N, AK, S_UE, A_Cd, A_Pb, A_Cu and A_Zn. However, the relatively high abundance of Proteobacteria, Chloroflexi, and Firmicutes was not significantly correlated with most of the environmental factors tested in this study.\u003c/p\u003e \u003cp\u003eAt the genus level (Fig. S4(b)), the vast majority of genera enriched in the soil of the FMPs treatment group (e.g., \u003cem\u003eTruepera\u003c/em\u003e, \u003cem\u003eTerrimonas\u003c/em\u003e, \u003cem\u003eSphingomonas, Luteimonas, Flavisolibacter, OLB13, Lophotrichus, Saitozyma, Pseudaleuria, Nadsonia, Thermomyces, Aspergillus, Penicillium, Mortierella, Tausonia, Remersonia, Emericellopsis\u003c/em\u003e, and \u003cem\u003eAphanoascus\u003c/em\u003e, among others) with soil pH, EC, and TP, AP, NH\u003csub\u003e4\u003c/sub\u003e_N, S_ACP, S_CL and S_CAT were significantly positively correlated with Eh, NO\u003csub\u003e3\u003c/sub\u003e_N, AK, S_UE, A_Cd, A_Pb, A_Cu and A_Zn. These findings are consistent with previously reported results and also suggest that the application of FMPs increased the abundance of microorganisms associated with properties that promote soil nutrient cycling and reduce soil heavy metal toxicity. However, most of the genera enriched in the control soil (e.g., \u003cem\u003eMethyloversatilis, Streptomyces, Knoellia, MND1, Nocardioides, Gaiella, Haliangium, Acidothermus, Arthrobacter, Neocosmospora, Purpureocillium, Fusarium\u003c/em\u003e, and \u003cem\u003eTrichocladium\u003c/em\u003e, among others) were significantly negatively correlated with soil pH, EC, TP, AP, NH\u003csub\u003e4\u003c/sub\u003e_N, S_ACP, S_CL, and S_CAT, and significantly positively correlated with Eh, NO\u003csub\u003e3\u003c/sub\u003e_N, AK, S_UE, A_Cd, A_Pb, A_Cu and A_Zn were significantly positively correlated. This may be because these microorganisms have some mechanism for mitigating the toxic effects of heavy metals or can contribute to increasing their tolerance to harsh environments by regulating soil nutrients. In summary, changes in soil microbial community structure depend not only on heavy metal concentrations but also on other factors such as soil nutrients, pH, and EC.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003e3.6. Molecular Ecological Network Analysis\u003c/h2\u003e \u003cp\u003eComputational models of molecular ecological networks (MENs) based on random matrix theory (RMT) provide powerful tools for elucidating ecological interactions among species in microbial communities [52]. In addition, Pearson correlations are automatically constructed based on the data structure, avoiding human interference errors in identifying network attributes [53]. In this study, the RMT-based network showed symbiotic patterns of soil bacteria and fungi in the CK and FMPs treatment groups. As shown in Fig. S5 and Table S3, the number of nodes and average path distance of the bacterial network in the CK group were higher than those in the FMPs-treated group, whereas the average degree of connectivity, density, and concentration were reduced, indicating that the bacterial taxa (nodes) were more tightly connected after the FMPs repair. Compared to the CK group, the ecological network of soil fungal communities in the FMPs treatment group had fewer connections (393), lower mean degree (2.142), and lower mean clustering coefficient (0.182), indicating a lower level of complexity. In general, the more complex the ecological network, the more stable the community [54]. Therefore, it is reasonable to speculate that the complex ecological network of the CK group may be a strategy for fungi to resist heavy metal pollution and maintain the stability of ecosystem functions. In addition, differences in network topological properties suggest that bacterial networks are larger, more stable, and more complex than fungal networks, which may be related to the greater diversity and abundance of bacterial communities in the soil. Positive correlations in a network usually reflect cooperative relationships between species, while negative correlations represent competitive relationships between species in the network [53]. In this study, the proportion of positive and negative correlations in the ecological network of bacteria in the CK group was higher than that in the FMPs-treated group, suggesting that positive interactions may contribute to the enhancement of microbial tolerance to heavy metals, a hypothesis supported by Li et al [55]. Who found that phyla positively correlated with Cd (e.g., Crenarchaeota) showed more cooperative relationships in their ecological networks, whereas species in phyla negatively correlated with Cd (e.g., Planctomycetes) displayed more competitive relationships with each other. However, there was no significant difference in the proportion of positive and negative correlations in the soil fungal ecological network between the CK and FMPs treatment groups.\u003c/p\u003e \u003cp\u003eAs shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003e, based on the intra-module connectivity (\u003cem\u003eZi\u003c/em\u003e) value and inter-module connectivity (\u003cem\u003ePi\u003c/em\u003e) value, the whole eco-network can be categorized into four parts, which are peripheral nodes, module hubs, connectors, and network hubs. Nodes in modular hubs and connectors are often considered to be core taxa with specific effects on microbial composition and network construction [56]. In this study, the core taxa of the microbial ecological network in the soil changed significantly after the application of FMPs. The core taxa in the Bacterial Ecological Network Module Hub were mainly focused on Proteobacteria, Actinobacteria, Acidobacteriota, Bacteroidota, and Chloroflexi. The core taxa in the Fungal Ecological Network Module Hub are mainly affiliated with Ascomycota. Notably, of all the taxa identified as keystone taxa, only Vicinamibacteraceae, Gitt-GS-136, JG30-KF-CM45, Luteimonas, Nocardioidaceae, SBR1031, KD3-96, Nitrososphaeraceae, and Nectriaceae were found to have high relative abundance (\u0026gt;\u0026thinsp;1%) with lower relative abundance (\u0026lt;\u0026thinsp;1%) of the core taxa. These results suggest that some low-abundance microorganisms may be key members of the soil microbiota and have the potential to play a more important role in maintaining ecological functions than some relatively more abundant taxa [57]. For example, \u003cem\u003eSphingopyxis\u003c/em\u003e is considered a metal-oxidizing and denitrifying bacterium with high heavy metal tolerance and fixation capacity, as well as the ability to improve effective soil nutrients and promote plant growth [58]. \u003cem\u003eGemmata\u003c/em\u003e has high heavy metal resistance or detoxification [59]. In addition, a total of 228 and 223 OTUs were detected as \"connectors\" in the bacterial networks of the CK and FMPs treatment groups; four \"connector\" nodes were detected in the fungal network of the CK group, while no nodes were categorized as \"connectors\" in the fungal network of the FMPs treatment group. These core OTUs are mainly connected to nodes within different modules that can organize the different modules into a complete community, thus determining the efficiency of energy metabolism, material transformation, or nutrient cycling in the habitat [54].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003e3.7. Processes of assembly of soil microbial communities\u003c/h2\u003e \u003cp\u003eEnvironmental factors (e.g., pH, temperature, nutrients, and heavy metal concentrations) have been reported to influence microbial community construction, which further affects the relative abundance and frequency of microbial occurrence in neutral or non-neutral distributions [60]. In this study, the relative importance of deterministic and stochastic processes in the assembly of soil microbial communities in the control and FMPs treatment groups was predicted using a neutral community model (NCM). As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e9\u003c/span\u003e(a) and (a'), NCM explained 65.3%, 65.3%, and 75.1% of the changes in bacterial communities and 73.7%, 72.6%, and 83% of the changes in fungal communities in the control, FMPs-treated, and overall, respectively, suggesting that soil microbial community assemblies are more susceptible to stochastic processes. In addition, there was no significant difference in the Nm values of the bacterial community between the two treatment groups, while the Nm values of the fungal community in the FMPs-treated group (Nm\u0026thinsp;=\u0026thinsp;23,000) were significantly lower than those of the control group (Nm\u0026thinsp;=\u0026thinsp;30,909), suggesting that the FMPs remediation reduced the dispersal rate of the soil fungal community. The potential role of determinism and stochasticity in the phylogenetic community dynamics of bacterial and fungal communities was analyzed using the beta Nearest Taxonomic Unit Index (betaNTI) [61]. The betaNTI values of soil bacterial and fungal communities in the FMPs treatment and control groups were within \u0026minus;\u0026thinsp;2 and +\u0026thinsp;2 (Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e9\u003c/span\u003e(b) and (b')), further suggesting that stochastic processes dominated the microbial community dynamics of both treatment groups [62]. In addition, the betaNTI values of soil bacterial communities after FMPs remediation showed a decreasing trend, suggesting a greater homogeneous selection of soil bacterial community assembly processes after FMPs remediation [63]. Ecological niche width characterizes a population's ability to combine various resources and community stability. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e9\u003c/span\u003e(c) and (c'), the width of microbial ecotopes in the FMPs treatment group was significantly higher than that of the control group, indicating that the adaptive ability of soil microorganisms to the environment was enhanced after FMPs restoration and the more adequate the diversified utilization of ecological resources, the more stable the community structure tended to be [64].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"4. Conclusion","content":"\u003cp\u003eHerein, a novel multi-heavy metal stabilization material (FMPs) was utilized, exhibiting exceptional efficiency in simultaneously immobilizing Cd, Pb, Cu, and Zn in co-contaminated soils. Application of 5 wt.% FMPs for 60 days reduced DTPA-extractable Cd, Pb, Cu, and Zn by 70.10%, 99.82%, 68.30%, and 75.05%, respectively, with their leaching concentrations complying with Class IV groundwater quality standards (GB/T 14848\u0026thinsp;\u0026minus;\u0026thinsp;2017) and soil remediation technical specifications for solidification/stabilization (HJ 1282\u0026ndash;2023). FMPs facilitated the transformation of Cd, Pb, Cu, and Zn from F1/F2 to more stable F3/F4 fractions, significantly increasing soil pH, EC, TP, AP, and NH\u003csub\u003e4\u003c/sub\u003e_N levels while enhancing S_ACP, S_CL, and S_CAT activities. Microbial community analysis revealed that FMPs treatment significantly reduced bacterial diversity and richness (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05) but increased fungal diversity and richness (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Molecular ecological network analysis demonstrated tighter bacterial node connections and reduced fungal network complexity post-remediation. Notably, certain low-abundance microbial taxa potentially played more critical roles in maintaining ecological functions than their high-abundance counterparts. Furthermore, stochastic processes predominantly governed microbial community assembly, with FMPs enhancing microbial environmental adaptability, optimizing ecological resource utilization, and stabilizing community structure. This work provides promising material and technical underpinning for the simultaneous stabilization of multi-heavy metals in co-contaminated soils.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eDeclaration of Competing Interest\u003c/h2\u003e \u003cp\u003eThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.\u003c/p\u003e\u003ch2\u003eSupplementary materials\u003c/h2\u003e \u003cp\u003eSupplementary materials to this article can be found online.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eRui Xu and Yuchen Shi: Conceptualization, Investigation, Funding acquisition, Data curation, Writing\u0026ndash;original draft. Qian Li and Guangfei Qu: Conceptualization, Investigation, Data curation, Funding acquisition, Writing\u0026ndash;review \u0026amp; editing. Lang Liao and Zhe Yin: Investigation, Supervision, Data curation. Yan Zhang: Investigation, Writing\u0026ndash;review \u0026amp; editing. Chenyang Yin and Yaxin Tian: Supervision, Funding acquisition, Writing\u0026ndash;review \u0026amp; editing, Project administration.\u003c/p\u003e\u003ch2\u003eAcknowledgments\u003c/h2\u003e \u003cp\u003eWe gratefully acknowledge the support of National Natural Science Foundation of China (52400167, 51968033), and the Key Research and Development Program of Hunan Province, China (2022NK2057).\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eAll data supporting the findings of this study are available within the paper and its Supplementary Information.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eJ. Fabur\u0026eacute;, M. Dufour, A. Autret, E. Uher, L.C. Fechner, Impact of an urban multi-metal contamination gradient: Metal bioaccumulation and tolerance of river biofilms collected in different seasons, Aquatic Toxicology, 159 (2015) 276-289.\u003c/li\u003e\n\u003cli\u003eR.R. Pawar, Lalhmunsiama, M. Kim, J.G. Kim, S.M. Hong, S.Y. Sawant, S.M. Lee, Efficient removal of hazardous lead, cadmium, and arsenic from aqueous environment by iron oxide modified clay-activated carbon composite beads, Applied Clay Science, 162 (2018) 339-350.\u003c/li\u003e\n\u003cli\u003eT.C. Egbosiuba, M.C. Egwunyenga, J.O. Tijani, S. Mustapha, A.S. Abdulkareem, A.S. Kovo, V. Krikstolaityte, A. Veksha, M. Wagner, G. Lisak, Activated multi-walled carbon nanotubes decorated with zero valent nickel nanoparticles for arsenic, cadmium and lead adsorption from wastewater in a batch and continuous flow modes, Journal of Hazardous Materials, 423 (2022) 126993.\u003c/li\u003e\n\u003cli\u003eS. Khalid, M. Shahid, N.K. Niazi, B. Murtaza, I. Bibi, C. Dumat, A comparison of technologies for remediation of heavy metal contaminated soils, Journal of Geochemical Exploration, 182 (2017) 247-268.\u003c/li\u003e\n\u003cli\u003eM. Komarek, A. Vanek, V. Ettler, Chemical stabilization of metals and arsenic in contaminated soils using oxides \u0026ndash; A review, Environmental Pollution, 172 (2013) 9-22.\u003c/li\u003e\n\u003cli\u003eM.Q. Shi, X.B. Min, Y. Ke, Z. Lin, Z.H. Yang, S. Wang, N. Peng, X. Yan, S. Luo, J.H. Wu, Y.J. Wei, Recent progress in understanding the mechanism of heavy metals retention by iron (oxyhydr)oxides, Science of the Total Environment, 752 (2021) 141930.\u003c/li\u003e\n\u003cli\u003eA.U. Rajapaksha, M. Ahmad, M. Vithanage, K.R. Kim, J.Y. Chang, S.S. Lee, Y.S. Ok, The role of biochar, natural iron oxides, and nanomaterials as soil amendments for immobilizing metals in shooting range soil, Environmental Geochemistry and Health, 37 (2015) 931-942.\u003c/li\u003e\n\u003cli\u003eT. Sun, G. Gao, W. Yang, Y. Sun, Q. Huang, L. Wang, X. Liang, High-efficiency remediation of Hg and Cd co-contaminated paddy soils by Fe\u0026ndash;Mn oxide modified biochar and its microbial community responses, Biochar, 6 (2024) 57.\u003c/li\u003e\n\u003cli\u003eP. Yin, Y. Tian, Z. Wang, R. Qu, X. Liu, Q. Xu, Q. Tang, Synthesis of functionalized silica gel with poly(diethylenetriamine bis(methylene phosphonic acid)) and its adsorption properties of transition metal ions, Materials Chemistry and Physics, 129 (2011) 168-175.\u003c/li\u003e\n\u003cli\u003eP. Bhanja, J. Na, T. Jing, J. Lin, T. Wakihara, A. Bhaumik, Y. Yamauchi, Nanoarchitectured Metal Phosphates and Phosphonates: A New Material Horizon toward Emerging Applications, Chemistry of Materials, (2019).\u003c/li\u003e\n\u003cli\u003eZ. Teng, X. Zhao, J. Yuan, M. Li, T. Li, Phosphate functionalized iron based nanomaterials coupled with phosphate solubilizing bacteria as an efficient remediation system to enhance lead passivation in soil, Journal of Hazardous Materials, 419 (2021) 126433.\u003c/li\u003e\n\u003cli\u003eJ. Song, P.C. Brookes, S. Shan, J. Xu, X. Liu, Effects of remediation agents on microbial community structure and function in soil aggregates contaminated with heavy metals, Geoderma, 425 (2022) 116030.\u003c/li\u003e\n\u003cli\u003eR. Xu, Q. Li, L. Liao, Z.G. Wu, Z. Yin, Y.B. Yang, T. Jiang, Simultaneous and efficient removal of multiple heavy metal(loid)s from aqueous solutions using Fe/Mn (hydr)oxide and phosphate mineral composites synthesized by regulating the proportion of Fe(II), Fe(III), Mn (II) and PO\u0026lt;sub\u0026gt;4\u0026lt;/sub\u0026gt;\u0026lt;SUP\u0026gt;3-\u0026lt;/SUP\u0026gt;, Journal of Hazardous Materials, 438 (2022) 129481.\u003c/li\u003e\n\u003cli\u003eG. Rauret, J.F. Lopez-Sanchez, A. Sahuquillo, R. Rubio, C. Davidson, A. Ure, P. Quevauviller, Improvement of the BCR three step sequential extraction procedure prior to the certification of new sediment and soil reference materials, Journal of Environmental Monitoring, 1 (1999) 57-61.\u003c/li\u003e\n\u003cli\u003eR. Yang, X.M. Xia, J.H. Wang, L.S. Zhu, J. Wang, Z. Ahmad, L.L. Yang, S.S. Mao, Y.Y. Chen, Dose and time-dependent response of single and combined artificial contamination of sulfamethazine and copper on soil enzymatic activities, Chemosphere, 250 (2020) 126161.\u003c/li\u003e\n\u003cli\u003eL. Chen, Y. Jiang, C. Liang, Y. Luo, Q. Xu, C. Han, Q. Zhao, B. Sun, Competitive interaction with keystone taxa induced negative priming under biochar amendments, Microbiome, 7 (2019) 77.\u003c/li\u003e\n\u003cli\u003eX. Qi, S.Q. Xiao, X.M. Chen, I. Ali, J.L. Gou, D. Wang, B. Zhu, W.K. Zhu, R. Shang, M.W. Han, Biochar-based microbial agent reduces U and Cd accumulation in vegetables and improves rhizosphere microecology, Journal of Hazardous Materials, 436 (2022) 129147.\u003c/li\u003e\n\u003cli\u003eM. Azeem, A. Ali, P. Jeyasundar, Y.M. Li, H. Abdelrahman, A. Latif, R.H. Li, N. Basta, G. Li, S.M. Shaheen, J. Rinklebe, Z.Q. Zhang, Bone-derived biochar improved soil quality and reduced Cd and Zn phytoavailability in a multi-metal contaminated mining soil, Environmental Pollution, 277 (2021) 116800.\u003c/li\u003e\n\u003cli\u003eH.Y. Hu, H. Zhou, S.X. Zhou, Z.J. Li, C.J. Wei, Y. Yu, A.G. Hay, Fomesafen impacts bacterial communities and enzyme activities in the rhizosphere, Environmental Pollution, 253 (2019) 302-311.\u003c/li\u003e\n\u003cli\u003eR. Yang, X. Xia, J. Wang, L. Zhu, J. Wang, Z. Ahmad, L. Yang, S. Mao, Y. Chen, Dose and time-dependent response of single and combined artificial contamination of sulfamethazine and copper on soil enzymatic activities, Chemosphere, 250 (2020) 126161.\u003c/li\u003e\n\u003cli\u003eY.L. Xu, B. Seshadri, B. Sarkar, H.L. Wang, C. Rumpel, D. Sparks, M. Farrell, T. Hall, X.D. Yang, N. Bolan, Biochar modulates heavy metal toxicity and improves microbial carbon use efficiency in soil, Science of the Total Environment, 621 (2018) 148-159.\u003c/li\u003e\n\u003cli\u003eX. Li, J. Rui, Y. Mao, A. Yannarell, R. Mackie, Dynamics of the bacterial community structure in the rhizosphere of a maize cultivar, Soil Biology and Biochemistry, 68 (2014) 392-401.\u003c/li\u003e\n\u003cli\u003eB. Zhao, C. Jiao, S. Wang, D. Zhao, C. Jiang, J. Zeng, Q.L. Wu, Contrasting assembly mechanisms explain the biogeographic patterns of benthic bacterial and fungal communities on the Tibetan Plateau, Environmental Research, 214 (2022) 113836.\u003c/li\u003e\n\u003cli\u003eL.A. Hug, C.J. Castelle, K.C. Wrighton, B.C. Thomas, I. Sharon, K.R. Frischkorn, K.H. Williams, S.G. Tringe, J.F. Banfield, Community genomic analyses constrain the distribution of metabolic traits across the Chloroflexi phylum and indicate roles in sediment carbon cycling, Microbiome, 1 (2013) 22.\u003c/li\u003e\n\u003cli\u003eN. Fierer, C.L. Lauber, K.S. Ramirez, J. Zaneveld, M.A. Bradford, R. Knight, Comparative metagenomic, phylogenetic and physiological analyses of soil microbial communities across nitrogen gradients, The ISME journal, 6 (2012) 1007-1017.\u003c/li\u003e\n\u003cli\u003eZ.J. Cui, X. Zhang, H.H. Yang, L.Q. Sun, Bioremediation of heavy metal pollution utilizing composite microbial agent of Mucor circinelloides, Actinomucor sp. and Mortierella sp, Journal of Environmental Chemical Engineering, 5 (2017) 3616-3621.\u003c/li\u003e\n\u003cli\u003eZ.-L. Qu, B. Liu, Y. Ma, J. Xu, H. Sun, The response of the soil bacterial community and function to forest succession caused by forest disease, Functional Ecology, 34 (2020).\u003c/li\u003e\n\u003cli\u003eJ. Larsbrink, L.S. McKee, Bacteroidetes bacteria in the soil: Glycan acquisition, enzyme secretion, and gliding motility, in: G.M. Gadd, S. Sariaslani (Eds.) Advances in Applied Microbiology, Vol 110, 2020, pp. 63-98.\u003c/li\u003e\n\u003cli\u003eX.P. Zhang, F.Y. Bian, Z.K. Zhong, X. Gai, C.B. Yang, Deciphering the rhizosphere microbiome of a bamboo plant in response to different chromium contamination levels, Journal of Hazardous Materials, 399 (2020) 123107.\u003c/li\u003e\n\u003cli\u003eY. Chen, Y. Chen, Y. Li, Y. Wu, Z. Zeng, R. Xu, S. Wang, H. Li, J. Zhang, Changes of heavy metal fractions during co-composting of agricultural waste and river sediment with inoculation of Phanerochaete chrysosporium, Journal of Hazardous Materials, 378 (2019) 120757.\u003c/li\u003e\n\u003cli\u003eM.O. De Beeck, J. Ruytinx, M.M. Smits, J. Vangronsveld, J.V. Colpaert, F. Rineau, Belowground fungal communities in pioneer Scots pine stands growing on heavy metal polluted and non-polluted soils, Soil Biology \u0026amp; Biochemistry, 86 (2015) 58-66.\u003c/li\u003e\n\u003cli\u003eC.B. Blackwood, M.P. Waldrop, D.R. Zak, R.L. Sinsabaugh, Molecular analysis of fungal communities and laccase genes in decomposing litter reveals differences among forest types but no impact of nitrogen deposition, Environmental Microbiology, 9 (2007) 1306-1316.\u003c/li\u003e\n\u003cli\u003eD.J. Yelle, J. Ralph, F.C. Lu, K.E. Hammel, Evidence for cleavage of lignin by a brown rot basidiomycete, Environmental Microbiology, 10 (2008) 1844-1849.\u003c/li\u003e\n\u003cli\u003eN. Zhu, J. Gao, D. Liang, Y. Zhu, B. Li, H. Jin, Thermal pretreatment enhances the degradation and humification of lignocellulose by stimulating thermophilic bacteria during dairy manure composting, Bioresource Technology, 319 (2021) 124149.\u003c/li\u003e\n\u003cli\u003eJ. She, J. Wang, X. Wei, Q. Zhang, Z. Xie, J. Beiyuan, E. Xiao, X. Yang, J. Liu, Y. Zhou, T. Xiao, Y. Wang, N. Chen, D.C.W. Tsang, Survival strategies and dominant phylotypes of maize-rhizosphere microorganisms under metal(loid)s contamination, Science of The Total Environment, 774 (2021) 145143.\u003c/li\u003e\n\u003cli\u003eJ. Zhu, S. Liu, H. Wang, D. Wang, Y. Zhu, J. Wang, Y. He, Q. Zheng, X. Zhan, Microplastic particles alter wheat rhizosphere soil microbial community composition and function, Journal of Hazardous Materials, 436 (2022) 129176.\u003c/li\u003e\n\u003cli\u003eX. Hu, J. Wang, Y. Lv, X. Liu, J. Zhong, X. Cui, M. Zhang, D. Ma, X. Yan, X. Zhu, Effects of Heavy Metals/Metalloids and Soil Properties on Microbial Communities in Farmland in the Vicinity of a Metals Smelter, Frontiers in microbiology, 12 (2021) 707786.\u003c/li\u003e\n\u003cli\u003eS. Asaf, M. Numan, A.L. Khan, A. Al-Harrasi, Sphingomonas: from diversity and genomics to functional role in environmental remediation and plant growth, Critical reviews in biotechnology, 40 (2020) 138-152.\u003c/li\u003e\n\u003cli\u003eC. Liu, H. Lin, B. Li, Y. Dong, T. Yin, Responses of microbial communities and metabolic activities in the rhizosphere during phytoremediation of Cd-contaminated soil, Ecotoxicology and Environmental Safety, 202 (2020) 110958.\u003c/li\u003e\n\u003cli\u003eX.G. Zhou, X.H. Zhang, C.L. Ma, F.Z. Wu, X. Jin, F. Dini-Andreote, Z. Wei, Biochar amendment reduces cadmium uptake by stimulating cadmium-resistant PGPR in tomato rhizosphere, Chemosphere, 307 (2022) 136138.\u003c/li\u003e\n\u003cli\u003eA. Kurosawa, R. Nishioka, N. Aburai, K. Fujii, Isolation and Characterization of Basidiomycetous Yeasts Capable of Producing Phytase under Oligotrophic Conditions, Microorganisms, 10 (2022) 2182.\u003c/li\u003e\n\u003cli\u003eQ. Ning, L. Chen, Z. Jia, C. Zhang, D. Ma, F. Li, J. Zhang, D. Li, X. Han, Z. Cai, S. Huang, W. Liu, B. Zhu, Y. Li, Multiple long-term observations reveal a strategy for soil pH-dependent fertilization and fungal communities in support of agricultural production, Agriculture, Ecosystems \u0026amp; Environment, 293 (2020) 106837.\u003c/li\u003e\n\u003cli\u003eN.P. McHunu, K. Permaul, A.Y.A. Rahman, J.A. Saito, S. Singh, M. Alam, Xylanase Superproducer: Genome Sequence of a Compost-Loving Thermophilic Fungus, Thermomyces lanuginosus Strain SSBP, Genome Announcements, 1 (2013) e00388-00313.\u003c/li\u003e\n\u003cli\u003eM.C. Manna, A. Sahu, N. De, J.K. Thakur, A. Mandal, S. Bhattacharjya, A. Ghosh, M.M. Rahman, R. Naidu, U.B. Singh, R. Dakhli, M.P. Sharma, S. Misra, Novel bio-filtration method for the removal of heavy metals from municipal solid waste, Environmental Technology \u0026amp; Innovation, 17 (2020) 100619.\u003c/li\u003e\n\u003cli\u003eX. Zhou, X. Zhang, C. Ma, F. Wu, X. Jin, F. Dini-Andreote, Z. Wei, Biochar amendment reduces cadmium uptake by stimulating cadmium-resistant PGPR in tomato rhizosphere, Chemosphere, 307 (2022) 136138.\u003c/li\u003e\n\u003cli\u003eL. Zhang, S.W. Hao, Y.P. Wang, S. Lan, Q.H. Dou, Y.Z. Peng, Rapid start-up strategy of partial denitrification and microbially driven mechanism of nitrite accumulation mediated by dissolved organic matter, Bioresource Technology, 340 (2021) 125663.\u003c/li\u003e\n\u003cli\u003eA.O. Ogundeji, Y. Li, X. Liu, L. Meng, P. Sang, Y. Mu, H. Wu, Z. Ma, J. Hou, S. Li, Eggplant by grafting enhanced with biochar recruits specific microbes for disease suppression of Verticillium wilt, Applied Soil Ecology, 163 (2021) 103912.\u003c/li\u003e\n\u003cli\u003eZ.J. Kong, M.M. Wang, X.T. Shi, X.D. Wang, X.K. Zhang, L.F. Chai, D.Y. Liu, Q.R. Shen, The functions of potential intermediates and fungal communities involved in the humus formation of different materials at the thermophilic phase, Bioresource Technology, 354 (2022) 127216.\u003c/li\u003e\n\u003cli\u003eY.L. Kong, Y. Kuzyakov, Y. Ruan, J.W. Zhang, T.T. Wang, M. Wang, S.W. Guo, Q.R. Shen, N. Ling, DNA Stable-Isotope Probing Delineates Carbon Flows from Rice Residues into Soil Microbial Communities Depending on Fertilization, Applied and Environmental Microbiology, 86 (2020) e02151-02119.\u003c/li\u003e\n\u003cli\u003eM. Baćmaga, J. Wyszkowska, J. Kucharski, Bioaugmentation of Soil Contaminated with Azoxystrobin, Water, Air, \u0026amp; Soil Pollution, 228 (2016) 19.\u003c/li\u003e\n\u003cli\u003eA. Bourceret, A. Cebron, E. Tisserant, P. Poupin, P. Bauda, T. Beguiristain, C. Leyval, The Bacterial and Fungal Diversity of an Aged PAH- and Heavy Metal-Contaminated Soil is Affected by Plant Cover and Edaphic Parameters, Microbial Ecology, 71 (2016) 711-724.\u003c/li\u003e\n\u003cli\u003eF. Luo, J.X. Zhong, Y.F. Yang, R.H. Scheuermann, J.Z. Zhou, Application of random matrix theory to biological networks, Physics Letters A, 357 (2006) 420-423.\u003c/li\u003e\n\u003cli\u003eJ. Raes, P. Bork, Systems microbiology - Timeline - Molecular eco-systems biology: towards an understanding of community function, Nature Reviews Microbiology, 6 (2008) 693-699.\u003c/li\u003e\n\u003cli\u003eM. Wang, S. Chen, L. Chen, D. Wang, Responses of soil microbial communities and their network interactions to saline-alkaline stress in Cd-contaminated soils, Environmental Pollution, 252 (2019) 1609-1621.\u003c/li\u003e\n\u003cli\u003eX.Q. Li, D.L. Meng, J. Li, H.Q. Yin, H.W. Liu, X.D. Liu, C. Cheng, Y.H. Xiao, Z.H. Liu, M.L. Yan, Response of soil microbial communities and microbial interactions to long-term heavy metal contamination, Environmental Pollution, 231 (2017) 908-917.\u003c/li\u003e\n\u003cli\u003eK. Fan, P. Weisenhorn, J.A. Gilbert, H. Chu, Wheat rhizosphere harbors a less complex and more stable microbial co-occurrence pattern than bulk soil, Soil Biology and Biochemistry, 125 (2018) 251-260.\u003c/li\u003e\n\u003cli\u003eX.M. Zhang, B.D. Chen, R.B. Yin, S.P. Xing, W. Fu, H. Wu, Z.P. Hao, Y.B. Ma, X. Zhang, Long-term nickel contamination increased soil fungal diversity and altered fungal community structure and co-occurrence patterns in agricultural soils, Journal of Hazardous Materials, 436 (2022) 129113.\u003c/li\u003e\n\u003cli\u003eB. Lalinsk\u0026aacute;-Volekov\u0026aacute;, H. Majerov\u0026aacute;, I. Kautmanov\u0026aacute;, O. Bracht\u0026yacute;r, D. Szab\u0026oacute;ov\u0026aacute;, D. Arendt, J. Brčekov\u0026aacute;, P. \u0026Scaron;ottn\u0026iacute;k, Hydrous ferric oxides (HFO\u0026apos;s) precipitated from contaminated waters at several abandoned Sb deposits \u0026ndash; Interdisciplinary assessment, Science of The Total Environment, 821 (2022) 153248.\u003c/li\u003e\n\u003cli\u003eB. Liu, J. Yao, B. Ma, Z.H. Chen, C.C. Zhao, X.Z. Zhu, M.M. Li, Y. Cao, W.C. Pang, H. Li, L.Y. Feng, V.G. Mihucz, R. Duran, Microbial community profiles in soils adjacent to mining and smelting areas: Contrasting potentially toxic metals and co-occurrence patterns, Chemosphere, 282 (2021) 130992.\u003c/li\u003e\n\u003cli\u003eR. Logares, E.S. Lindstr\u0026ouml;m, S. Langenheder, J.B. Logue, H. Paterson, J. Laybourn-Parry, K. Rengefors, L. Tranvik, S. Bertilsson, Biogeography of bacterial communities exposed to progressive long-term environmental change, The ISME journal, 7 (2013) 937-948.\u003c/li\u003e\n\u003cli\u003eL. Luan, C. Liang, L.J. Chen, H.T. Wang, Q.S. Xu, Y.J. Jiang, B. Sun, Coupling Bacterial Community Assembly to Microbial Metabolism across Soil Profiles, Msystems, 5 (2020) e00298-00220.\u003c/li\u003e\n\u003cli\u003eW.D. Chen, K.X. Ren, A. Isabwe, H.H. Chen, M. Liu, J. Yang, Stochastic processes shape microeukaryotic community assembly in a subtropical river across wet and dry seasons (vol 7, 138, 2019), Microbiome, 7 (2019) 148.\u003c/li\u003e\n\u003cli\u003eN.C. Dove, N. Tas, S.C. Hart, Ecological and genomic responses of soil microbiomes to high-severity wildfire: linking community assembly to functional potential, Isme Journal, 16 (2022) 1853-1863.\u003c/li\u003e\n\u003cli\u003eE.R. Hunting, M.G. Vijver, H.G. van der Geest, C. Mulder, M.H.S. Kraak, A.M. Breure, W. Admiraal, Resource niche overlap promotes stability of bacterial community metabolism in experimental microcosms, Frontiers in microbiology, 6 (2015) 105.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"environmental-geochemistry-and-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"egah","sideBox":"Learn more about [Environmental Geochemistry and Health](https://www.springer.com/journal/10653)","snPcode":"10653","submissionUrl":"https://submission.nature.com/new-submission/10653/3","title":"Environmental Geochemistry and Health","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Heavy Metals, Multi-Metal Contaminated Soil, Simultaneous Stabilization, Leaching Toxicity, Ecological Effects","lastPublishedDoi":"10.21203/rs.3.rs-8576852/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8576852/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eSoil heavy metal pollution, especially multi-metal contamination, is a serious environmental challenge. Stabilization has become a practical method to reduce pollution while maintaining soil ecological functions. In this study, functional materials (FMPs) composed of Fe/Mn (hydro)oxides and phosphate minerals were prepared by optimizing the molar ratio of Fe(II), Fe(III), Mn(II), and PO\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e3\u0026minus;\u003c/sup\u003e. Contaminated topsoil from a mining area was used to simulate real-world conditions. After 60 days of FMPs application at 5 wt.%, DTPA-extractable Cd, Pb, Cu, and Zn levels were reduced by 70.10%, 99.82%, 68.30% and 75.05%, respectively, meeting stabilization standards (HJ 1282\u0026ndash;2023). Notably, FMPs promoted the conversion of Cd, Pb, Cu, and Zn from labile (F1/F2) to stable (F3/F4) fractions. Additionally, FMPs significantly increased soil pH, EC, TP, AP, and NH\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e+\u003c/sup\u003e-N, while enhancing S_ACP, S_CL, and S_CAT activities, but lowered Eh, NO\u003csub\u003e3\u003c/sub\u003e\u003csup\u003e\u0026minus;\u003c/sup\u003e-N, AK, and S_UE activity. Microbial community analysis showed that FMPs changed soil microbial communities, decreasing bacterial diversity and richness (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05), but increasing fungal diversity and richness (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Molecular ecological networks indicated stronger bacterial connections and simpler fungal networks, with low-abundance taxa playing crucial ecological roles. These results underscore the effectiveness and environmental sustainability of FMPs for remediation of multi-metal contaminated soils.\u003c/p\u003e","manuscriptTitle":"Synergistic Stabilization and Ecological Restoration in Multi-Metal Contaminated Soil: The Efficacy of Fe/Mn (Hydr)oxide-Phosphate Composites (FMPs) for Cd, Pb, Cu, Zn","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-23 15:02:17","doi":"10.21203/rs.3.rs-8576852/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-05-14T12:02:05+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-29T07:06:27+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-08T10:28:17+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"232022501084516326564476154006101849659","date":"2026-04-07T14:17:52+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-11T13:42:19+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"339080772940404276248962469730473723607","date":"2026-02-24T09:38:14+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"174993540641372536811576164540056057990","date":"2026-02-23T20:49:16+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-01-22T02:45:08+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-01-12T19:10:29+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-01-12T08:20:31+00:00","index":"","fulltext":""},{"type":"submitted","content":"Environmental Geochemistry and Health","date":"2026-01-12T03:19:33+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"environmental-geochemistry-and-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"egah","sideBox":"Learn more about [Environmental Geochemistry and Health](https://www.springer.com/journal/10653)","snPcode":"10653","submissionUrl":"https://submission.nature.com/new-submission/10653/3","title":"Environmental Geochemistry and Health","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"e7157799-4311-46b3-b3bc-b993fd910724","owner":[],"postedDate":"January 23rd, 2026","published":true,"recentEditorialEvents":[{"type":"decision","content":"Revision requested","date":"2026-05-14T12:02:05+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"in-revision","subjectAreas":[],"tags":[],"updatedAt":"2026-05-14T12:10:20+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-23 15:02:17","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8576852","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8576852","identity":"rs-8576852","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}