Effects of biochar combined with MgO desulfurization waste residue on nitrogen conversion and odour emission in chicken manure composting

Effects of biochar combined with MgO desulfurization waste residue on nitrogen conversion and odour emission in chicken manure composting | 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 Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Effects of biochar combined with MgO desulfurization waste residue on nitrogen conversion and odour emission in chicken manure composting Yuwan Pang, Feng Zhen, Dehan Wang, Zifeng Luo, Jianfeng Huang, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-2250000/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Aim Chicken manure can readily produce much odour during aerobic composting. This odour pollutes the surrounding environment and represents the loss of nutrients such as nitrogen and sulfur, which reduces the fertilizer quality. Methods In this paper, biochar combined with MgO desulfurization waste residue (MDWR) was used as a new composting additive. Through composting tests, characterization analysis and pot experiments, the effect of additives in compost on nitrogen retention and deodorization was studied, the mechanism of in situ chemical deodorization was revealed, and the compost quality was verified. Results The results indicated that biochar and MDWR addition optimally reduced ammonia volatilization in chicken manure compost, and the reduction rate reached 60.12%. Volatile organic compound (VOC) emissions originating from chicken manure compost containing biochar and MDWR decreased by 44.63% compared to those originating from the control group. Conclusions The total nitrogen (TN) in the composting product containing chicken manure treated with both biochar and MDWR (CMB) was 67.7% higher than that in the composting product under the blankcontral, and this value was significantly higher than that under the other treatments and better reflected the synergistic effect of these two additives on nitrogen retention. Struvite crystals could be formed in the CMB treatment. According to the pot experiment results in terms of compost products, the CMB treatment increased the yield and quality of vegetables and reduced the nitrate content. Therefore, MDWR significantly affects nitrogen retention and deodorization of chicken manure compost while improving the compost quality; therefore, MDWR exhibits broad application prospects. chicken manure compost biochar MgO desulfurization waste residue nitrogen conversion deodorization Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Introduction Over the past 30 years, with the continuous development of China's large-scale livestock breeding industry, the arbitrary discharge of large amounts of livestock and poultry manure has seriously harmed the ecological environment (Bai et al. 2017 ;Wang et al.2017; Yang et al.2017). Livestock and poultry manure contain much organic matter and numerous nutrient elements and can provide crops with the required nutrients (Bai et al. 2016 ). Therefore, the use of livestock and poultry manure as fertilizer provides dual significance in regard to environmental protection and resource reuse. Aerobic composting exhibits the advantages of rapid degradation of organic matter, high degree of harmlessness, and high biological activity of the composting product. This technique is currently the most widely used fertilizer treatment technology for livestock and poultry waste (Bernal et al. 2009 ). However, aerobic composting is often influenced by factors such as the material ratio, composting conditions, lack of deodorization, and low deodorization efficiency, resulting in substantial nitrogen loss, reduced compost quality, and high odour production during composting (Amon et al. 2006 ;Fukumoto et al. 2006 ). Relevant studies have indicated that uneven aeration and mixing during composting could lead to local anaerobism and could produce nitrogen oxides (NOx). Ammonia volatilization under high-pH and high-temperature conditions and compost leachate loss could result in nitrogen loss. Moreover, nitrogen loss in the form of ammonia volatilization accounts for 46.8%-77.4% of the TN loss of compost (Barrington et al. 2002 ;Martins et al. 1992), severely limiting the application and promotion of aerobic composting technology (Lin et al. 2017 ). Therefore, simultaneously reducing nitrogen loss and mitigating odour in the composting process is the main research focus and a key point of composting. Biochar is a highly aromatic and stable carbonized solid material formed via pyrolysis of various biomasses under anaerobic conditions (Zhang et al. 2013;Marris et al. 2006, 12). In recent years, biochar has been increasingly used in composting. Studies have found that biochar addition could reduce ammonia volatilization and other organic volatile component emissions during composting (Chowdhury et al. 2014 ;Steiner et al. 2010 , 14). The main reason for this phenomenon is that biochar exhibits a porous structure and functional groups on the surface, thus increasing the number of cation exchange sites and microporosity. In addition, the specific surface area is high, and biochar can strongly adsorb ammonia (Agyarko-Mintah et al. 2017 ;Wei et al. 2017 ) . Scholars (Ren et al. 2010 ;Wang et al. 2013 ) have studied the application of the magnesium ammonium phosphate (MAP) precipitation method in composting. In this method, Mg 2+ is added to the composting pile and reacts with NH 4 + , PO 4 3− , HPO 4 2− , and H 2 PO 4 − , which are continuously produced in the composting process, to generate MgNH 4 PO 4 ·6H 2 O precipitates. This reaction can fix free NH 4 + , thereby reducing ammonia volatilization. Yu Y. et al. (2008) added magnesium chloride to pig manure compost and found that ammonia volatilization was 58% lower than that under the control treatment. The TN in the compost product was 18% higher than that under the control treatment, and the addition of magnesium chloride reduced the proportion of soluble phosphorus. Ren et al. ( 2009 ) added magnesium hydroxide to pig manure and straw compost. The results revealed that the ammonium nitrogen (NH 3 -N) in the treatment group was 2 times higher than that in the control group, and the TN increased by 10 g/kg. The addition of magnesium salt could significantly reduce ammonia volatilization during composting, thereby reducing air pollution and nitrogen loss. However, the magnesium salts traditionally added to compost are pure chemicals such as magnesium chloride (Jenog et al. 2001), magnesium hydroxide (Ren et al. 2010 ), and magnesium sulfate (Jiang et al. 2016 ), which are costly and difficult to activate. MgO desulfurization waste residue (MDWR) is a byproduct of wet desulfurization using magnesium oxide. The main component of MDWR is magnesium sulfite, although it is accompanied by a certain proportion of magnesium sulfate (Luo et al. 2019 ). The material is slightly soluble in water, but its direct dissolution and use are difficult. At present, the main treatment and disposal method for MDWR in China is landfill disposal, which causes not only secondary pollution but also notable resource wasting. Lin et al. ( 2017 ) determined that when added to cow manure during aerobic composting, MDWR could fix nitrogen in a manner similar to that of magnesium sulfate. The ammonia nitrogen concentration was up to 77.11% higher than that in the control group, and the nitrogen fixation rate reached 19.51%. This result indicates that using MDWR instead of magnesium sulfate as a nitrogen fixer in compost could provide high environmental and economic benefits. However, the magnesium sulfite component in MDWR creates an acidic environment in the oxidation process, which does not facilitate MAP precipitation. Therefore, we investigated whether the basicity of biochar can balance the acidity of MDWR. We also determined whether the ammonia adsorbed by biochar can produce MAP with Mg 2+ in MDWR, thereby improving the MAP crystallization efficiency. This study used the composting test method to evaluate the synergy between biochar and MDWR during in situ deodorization of chicken manure compost. During aerobic composting, biochar adsorption combined with MAP crystallization precipitation was used to improve the nitrogen retention and deodorization efficiencies. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to analyse and reveal the physical and chemical mechanisms of in situ deodorization. Finally, a pot experiment was conducted to evaluate the fertilizer efficiency of the compost products obtained from the different treatments. The main purposes of this study were to increase the efficiency of nitrogen retention and deodorization via biochar addition combined with aerobic composting, reduce process costs, improve the product fertilizer efficiency, and provide technical support for composting companies in the development of in situ deodorization technology, thus increasing the application prospects of this technology. Materials And Methods 1.1 Experimental materials Chicken manure as aerobic composting material was obtained from the chicken breeding test site of the Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Tianhe District, Guangzhou, and mushroom residue was obtained from Guangzhou Wende Agricultural Technology Co., Ltd. The obtained mushroom residue was used to increase the C/N ratio of chicken manure. The fundamental physical and chemical properties are listed in Table SM1. MDWR was acquired from a power plant in Dongguan, Guangdong, and ground into 100-mesh material. The collected MDWR mainly contained MgSO 3 and MgSO 4 , and the MgSO 3 content reached 35.7%. The heavy metal content in this material was far lower than the organic fertilizer industry standard (NY525-2012). The fundamental properties of MDWR are provided in Table SM2. Preparation of biochar: Citrus branches were dried and crushed into small pieces with a diameter smaller than 0.5 cm and a length smaller than 2 cm. The particles were rinsed with deionized water, air dried, placed in a constant-temperature drying oven at 105°C for 2 hours, added to a crucible and weighed. The mixture was placed in a nitrogen-filled atmosphere furnace and pyrolysed at a constant temperature of 325°C for 2 hours (not including the heating time). After natural cooling to room temperature in an atmospheric furnace, the sample was removed, weighed, pulverized, and passed through 40-mesh and 100-mesh sieves for use. The basic physical and chemical properties of biochar are summarized in Table SM3 and Fig. SM1. 1.2 Experimental methods 1.2.1 Study of the different compost treatments The employed composting reactor was a horizontal tank-shaped device with an insulating layer on the outside and an effective volume of 50 L. A temperature probe was placed in the reactor to regularly record the reactor temperature. With an automatic ventilation device, ventilation was applied for 5 minutes at 2-hour intervals in this experiment; involving an automatic stirring system, the device was set to stir once a day for 10 minutes each time. All programs were automatically controlled after establishment via a power line communication (PLC) system (Fig. SM2). Four compost treatments were designed in this experiment: chicken manure (CC), chicken manure + MDWR (CM), chicken manure + biochar (CB), and chicken manure + MDWR + biochar (CMB). Chicken manure and mushroom residue were mixed at a ratio of 1:1, the C/N ratio was adjusted to 25:1, and the moisture content ranged from 50%. The addition ratio of biochar and MDWR was approximately 8% of the weight of the dry material. MDWR was first dried, pulverized through a 20-mesh sieve, mixed with biochar and added to the treatment compost. In the composting process, pH, NH 3 -N, nitrate nitrogen (NO 3 -N), TN, and total sulfur sampling and analysis were performed on days 1, 3, 7, 14, 21, 28, and 35. Starting on the 3rd day, gas was collected every day for 13 minutes. The absorption solutions adopted included a 1% sodium hydroxide solution and 2% boric acid solution (2 drops of nitrogen indicator were added). These solutions were added to a 250-mL Erlenmeyer flask to determine the ammonia and hydrogen sulfide contents. Volatile organic compounds (VOCs) were determined via gas chromatography–mass spectrometry (GC–MS). 1.2.2 Form and composition analysis of the compost products The air-dried compost samples were further dried at 55°C for 2 hours and passed through a 40-mesh sieve for use. Microstructural analysis was conducted via gold sputter coating and SEM (model: S-3700N, Hitachi High-tech Corporation); the crystal structure was analysed via XRD (model: D8ADVANCE, Bruker, Germany). 1.2.3 Effects of the finished compost products on the vegetable yield and quality The pot experiment was designed with 4 treatments, namely, CC, CB, CM, and CMB. The amount of soil per pot was 8.5 kg, the organic fertilizer amount accounted for 2.5% of the soil dry weight, and the fertilizer amount added was the amount needed to achieve 0.2 g N/kg soil, 0.07 g P 2 O 5 /kg soil, and 0.14 g K 2 O/kg soil. Lettuce was cultivated for 45 days during one season, and the plant yield and quality were determined. 1.2.4 Analytical methods All sample parameters were measured according to corresponding national standards. TN was determined via the Kjeldahl nitrogen distillation method; the total sulfur content was obtained via the turbidimetric method; NH 3 -N and NO 3 -N were determined via the potassium chloride extraction colorimetric method; and the pH was measured with a PHS-3C precision pH meter. The ammonia and hydrogen sulfide levels were measured via the dilute sulfuric acid back titration method. With the use of GC–MS, at a temperature ranging from 20–24°C and a relative humidity ranging from 50–60%, the gas in the sampling bag was adsorbed onto an adsorption fibre, the adsorption fibre underwent desorption in the injection port, and the main gas composition was analysed and compared to the NIST05a library (JISK0123-2006). The experimental data were analysed in SPSS 20.0 software, and Origin 9.0 was used to generate graphs. Results And Discussion 1.3 Nitrogen retention and deodorization effects of biochar combined with MDWR 1.3.1 Effect of temperature and pH changes As shown in Fig. 1 , the CB treatment temperature increased the fastest, reaching the high-temperature stage (50°C) in 2 days. The CC and CMB treatments entered the high-temperature stage on the third day, while the CM treatment reached the high-temperature stage on the fourth day. This result indicates that MDWR addition affected the fermentation efficiency at the initial stage, but biochar addition weakened this effect and shortened the delayed heating period due to MDWR addition. The highest temperatures under the four treatments, i.e., CC, CB, CM, and CMB, were 62.8, 64.8, 60.4, and 62.6°C, respectively. Regarding safety, each treatment completely met the sanitary requirements of China’s faecal harmlessness standards (GB 7959 − 2012). The pH is a key indicator affecting the microbial activity in compost [24]. The initial compost pH was 8.6 (CC). As shown in Fig. 1 , at the initial composting stage, due to the degradation of small molecular organic substances to generate organic acids and carbon dioxide and MDWR addition under the CM treatment, the pH under the CC and CM treatments decreased over time. The CB and CMB treatments contained biochar, which provided a suitable buffering effect. With regular aeration in the aerobic composting process, carbon dioxide was discharged from the pile. With increasing compost temperature, some protein was degraded to produce NH 3 , and the pH of the pile gradually increased. The trends were relatively consistent among the various treatments. Since SO 3 2− in MDWR was gradually converted into SO 4 2− , thereby increasing the acidity during composting, the pH under the CM treatment was low and decreased to 7.99 by the end of the composting process, which could increase ammonia volatilization inhibition. Biochar addition under the CMB treatment resulted in the smallest change in pH among all treatments, at only 0.31 units. This could not only alleviate the problem of high product acidity likely caused by MDWR acidification but could also adsorb the generated ammonia in the composting process. By the 14th day, the pH under each treatment reached its maximum value. From day 21 (the late composting period), the pH under all treatments except the CB treatment decreased synchronously, and at the end of composting, the pH values under the four treatments were 8.37, 8.44, 7.99 and 8.16. The acidification effect under the two treatments involving MDWR was obvious, and the difference was significant compared to the acidity under the CC treatment according to the multiple comparison test method (P < 0.05). 1.3.2 Effect of changes in NH 3 -N, NO 3 -N and TN Ammonia volatilization is the main form of nitrogen loss during composting (Delaune et al. 2004 ). As shown in Fig. 2 , the overall trend in NH 3 -N under each treatment first increased, then decreased, and then stabilized. On the 4th day, the NH 3 -N under the CM treatment began to decline and then stabilized, indicating that MDWR addition resulted in effective nitrogen nutrient retention in the system. Under the CMB treatment, NH 3 -N stably declined from the 7th day, mainly attributable to MDWR addition. Some NH 3 -N formed MAP, but the remainder, accounting for a large proportion, was adsorbed onto biochar. However, the ammonia nitrogen content under the CC and CD treatments without MDWR addition began to rapidly decline from 14–15 days. This phenomenon occurred for two reasons: one reason was that nitrification began to increase; the other reason was that the proportion of nitrogenous organic substances that could be degraded by microorganisms decreased. At the end of composting, the NH 3 -N concentrations under the CC, CB, CM, and CMB treatments were 4.05, 4.21, 6.82, and 6.71 g/kg, respectively. After correlation analysis, the difference between the CM and CMB treatments and CC and CB treatments, i.e., the treatments with and without MDWR addition, respectively, was significant (p < 0.05), indicating that MDWR addition significantly influenced NH 3 -N content enhancement in the compost pile. As shown in Fig. 2 , except under the CMB treatment, the NO 3 -Na under the other three treatments hardly increased over the first 7 days. During the high-temperature period, the increase in NO 3 -N was limited. However, starting from the 14th day, as the pile temperature gradually decreased, nitrification began to increase, and the NO 3 -N content rapidly increased. The NO 3 -N under the CM and CMB treatments indicated that MDWR addition did not affect the activity of nitrifying bacteria. In contrast, when the reactor pH was lowered and the NH 3 -N increased, the NO 3 -N under the CM and CMB treatments was significantly higher than that under the CC and CB treatments. At the end of composting, the NO 3 -N concentrations under the four treatments, i.e., CC, CB, CM, and CMB, were 21.22, 23.31, 25.42, and 26.02 g/kg, respectively. The TN in organic fertilizer is an important index to measure its quality (Ouatmane et al. 2000 ). At the early composting stage, due to organic matter decomposition, the loss of carbon and dry matter occurred faster than that of nitrogen, resulting in a continuous increase in the TN of each treated sample (Cerda et al. 2018 ). As shown in Fig. 2 , the TN in each treated sample first increased and then decreased. Due to MDWR addition, the fermentation process under the CM and CMB treatments slowly progressed, while that under the CC and CB treatments rapidly progressed. The first increase in the TN was reached on the 3rd day of composting. After the start of the continuous high-temperature period on the 3rd day, much ammonia was volatilized, so the TN in each treated sample decreased to varying degrees. Because other nitrogen conservation measures were not implemented, the TN under the CC treatment rapidly decreased, reaching 3.51% and 12.07% on the 7th and 14th days, respectively. However, the TN under the CB, CM, and CMB treatments decreased by 2.29%, 5.76%, and 2.89%, respectively, on the 14th day. These three treatments yielded ideal nitrogen retention effects during the high-temperature period of the composting process. At the middle and late composting stages (14–28 days), the nitrification process in the pile was relatively intense, ammonia volatilization was reduced, and TN reduction decreased, whereas that under the CM and CMB treatments increased. During ageing (28–35 days), the TN under the four treatments slightly increased due to the influence of comprehensive factors, such as a decrease in the reactor temperature, improved biochar adsorption, increased MAP formation and enhanced nitrification. At this point, organic matter decomposition continued, increasing the ratio of TN to the dry matter mass. By the end of composting on the 35th day, the TN loss ratios under the CC, CB, CM, and CMB treatments reached 39.9%, 36.9%, 28.9%, and 17.2%, respectively. After multiple comparative analysis, the differences between the treatments were significant (p < 0.05). In contrast to the CB and CM treatments, the CMB treatment exhibited the ideal synergistic behaviour between biochar and MDWR. 1.3.3 Effect of changes in ammonia, hydrogen sulfide and VOC emissions In this study, we monitored the ammonia emission dynamics of each treated sample from the 3rd day because the daily emissions of each sample were very low beyond the 12th day. Therefore, the dynamic tracking time in this experiment ranged from 3–14 days. As shown in Fig. 3 -a, from days 3–8, the highest ammonia emissions were observed under the CC treatment (22.99 g/kg); the second-largest amount was observed under the CB treatment (15.93 g/kg). The sample under the CB treatment produced the highest cumulative emissions from days 9–11 (6.7 g/kg); the sample under the CM treatment exhibited the highest cumulative emissions from days 12–14 (1.88 g/kg). Since the pH of the sample under the CM treatment with MDWR always remained low, ammonia volatilization could be controlled. In addition, magnesium salt could form MAP with ammonia and phosphate so that the ammonia concentration in the reactor was relatively low, which was also a factor of ammonia volatilization reduction. Ammonia volatilization always remained low under the CMB treatment involving the addition of both MDWR and biochar, reflecting the synergy between these two additives and indicating that this measure could optimally suppress ammonia volatilization in compost. During the 12-day monitoring period, the cumulative ammonia volatilization amounts under the four treatments, i.e., CC, CB, CM, and CMB, were 27.13, 23.56, 13.32, and 10.82 g/kg, respectively. The CMB treatment, which exhibited the best effect, reduced the cumulative ammonia volatilization amount by 60.12%. After correlation analysis, the differences between the four treatments were significant (P < 0.05). Hydrogen sulfide, another typical odorous inorganic molecule involved in the composting process, has attracted much attention due to its low odour threshold and notable harmfulness. As shown in Fig. 3 -b, due to MDWR addition under the CM and CMB treatments, the hydrogen sulfide emissions were significantly higher than those under the CC and CB treatments, and the cumulative emissions at 12 days reached 121.9 and 112.2 g/kg, respectively. This result indicated that biochar addition could reduce hydrogen sulfide emissions to a certain extent. From this perspective, when MDWR is used as a nitrogen-retaining agent during composting, it is necessary to implement and study related supporting technologies to reduce hydrogen sulfide emissions and prevent secondary pollution attributed to this technology. VOCs not only cause environmental pollution but also cause respiratory, endocrine, circulatory and nervous system damage in humans and animals and may seriously endanger the health of industrial workers and residents. Therefore, composting companies must consider VOC emissions. Table 1 indicates that the different treatments exhibited notable differences in the corresponding control effects for the various types of gases emitted. Among the 16 VOCs above the detection limit, 8 were not controlled by one or several measures designed in this experiment, indicating that VOC control during composting entails a relatively complicated process. From an overall VOC control perspective, the CB, CM, and CMB treatments yielded notable effects, with VOC emissions reduced by 27.17%, 41.67%, and 44.63%, respectively, compared to those under the CC treatment. Among the 8 controlled odorous gases in China, dimethyl disulfide and styrene were measured via GC–MS. Under the CB, CM, and CMB treatments, dimethyl disulfide emissions were reduced by 30.42%, 54.34% and 55.27%, respectively, indicating optimal emission reduction effects of biochar and MDWR addition. However, styrene emissions remained unaffected. In contrast, the CM and CMB treatments achieved notable improvement. The deodorization measures in this experiment did not reduce styrene and other VOC emissions, and further research is needed. Table 1 Volatile organic compound emissions under the different treatments during the high-temperature composting period (V/V %) Items Component CC CB CM CMB 1 Dimethyl sulfide 6.13 5.63 8.78 7.25 2 Dimethyl disulfide 56.77 39.5 25.92 25.39 3 Dimethyl trisulfide 7.12 5.93 4.51 4.15 4 Dimethyl tetrasulfide 0.18 0.23 0.12 0.11 5 S-methyl 3-methylbutanethioate 0.37 0.18 0.07 0 6 2-Methylpyrazine 0.31 0.19 0.21 0.18 7 2-Heptanone 0.41 0.3 0.61 0.64 8 Styrene 0.41 0.41 0.72 0.81 9 Cyclohexanone 1.12 1.11 1.27 1.43 10 1,3-Dithiane 0.35 0.25 0.22 0.29 11 2-Ethylhexanol 1.3 1.08 1.4 1.33 12 2-Nonanone 0.22 0.22 0.39 0.37 13 N-dodecane 0.12 0.11 0.13 0.15 14 2,6-Dimethylphenol 0.01 0.01 0.02 0.02 15 N-capronitrile 0.21 0.12 0 0 16 2,6-Lutidine 1.04 0.13 0 0 Total 76.07 55.40 44.37 42.12 1.4 Research on the deodorization mechanism of biochar combined with MDWR 1.4.1 SEM–EDS analysis of the crystals formed in the compost As shown in Fig. 4 , SEM was used to observe the crystals formed in the compost under 500× magnification, and we could observe that there existed obvious distributions of flake-, X- and Y-shaped rhomboid crystals. These structures are typical of MAP. The relative content of elements was obtained via SEM-energy dispersive spectroscopy (EDS) (Table SM4). The relative content ratio between nitrogen, magnesium, and phosphorus was 1:1.24:0.77, indicating that the crystals were not pure MAP (NH 4 MgPO 4 ). The reason for this ratio may be the poor solubility of MDWR, which was mixed into MAP during crystallization, introducing impurities; additionally, it was confirmed that nitrogen under the MDWR and biochar treatments was partially converted into MAP as a slow-release nitrogen fertilizer to achieve nitrogen retention. 1.4.2 X-ray diffraction pattern of the crystals formed in the compost The XRD pattern shown in Fig. 5 reveals that the diffraction angle was very close to the standard angle of MAP crystals, which proves that the crystals comprised MAP, but the purity was lower than that of standard MAP crystals. Some nitrogen in the composting process was converted into MAP slow-release nitrogen fertilizer, which further proves that magnesium residue and biochar could retain nitrogen as composting additives in chicken manure compost. 1.5 Effects of the composting products on the vegetable yield and quality 1.5.1 Effects of the different treatments on the vegetable yield The pot experiment results demonstrated that the change in yield under each lettuce treatment was basically the same (Table 2 ). When the two compost product treatments, CB and CMB, which contained biochar, were applied, the lettuce yield was higher than that under the other treatments, but there was no significant difference in the yield between the two treatments (P < 0.05). Among them, the treatment with the highest yield was the CB treatment. The yield under this treatment reached 783.5 g/3 plants. Compared to the control treatment, CC, the yield increased by 7.3%. There was no significant difference in the lettuce yield between the CMB and CM treatments involving compost treated with MDWR (P < 0.05). Table 2 Effect of the different treatments on the lettuce yield Treatments Yield (g/3 plants) CC 730.0 ± 20.61c CB 783.5 ± 25.93ab CM 747.0 ± 38.21bc CMB 779.9 ± 48.23ab 1.5.2 Effects of the different treatments on the vegetable quality According to the pot experiment results, the vitamin C content in the plants under the CB and CMB treatments did not significantly differ from that under the CC control, and the treatment yielding the lowest content was the CMB treatment (145.8 mg/kg). The vitamin C content under the CM treatment was significantly higher than that under the CC, CB and CMB treatments, and the content was 212.4 mg/kg. Regarding the soluble sugar content, the content under the CM and CMB treatments was significantly higher than that under the other treatments (P < 0.05), and the contents were 25.7 and 24.4 g/kg, respectively. The treatment providing the highest nitrate content was the CC treatment (943.0 mg/kg), followed by the CM treatment, with a nitrate content of 894.3 mg/kg. The nitrate content under the CB and CMB treatment, both involving biochar, was significantly lower than that under the remaining treatments (P < 0.05) (Fig. 6 -b). The treatment generating the lowest content was the CB treatment, with a content of 726.1 mg/kg. Conclusion The combined treatment of chicken manure compost with biochar and MDWR could significantly improve ammonia removal, reduce dimethyl disulfide volatilization, and significantly deodorize samples, reflecting ideal synergistic conditions, but a small amount of hydrogen sulfide was still emitted. The chemical mechanism of in situ deodorization of the new compost additive MDWR was preliminarily clarified. The product was analysed via SEM and XRD to identify MAP crystals, indicating that MDWR could replace other soluble magnesium salts and could be used as a compost additive. Finally, the pot experiment confirmed that the new compost additive could improve both the vegetable quality and yield. Declarations Author contributions Yuwan Pang : formal analysis, data curation, writing—original draft, and writing—review and editing. Jianfeng Huang : conceptualization, methodology, resources, and supervision. Feng Zhen, Dehan Wang : investigation. Zifeng Luo : visualization. Yanli Zhang : validation. All authors read and approved the final manuscript. Funding This study was financially supported by the National Key Research and the Guangzhou Municipal People’s Livelihood Science and Technology Project (201903010085) and the Agricultural Advantage Industry Discipline Team Construction Project of Guangdong Academy of Agricultural Sciences (202121TD). C ompeting interests 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. Data availability The data and materials used and/or analyzed during the current study are available from the corresponding author on reasonable request. Ethics approval and consent to participate Not applicable . Consent for publication Not applicable. References Agyarko-Mintah E, Cowie A, Zwieten LV, Singh BP, Smillie R, Harden S, Fornasier F (2017): Biochar lowers ammonia emission and improves nitrogen retention in poultry litter composting. Waste Management 61, 129-137 Amon B, Kryvoruchko V, Amon T, Zechmeister-Boltenstern S (2006): Methane, nitrous oxide and ammonia emissions during storage and after application of dairy cattle slurry and influence of slurry treatment - ScienceDirect. 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Nature 442, 624-626 Ouatmane A, Provenzano MR, Hafidi M, Senesi N (2000): Compost Maturity Assessment Using Calorimetry, Spectroscopy and Chemical Analysis. Compost Science & Utilization 8, 124-134 Ren LM, Li GX, Shen YJ, Li CP, Guo R (2009): Application of struvite crystallization on co-composting of swine manure and cornstalk. Huan Jing Ke Xue 30, 2165-2173 Ren L, Schuchardt F, Shen Y, Li G, Li C (2010): Impact of struvite crystallization on nitrogen losses during composting of pig manure and cornstalk. Waste Management 30, 885-892 Steiner C, Das KC, Melear N, Lakly D (2010): Reducing nitrogen loss during poultry litter composting using biochar. Journal of Environmental Quality 39, 1236-1242 Wei C, Liao X, Wu Y, Liang JB, Mi J, Huang J, Zhang H, Yu W, Qiao Z, Xi L (2017): Effects of different types of biochar on methane and ammonia mitigation during layer manure composting. Waste Management 61, 506-515 Wang X, Selvam A, Chan M, Wong J (2013): Nitrogen conservation and acidity control during food wastes composting through struvite formation. Bioresource Technology 147, 17-22 Wang H, Xu J, Liu X, Sheng L, Zhang D, Li L, Wang A (2017): Study on the pollution status and control measures for the livestock and poultry breeding industry in northeastern China. Environmental Science and Pollution Research 25, 4435-4445 Yang X, Li Q, Tang Z, Zhang W, Yu G, Shen Q, Zhao FJ (2017): Heavy metal concentrations and arsenic speciation in animal manure composts in China. Waste Management, 333 Yu Y, Yuansong W, L J (2008): Effect of Magnesium Salt Addition on Nutrients Conservation During Swine Manure Composting. Huan Jing Ke Xue 29, 2672-2677 Zheng H, Wang Z, Deng X, Herbert S, Xing B (2013): Impacts of adding biochar on nitrogen retention and bioavailability in agricultural soil. Geoderma 206, 32-39 Supplementary Files Graphicabstract.docx SUPPLEMENTARYMATERIAL.docx Cite Share Download PDF Status: Posted Version 1 posted 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 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-2250000","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":171329577,"identity":"b86774cc-48b7-489e-8d21-149059e967bf","order_by":0,"name":"Yuwan Pang","email":"","orcid":"","institution":"Guangdong Academy of Agricultural Sciences","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Yuwan","middleName":"","lastName":"Pang","suffix":""},{"id":171329578,"identity":"c1dbfdf9-c9a0-47c8-abba-0830b3e99a2d","order_by":1,"name":"Feng Zhen","email":"","orcid":"","institution":"Guangzhou Institute of Energy Conversion","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Feng","middleName":"","lastName":"Zhen","suffix":""},{"id":171329579,"identity":"a04e1e88-8ae1-45cd-9c95-7c778307af1a","order_by":2,"name":"Dehan Wang","email":"","orcid":"","institution":"South China Agricultural University College of Natural Resources and the Environment","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Dehan","middleName":"","lastName":"Wang","suffix":""},{"id":171329580,"identity":"b978b5d0-5538-41be-beb1-ad0ba567e235","order_by":3,"name":"Zifeng Luo","email":"","orcid":"","institution":"South China Agricultural University College of Natural Resources and the Environment","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Zifeng","middleName":"","lastName":"Luo","suffix":""},{"id":171329581,"identity":"1e510bad-2780-4913-b6cc-6392486a2c3e","order_by":4,"name":"Jianfeng Huang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6klEQVRIie3PsWrDMBCA4TMCdzmjVaalfYUDg43B0Fc5CHhKIaNHh4AzlHb2Y+QRlAgyKXT1kCFevDbd0iUkGbvYHgPVN53gfjgBOM4dIli3B6Yzypfv61BkYxIT0bHQT2E5FXSw+ZhExGFtdUbl1A/bajOcJJ6Bx6DaI8FuW7CvQS7fuTdJSwNRUHWYeJ95w7gHZXer/sP0l54ElcB0AXHDqgNSb0OJAXNLaAvxjMmMSrx5bQ2SxRiYxyUCjkWOYe1PFOsch//SmIcTU/YqlVj//J6zZ7n86E9A6b9v7F+/keXwjuM4zj93AUXtUcU3n/4qAAAAAElFTkSuQmCC","orcid":"","institution":"Guangdong Academy of Agricultural Sciences","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Jianfeng","middleName":"","lastName":"Huang","suffix":""},{"id":171329582,"identity":"229785fb-7c7a-41ff-83d2-b5a2fcb6fbef","order_by":5,"name":"Yanli Zhang","email":"","orcid":"","institution":"Mudanjiang Normal University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Yanli","middleName":"","lastName":"Zhang","suffix":""}],"badges":[],"createdAt":"2022-11-08 08:28:42","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-2250000/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-2250000/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":32291254,"identity":"5060ee71-dd59-4479-b764-66332b610b6a","added_by":"auto","created_at":"2023-01-31 20:17:03","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":64433,"visible":true,"origin":"","legend":"\u003cp\u003eChanges in the temperature and pH during composting\u003c/p\u003e\n\u003cp\u003eNotes: a pH; b temperature\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-2250000/v1/d2683145b9713123169d78b0.jpg"},{"id":32291261,"identity":"7833c41c-7acb-4854-b4a7-0502b709660d","added_by":"auto","created_at":"2023-01-31 20:17:03","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":75097,"visible":true,"origin":"","legend":"\u003cp\u003eChanges in ammonium nitrogen, nitrate nitrogen and total nitrogen in compost\u003c/p\u003e\n\u003cp\u003eNotes: a Ammonium nitrogen; b nitrate nitrogen; c total nitrogen\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-2250000/v1/9221b60bf26680ee98b2debb.jpg"},{"id":32291255,"identity":"9f82e16a-2fa6-43d3-b89e-87c06249873d","added_by":"auto","created_at":"2023-01-31 20:17:03","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":68610,"visible":true,"origin":"","legend":"\u003cp\u003eDynamic conditions of ammonia (a) and hydrogen sulfide (b) emissions during the high-temperature composting period\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-2250000/v1/3a9ee656e98e1dfeba168d1c.jpg"},{"id":32292567,"identity":"65abfc9f-314d-4e9f-8dee-de727728064f","added_by":"auto","created_at":"2023-01-31 20:41:03","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":68644,"visible":true,"origin":"","legend":"\u003cp\u003eSEM images and EDS spectra of the compost products\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-2250000/v1/16477b7702e180f3f8168a56.jpg"},{"id":32291412,"identity":"5ea0cbca-d9c9-47d2-9222-1432244e2d3f","added_by":"auto","created_at":"2023-01-31 20:25:03","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":45521,"visible":true,"origin":"","legend":"\u003cp\u003eXRD spectra of the crystals in the compost\u003c/p\u003e","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-2250000/v1/3bec9f89ae4d64b94e9b5f2a.jpg"},{"id":32293269,"identity":"0f4987f1-7b10-475b-bac4-b8a3d46d14f4","added_by":"auto","created_at":"2023-01-31 20:49:03","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":75317,"visible":true,"origin":"","legend":"\u003cp\u003eEffect of the different treatments on the quality of lettuce\u003c/p\u003e\n\u003cp\u003eNote: a Vitamin C and soluble sugars; b nitrates\u003c/p\u003e","description":"","filename":"6.jpg","url":"https://assets-eu.researchsquare.com/files/rs-2250000/v1/fc5b97193bdb3cfe728a2a7a.jpg"},{"id":36977723,"identity":"920782b5-4b70-4709-a759-88abe968efb1","added_by":"auto","created_at":"2023-05-13 00:23:36","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":738512,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-2250000/v1/286a68c0-253e-495a-b0b0-f44ef2aa5878.pdf"},{"id":32291864,"identity":"7419e674-681f-42e3-89e3-4516dd5c82d8","added_by":"auto","created_at":"2023-01-31 20:33:03","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":385443,"visible":true,"origin":"","legend":"","description":"","filename":"Graphicabstract.docx","url":"https://assets-eu.researchsquare.com/files/rs-2250000/v1/cc47aec7eb779ce962fe9ab2.docx"},{"id":32291259,"identity":"9b43865f-3287-4099-bf82-95b16e453143","added_by":"auto","created_at":"2023-01-31 20:17:03","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":180362,"visible":true,"origin":"","legend":"","description":"","filename":"SUPPLEMENTARYMATERIAL.docx","url":"https://assets-eu.researchsquare.com/files/rs-2250000/v1/dbfb0c4ed16a0a6dabeb7c6c.docx"}],"financialInterests":"","formattedTitle":"Effects of biochar combined with MgO desulfurization waste residue on nitrogen conversion and odour emission in chicken manure composting","fulltext":[{"header":"Introduction","content":"\u003cp\u003eOver the past 30 years, with the continuous development of China's large-scale livestock breeding industry, the arbitrary discharge of large amounts of livestock and poultry manure has seriously harmed the ecological environment (Bai et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2017\u003c/span\u003e;Wang et al.2017; Yang et al.2017). Livestock and poultry manure contain much organic matter and numerous nutrient elements and can provide crops with the required nutrients (Bai et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). Therefore, the use of livestock and poultry manure as fertilizer provides dual significance in regard to environmental protection and resource reuse.\u003c/p\u003e \u003cp\u003eAerobic composting exhibits the advantages of rapid degradation of organic matter, high degree of harmlessness, and high biological activity of the composting product. This technique is currently the most widely used fertilizer treatment technology for livestock and poultry waste (Bernal et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). However, aerobic composting is often influenced by factors such as the material ratio, composting conditions, lack of deodorization, and low deodorization efficiency, resulting in substantial nitrogen loss, reduced compost quality, and high odour production during composting (Amon et al. \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2006\u003c/span\u003e;Fukumoto et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2006\u003c/span\u003e). Relevant studies have indicated that uneven aeration and mixing during composting could lead to local anaerobism and could produce nitrogen oxides (NOx). Ammonia volatilization under high-pH and high-temperature conditions and compost leachate loss could result in nitrogen loss. Moreover, nitrogen loss in the form of ammonia volatilization accounts for 46.8%-77.4% of the TN loss of compost (Barrington et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2002\u003c/span\u003e;Martins et al. 1992), severely limiting the application and promotion of aerobic composting technology (Lin et al. \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). Therefore, simultaneously reducing nitrogen loss and mitigating odour in the composting process is the main research focus and a key point of composting.\u003c/p\u003e \u003cp\u003eBiochar is a highly aromatic and stable carbonized solid material formed via pyrolysis of various biomasses under anaerobic conditions (Zhang et al. 2013;Marris et al. 2006, 12). In recent years, biochar has been increasingly used in composting. Studies have found that biochar addition could reduce ammonia volatilization and other organic volatile component emissions during composting (Chowdhury et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2014\u003c/span\u003e;Steiner et al. \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2010\u003c/span\u003e, 14). The main reason for this phenomenon is that biochar exhibits a porous structure and functional groups on the surface, thus increasing the number of cation exchange sites and microporosity. In addition, the specific surface area is high, and biochar can strongly adsorb ammonia (Agyarko-Mintah et al. \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2017\u003c/span\u003e;Wei et al. \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2017\u003c/span\u003e) .\u003c/p\u003e \u003cp\u003eScholars (Ren et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2010\u003c/span\u003e;Wang et al. \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2013\u003c/span\u003e) have studied the application of the magnesium ammonium phosphate (MAP) precipitation method in composting. In this method, Mg\u003csup\u003e2+\u003c/sup\u003e is added to the composting pile and reacts with NH\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e+\u003c/sup\u003e, PO\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e3\u0026minus;\u003c/sup\u003e, HPO\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e2\u0026minus;\u003c/sup\u003e, and H\u003csub\u003e2\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e\u0026minus;\u003c/sup\u003e, which are continuously produced in the composting process, to generate MgNH\u003csub\u003e4\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e\u0026middot;6H\u003csub\u003e2\u003c/sub\u003eO precipitates. This reaction can fix free NH\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e+\u003c/sup\u003e, thereby reducing ammonia volatilization. Yu Y. et al. (2008) added magnesium chloride to pig manure compost and found that ammonia volatilization was 58% lower than that under the control treatment. The TN in the compost product was 18% higher than that under the control treatment, and the addition of magnesium chloride reduced the proportion of soluble phosphorus. Ren et al. (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2009\u003c/span\u003e) added magnesium hydroxide to pig manure and straw compost. The results revealed that the ammonium nitrogen (NH\u003csub\u003e3\u003c/sub\u003e-N) in the treatment group was 2 times higher than that in the control group, and the TN increased by 10 g/kg. The addition of magnesium salt could significantly reduce ammonia volatilization during composting, thereby reducing air pollution and nitrogen loss. However, the magnesium salts traditionally added to compost are pure chemicals such as magnesium chloride (Jenog et al. 2001), magnesium hydroxide (Ren et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2010\u003c/span\u003e), and magnesium sulfate (Jiang et al. \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2016\u003c/span\u003e), which are costly and difficult to activate. MgO desulfurization waste residue (MDWR) is a byproduct of wet desulfurization using magnesium oxide. The main component of MDWR is magnesium sulfite, although it is accompanied by a certain proportion of magnesium sulfate (Luo et al. \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). The material is slightly soluble in water, but its direct dissolution and use are difficult. At present, the main treatment and disposal method for MDWR in China is landfill disposal, which causes not only secondary pollution but also notable resource wasting. Lin et al. (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2017\u003c/span\u003e) determined that when added to cow manure during aerobic composting, MDWR could fix nitrogen in a manner similar to that of magnesium sulfate. The ammonia nitrogen concentration was up to 77.11% higher than that in the control group, and the nitrogen fixation rate reached 19.51%. This result indicates that using MDWR instead of magnesium sulfate as a nitrogen fixer in compost could provide high environmental and economic benefits. However, the magnesium sulfite component in MDWR creates an acidic environment in the oxidation process, which does not facilitate MAP precipitation. Therefore, we investigated whether the basicity of biochar can balance the acidity of MDWR. We also determined whether the ammonia adsorbed by biochar can produce MAP with Mg\u003csup\u003e2+\u003c/sup\u003e in MDWR, thereby improving the MAP crystallization efficiency.\u003c/p\u003e \u003cp\u003eThis study used the composting test method to evaluate the synergy between biochar and MDWR during in situ deodorization of chicken manure compost. During aerobic composting, biochar adsorption combined with MAP crystallization precipitation was used to improve the nitrogen retention and deodorization efficiencies. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to analyse and reveal the physical and chemical mechanisms of in situ deodorization. Finally, a pot experiment was conducted to evaluate the fertilizer efficiency of the compost products obtained from the different treatments. The main purposes of this study were to increase the efficiency of nitrogen retention and deodorization via biochar addition combined with aerobic composting, reduce process costs, improve the product fertilizer efficiency, and provide technical support for composting companies in the development of in situ deodorization technology, thus increasing the application prospects of this technology.\u003c/p\u003e"},{"header":"Materials And Methods","content":"\u003cp\u003e\u003cspan style=\"text-align: inherit;\"\u003e\u003cstrong\u003e1.1 Experimental materials\u003c/strong\u003e\u003c/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eChicken manure as aerobic composting material was obtained from the chicken breeding test site of the Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Tianhe District, Guangzhou, and mushroom residue was obtained from Guangzhou Wende Agricultural Technology Co., Ltd. The obtained mushroom residue was used to increase the C/N ratio of chicken manure. The fundamental physical and chemical properties are listed in Table SM1.\u003c/p\u003e\n\u003cp\u003eMDWR was acquired from a power plant in Dongguan, Guangdong, and ground into 100-mesh material. The collected MDWR mainly contained MgSO\u003csub\u003e3\u003c/sub\u003e and MgSO\u003csub\u003e4\u003c/sub\u003e, and the MgSO\u003csub\u003e3\u003c/sub\u003e content reached 35.7%. The heavy metal content in this material was far lower than the organic fertilizer industry standard (NY525-2012). The fundamental properties of MDWR are provided in Table SM2.\u003c/p\u003e\n\u003cp\u003ePreparation of biochar: Citrus branches were dried and crushed into small pieces with a diameter smaller than 0.5 cm and a length smaller than 2 cm. The particles were rinsed with deionized water, air dried, placed in a constant-temperature drying oven at 105\u0026deg;C for 2 hours, added to a crucible and weighed. The mixture was placed in a nitrogen-filled atmosphere furnace and pyrolysed at a constant temperature of 325\u0026deg;C for 2 hours (not including the heating time). After natural cooling to room temperature in an atmospheric furnace, the sample was removed, weighed, pulverized, and passed through 40-mesh and 100-mesh sieves for use. The basic physical and chemical properties of biochar are summarized in Table SM3 and Fig. SM1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.2 Experimental methods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.2.1 Study of the different compost treatments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe employed composting reactor was a horizontal tank-shaped device with an insulating layer on the outside and an effective volume of 50 L. A temperature probe was placed in the reactor to regularly record the reactor temperature. With an automatic ventilation device, ventilation was applied for 5 minutes at 2-hour intervals in this experiment; involving an automatic stirring system, the device was set to stir once a day for 10 minutes each time. All programs were automatically controlled after establishment via a power line communication (PLC) system (Fig. SM2).\u003c/p\u003e\n\u003cp\u003eFour compost treatments were designed in this experiment: chicken manure (CC), chicken manure\u0026thinsp;+\u0026thinsp;MDWR (CM), chicken manure\u0026thinsp;+\u0026thinsp;biochar (CB), and chicken manure\u0026thinsp;+\u0026thinsp;MDWR\u0026thinsp;+\u0026thinsp;biochar (CMB). Chicken manure and mushroom residue were mixed at a ratio of 1:1, the C/N ratio was adjusted to 25:1, and the moisture content ranged from 50%. The addition ratio of biochar and MDWR was approximately 8% of the weight of the dry material. MDWR was first dried, pulverized through a 20-mesh sieve, mixed with biochar and added to the treatment compost. In the composting process, pH, NH\u003csub\u003e3\u003c/sub\u003e-N, nitrate nitrogen (NO\u003csub\u003e3\u003c/sub\u003e-N), TN, and total sulfur sampling and analysis were performed on days 1, 3, 7, 14, 21, 28, and 35. Starting on the 3rd day, gas was collected every day for 13 minutes. The absorption solutions adopted included a 1% sodium hydroxide solution and 2% boric acid solution (2 drops of nitrogen indicator were added). These solutions were added to a 250-mL Erlenmeyer flask to determine the ammonia and hydrogen sulfide contents. Volatile organic compounds (VOCs) were determined via gas chromatography\u0026ndash;mass spectrometry (GC\u0026ndash;MS).\u003c/p\u003e\n\u003cp\u003e\u003cspan style=\"text-align: inherit;\"\u003e\u003cstrong\u003e1.2.2 Form and composition analysis of the compost products\u003c/strong\u003e\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003eThe air-dried compost samples were further dried at 55\u0026deg;C for 2 hours and passed through a 40-mesh sieve for use. Microstructural analysis was conducted via gold sputter coating and SEM (model: S-3700N, Hitachi High-tech Corporation); the crystal structure was analysed via XRD (model: D8ADVANCE, Bruker, Germany).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.2.3 Effects of the finished compost products on the vegetable yield and quality\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe pot experiment was designed with 4 treatments, namely, CC, CB, CM, and CMB. The amount of soil per pot was 8.5 kg, the organic fertilizer amount accounted for 2.5% of the soil dry weight, and the fertilizer amount added was the amount needed to achieve 0.2 g N/kg soil, 0.07 g P\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e/kg soil, and 0.14 g K\u003csub\u003e2\u003c/sub\u003eO/kg soil. Lettuce was cultivated for 45 days during one season, and the plant yield and quality were determined.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.2.4 Analytical methods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll sample parameters were measured according to corresponding national standards. TN was determined via the Kjeldahl nitrogen distillation method; the total sulfur content was obtained via the turbidimetric method; NH\u003csub\u003e3\u003c/sub\u003e-N and NO\u003csub\u003e3\u003c/sub\u003e-N were determined via the potassium chloride extraction colorimetric method; and the pH was measured with a PHS-3C precision pH meter. The ammonia and hydrogen sulfide levels were measured via the dilute sulfuric acid back titration method. With the use of GC\u0026ndash;MS, at a temperature ranging from 20\u0026ndash;24\u0026deg;C and a relative humidity ranging from 50\u0026ndash;60%, the gas in the sampling bag was adsorbed onto an adsorption fibre, the adsorption fibre underwent desorption in the injection port, and the main gas composition was analysed and compared to the NIST05a library (JISK0123-2006).\u003c/p\u003e\n\u003cp\u003eThe experimental data were analysed in SPSS 20.0 software, and Origin 9.0 was used to generate graphs.\u003c/p\u003e"},{"header":"Results And Discussion","content":"\u003cp\u003e\u003cstrong\u003e1.3 Nitrogen retention and deodorization effects of biochar combined with MDWR\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.3.1 Effect of temperature and pH changes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAs shown in Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e, the CB treatment temperature increased the fastest, reaching the high-temperature stage (50\u0026deg;C) in 2 days. The CC and CMB treatments entered the high-temperature stage on the third day, while the CM treatment reached the high-temperature stage on the fourth day. This result indicates that MDWR addition affected the fermentation efficiency at the initial stage, but biochar addition weakened this effect and shortened the delayed heating period due to MDWR addition. The highest temperatures under the four treatments, i.e., CC, CB, CM, and CMB, were 62.8, 64.8, 60.4, and 62.6\u0026deg;C, respectively. Regarding safety, each treatment completely met the sanitary requirements of China\u0026rsquo;s faecal harmlessness standards (GB 7959\u0026thinsp;\u0026minus;\u0026thinsp;2012).\u003c/p\u003e\n\u003cp\u003eThe pH is a key indicator affecting the microbial activity in compost [24]. The initial compost pH was 8.6 (CC). As shown in Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e, at the initial composting stage, due to the degradation of small molecular organic substances to generate organic acids and carbon dioxide and MDWR addition under the CM treatment, the pH under the CC and CM treatments decreased over time. The CB and CMB treatments contained biochar, which provided a suitable buffering effect. With regular aeration in the aerobic composting process, carbon dioxide was discharged from the pile. With increasing compost temperature, some protein was degraded to produce NH\u003csub\u003e3\u003c/sub\u003e, and the pH of the pile gradually increased. The trends were relatively consistent among the various treatments. Since SO\u003csub\u003e3\u003c/sub\u003e\u003csup\u003e2\u0026minus;\u003c/sup\u003e in MDWR was gradually converted into SO\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e2\u0026minus;\u003c/sup\u003e, thereby increasing the acidity during composting, the pH under the CM treatment was low and decreased to 7.99 by the end of the composting process, which could increase ammonia volatilization inhibition. Biochar addition under the CMB treatment resulted in the smallest change in pH among all treatments, at only 0.31 units. This could not only alleviate the problem of high product acidity likely caused by MDWR acidification but could also adsorb the generated ammonia in the composting process. By the 14th day, the pH under each treatment reached its maximum value. From day 21 (the late composting period), the pH under all treatments except the CB treatment decreased synchronously, and at the end of composting, the pH values under the four treatments were 8.37, 8.44, 7.99 and 8.16. The acidification effect under the two treatments involving MDWR was obvious, and the difference was significant compared to the acidity under the CC treatment according to the multiple comparison test method (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.3.2 Effect of changes in NH\u003csub\u003e3\u003c/sub\u003e-N, NO\u003csub\u003e3\u003c/sub\u003e-N and TN\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAmmonia volatilization is the main form of nitrogen loss during composting (Delaune et al. \u003cspan class=\"CitationRef\"\u003e2004\u003c/span\u003e). As shown in Fig. \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e, the overall trend in NH\u003csub\u003e3\u003c/sub\u003e-N under each treatment first increased, then decreased, and then stabilized. On the 4th day, the NH\u003csub\u003e3\u003c/sub\u003e-N under the CM treatment began to decline and then stabilized, indicating that MDWR addition resulted in effective nitrogen nutrient retention in the system. Under the CMB treatment, NH\u003csub\u003e3\u003c/sub\u003e-N stably declined from the 7th day, mainly attributable to MDWR addition. Some NH\u003csub\u003e3\u003c/sub\u003e-N formed MAP, but the remainder, accounting for a large proportion, was adsorbed onto biochar. However, the ammonia nitrogen content under the CC and CD treatments without MDWR addition began to rapidly decline from 14\u0026ndash;15 days. This phenomenon occurred for two reasons: one reason was that nitrification began to increase; the other reason was that the proportion of nitrogenous organic substances that could be degraded by microorganisms decreased. At the end of composting, the NH\u003csub\u003e3\u003c/sub\u003e-N concentrations under the CC, CB, CM, and CMB treatments were 4.05, 4.21, 6.82, and 6.71 g/kg, respectively. After correlation analysis, the difference between the CM and CMB treatments and CC and CB treatments, i.e., the treatments with and without MDWR addition, respectively, was significant (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05), indicating that MDWR addition significantly influenced NH\u003csub\u003e3\u003c/sub\u003e-N content enhancement in the compost pile.\u003c/p\u003e\n\u003cp\u003eAs shown in Fig. \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e, except under the CMB treatment, the NO\u003csub\u003e3\u003c/sub\u003e-Na under the other three treatments hardly increased over the first 7 days. During the high-temperature period, the increase in NO\u003csub\u003e3\u003c/sub\u003e-N was limited. However, starting from the 14th day, as the pile temperature gradually decreased, nitrification began to increase, and the NO\u003csub\u003e3\u003c/sub\u003e-N content rapidly increased. The NO\u003csub\u003e3\u003c/sub\u003e-N under the CM and CMB treatments indicated that MDWR addition did not affect the activity of nitrifying bacteria. In contrast, when the reactor pH was lowered and the NH\u003csub\u003e3\u003c/sub\u003e-N increased, the NO\u003csub\u003e3\u003c/sub\u003e-N under the CM and CMB treatments was significantly higher than that under the CC and CB treatments. At the end of composting, the NO\u003csub\u003e3\u003c/sub\u003e-N concentrations under the four treatments, i.e., CC, CB, CM, and CMB, were 21.22, 23.31, 25.42, and 26.02 g/kg, respectively.\u003c/p\u003e\n\u003cp\u003eThe TN in organic fertilizer is an important index to measure its quality (Ouatmane et al. \u003cspan class=\"CitationRef\"\u003e2000\u003c/span\u003e). At the early composting stage, due to organic matter decomposition, the loss of carbon and dry matter occurred faster than that of nitrogen, resulting in a continuous increase in the TN of each treated sample (Cerda et al. \u003cspan class=\"CitationRef\"\u003e2018\u003c/span\u003e). As shown in Fig. \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e, the TN in each treated sample first increased and then decreased. Due to MDWR addition, the fermentation process under the CM and CMB treatments slowly progressed, while that under the CC and CB treatments rapidly progressed. The first increase in the TN was reached on the 3rd day of composting. After the start of the continuous high-temperature period on the 3rd day, much ammonia was volatilized, so the TN in each treated sample decreased to varying degrees. Because other nitrogen conservation measures were not implemented, the TN under the CC treatment rapidly decreased, reaching 3.51% and 12.07% on the 7th and 14th days, respectively. However, the TN under the CB, CM, and CMB treatments decreased by 2.29%, 5.76%, and 2.89%, respectively, on the 14th day. These three treatments yielded ideal nitrogen retention effects during the high-temperature period of the composting process. At the middle and late composting stages (14\u0026ndash;28 days), the nitrification process in the pile was relatively intense, ammonia volatilization was reduced, and TN reduction decreased, whereas that under the CM and CMB treatments increased. During ageing (28\u0026ndash;35 days), the TN under the four treatments slightly increased due to the influence of comprehensive factors, such as a decrease in the reactor temperature, improved biochar adsorption, increased MAP formation and enhanced nitrification. At this point, organic matter decomposition continued, increasing the ratio of TN to the dry matter mass. By the end of composting on the 35th day, the TN loss ratios under the CC, CB, CM, and CMB treatments reached 39.9%, 36.9%, 28.9%, and 17.2%, respectively. After multiple comparative analysis, the differences between the treatments were significant (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). In contrast to the CB and CM treatments, the CMB treatment exhibited the ideal synergistic behaviour between biochar and MDWR.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.3.3 Effect of changes in ammonia, hydrogen sulfide and VOC emissions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn this study, we monitored the ammonia emission dynamics of each treated sample from the 3rd day because the daily emissions of each sample were very low beyond the 12th day. Therefore, the dynamic tracking time in this experiment ranged from 3\u0026ndash;14 days. As shown in Fig. \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e-a, from days 3\u0026ndash;8, the highest ammonia emissions were observed under the CC treatment (22.99 g/kg); the second-largest amount was observed under the CB treatment (15.93 g/kg). The sample under the CB treatment produced the highest cumulative emissions from days 9\u0026ndash;11 (6.7 g/kg); the sample under the CM treatment exhibited the highest cumulative emissions from days 12\u0026ndash;14 (1.88 g/kg). Since the pH of the sample under the CM treatment with MDWR always remained low, ammonia volatilization could be controlled. In addition, magnesium salt could form MAP with ammonia and phosphate so that the ammonia concentration in the reactor was relatively low, which was also a factor of ammonia volatilization reduction. Ammonia volatilization always remained low under the CMB treatment involving the addition of both MDWR and biochar, reflecting the synergy between these two additives and indicating that this measure could optimally suppress ammonia volatilization in compost. During the 12-day monitoring period, the cumulative ammonia volatilization amounts under the four treatments, i.e., CC, CB, CM, and CMB, were 27.13, 23.56, 13.32, and 10.82 g/kg, respectively. The CMB treatment, which exhibited the best effect, reduced the cumulative ammonia volatilization amount by 60.12%. After correlation analysis, the differences between the four treatments were significant (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/p\u003e\n\u003cp\u003eHydrogen sulfide, another typical odorous inorganic molecule involved in the composting process, has attracted much attention due to its low odour threshold and notable harmfulness. As shown in Fig. \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e-b, due to MDWR addition under the CM and CMB treatments, the hydrogen sulfide emissions were significantly higher than those under the CC and CB treatments, and the cumulative emissions at 12 days reached 121.9 and 112.2 g/kg, respectively. This result indicated that biochar addition could reduce hydrogen sulfide emissions to a certain extent. From this perspective, when MDWR is used as a nitrogen-retaining agent during composting, it is necessary to implement and study related supporting technologies to reduce hydrogen sulfide emissions and prevent secondary pollution attributed to this technology.\u003c/p\u003e\n\u003cp\u003eVOCs not only cause environmental pollution but also cause respiratory, endocrine, circulatory and nervous system damage in humans and animals and may seriously endanger the health of industrial workers and residents. Therefore, composting companies must consider VOC emissions. Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e indicates that the different treatments exhibited notable differences in the corresponding control effects for the various types of gases emitted. Among the 16 VOCs above the detection limit, 8 were not controlled by one or several measures designed in this experiment, indicating that VOC control during composting entails a relatively complicated process. From an overall VOC control perspective, the CB, CM, and CMB treatments yielded notable effects, with VOC emissions reduced by 27.17%, 41.67%, and 44.63%, respectively, compared to those under the CC treatment. Among the 8 controlled odorous gases in China, dimethyl disulfide and styrene were measured via GC\u0026ndash;MS. Under the CB, CM, and CMB treatments, dimethyl disulfide emissions were reduced by 30.42%, 54.34% and 55.27%, respectively, indicating optimal emission reduction effects of biochar and MDWR addition. However, styrene emissions remained unaffected. In contrast, the CM and CMB treatments achieved notable improvement. The deodorization measures in this experiment did not reduce styrene and other VOC emissions, and further research is needed.\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n \u003ctable border=\"1\" id=\"Tab1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eVolatile organic compound emissions under the different treatments during the high-temperature composting period (V/V %)\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eItems\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eComponent\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCC\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCB\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCM\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCMB\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDimethyl sulfide\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8.78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7.25\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDimethyl disulfide\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e56.77\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e39.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e25.92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e25.39\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDimethyl trisulfide\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.93\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.51\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.15\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDimethyl tetrasulfide\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.11\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eS-methyl 3-methylbutanethioate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.37\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2-Methylpyrazine\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.18\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2-Heptanone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.41\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.64\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eStyrene\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.41\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.41\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.72\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.81\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCyclohexanone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.43\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1,3-Dithiane\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.29\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2-Ethylhexanol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.33\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2-Nonanone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.37\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eN-dodecane\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.15\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2,6-Dimethylphenol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.02\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eN-capronitrile\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2,6-Lutidine\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eTotal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e76.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e55.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e44.37\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e42.12\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.4 Research on the deodorization mechanism of biochar combined with MDWR\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.4.1 SEM\u0026ndash;EDS analysis of the crystals formed in the compost\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAs shown in Fig. \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e, SEM was used to observe the crystals formed in the compost under 500\u0026times; magnification, and we could observe that there existed obvious distributions of flake-, X- and Y-shaped rhomboid crystals. These structures are typical of MAP. The relative content of elements was obtained via SEM-energy dispersive spectroscopy (EDS) (Table SM4). The relative content ratio between nitrogen, magnesium, and phosphorus was 1:1.24:0.77, indicating that the crystals were not pure MAP (NH\u003csub\u003e4\u003c/sub\u003eMgPO\u003csub\u003e4\u003c/sub\u003e). The reason for this ratio may be the poor solubility of MDWR, which was mixed into MAP during crystallization, introducing impurities; additionally, it was confirmed that nitrogen under the MDWR and biochar treatments was partially converted into MAP as a slow-release nitrogen fertilizer to achieve nitrogen retention.\u003c/p\u003e\n\u003cp\u003e\u003cspan style=\"text-align: inherit;\"\u003e\u003cstrong\u003e1.4.2 X-ray diffraction pattern of the crystals formed in the compost\u003c/strong\u003e\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003eThe XRD pattern shown in Fig. \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e reveals that the diffraction angle was very close to the standard angle of MAP crystals, which proves that the crystals comprised MAP, but the purity was lower than that of standard MAP crystals. Some nitrogen in the composting process was converted into MAP slow-release nitrogen fertilizer, which further proves that magnesium residue and biochar could retain nitrogen as composting additives in chicken manure compost.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.5 Effects of the composting products on the vegetable yield and quality\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.5.1 Effects of the different treatments on the vegetable yield\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe pot experiment results demonstrated that the change in yield under each lettuce treatment was basically the same (Table \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). When the two compost product treatments, CB and CMB, which contained biochar, were applied, the lettuce yield was higher than that under the other treatments, but there was no significant difference in the yield between the two treatments (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Among them, the treatment with the highest yield was the CB treatment. The yield under this treatment reached 783.5 g/3 plants. Compared to the control treatment, CC, the yield increased by 7.3%. There was no significant difference in the lettuce yield between the CMB and CM treatments involving compost treated with MDWR (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n \u003ctable border=\"1\" id=\"Tab2\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eEffect of the different treatments on the lettuce yield\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eTreatments\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eYield (g/3 plants)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e730.0\u0026thinsp;\u0026plusmn;\u0026thinsp;20.61c\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCB\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e783.5\u0026thinsp;\u0026plusmn;\u0026thinsp;25.93ab\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e747.0\u0026thinsp;\u0026plusmn;\u0026thinsp;38.21bc\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCMB\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e779.9\u0026thinsp;\u0026plusmn;\u0026thinsp;48.23ab\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003e1.5.2 Effects of the different treatments on the vegetable quality\u003c/strong\u003e\u003cbr\u003e\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003eAccording to the pot experiment results, the vitamin C content in the plants under the CB and CMB treatments did not significantly differ from that under the CC control, and the treatment yielding the lowest content was the CMB treatment (145.8 mg/kg). The vitamin C content under the CM treatment was significantly higher than that under the CC, CB and CMB treatments, and the content was 212.4 mg/kg. Regarding the soluble sugar content, the content under the CM and CMB treatments was significantly higher than that under the other treatments (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05), and the contents were 25.7 and 24.4 g/kg, respectively.\u003c/p\u003e\n\u003cp\u003eThe treatment providing the highest nitrate content was the CC treatment (943.0 mg/kg), followed by the CM treatment, with a nitrate content of 894.3 mg/kg. The nitrate content under the CB and CMB treatment, both involving biochar, was significantly lower than that under the remaining treatments (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) (Fig. \u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003e-b). The treatment generating the lowest content was the CB treatment, with a content of 726.1 mg/kg.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe combined treatment of chicken manure compost with biochar and MDWR could significantly improve ammonia removal, reduce dimethyl disulfide volatilization, and significantly deodorize samples, reflecting ideal synergistic conditions, but a small amount of hydrogen sulfide was still emitted. The chemical mechanism of in situ deodorization of the new compost additive MDWR was preliminarily clarified. The product was analysed via SEM and XRD to identify MAP crystals, indicating that MDWR could replace other soluble magnesium salts and could be used as a compost additive. Finally, the pot experiment confirmed that the new compost additive could improve both the vegetable quality and yield.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eYuwan Pang\u003c/strong\u003e: formal analysis, data curation, writing\u0026mdash;original draft, and writing\u0026mdash;review and editing. \u003cstrong\u003eJianfeng Huang\u003c/strong\u003e: conceptualization, methodology, resources, and supervision. \u003cstrong\u003eFeng Zhen, Dehan Wang\u003c/strong\u003e: investigation. \u003cstrong\u003eZifeng Luo\u003c/strong\u003e: visualization. \u003cstrong\u003eYanli Zhang\u003c/strong\u003e: validation.\u0026nbsp;All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was financially supported by the National Key Research and the Guangzhou Municipal People\u0026rsquo;s Livelihood Science and Technology Project (201903010085) and the Agricultural Advantage Industry Discipline Team Construction Project of Guangdong Academy of Agricultural Sciences (202121TD).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eC\u003c/strong\u003e\u003cstrong\u003eompeting\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;interests\u003c/strong\u003e\u003c/p\u003e\n\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\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data and materials used and/or analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e Not applicable\u003cstrong\u003e.\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u0026nbsp;\u003c/strong\u003eNot applicable.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eAgyarko-Mintah E, Cowie A, Zwieten LV, Singh BP, Smillie R, Harden S, Fornasier F (2017): Biochar lowers ammonia emission and improves nitrogen retention in poultry litter composting. 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Geoderma 206, 32-39\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"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":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"chicken manure compost, biochar, MgO desulfurization waste residue, nitrogen conversion, deodorization","lastPublishedDoi":"10.21203/rs.3.rs-2250000/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-2250000/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eAim\u003c/h2\u003e \u003cp\u003eChicken manure can readily produce much odour during aerobic composting. This odour pollutes the surrounding environment and represents the loss of nutrients such as nitrogen and sulfur, which reduces the fertilizer quality.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eIn this paper, biochar combined with MgO desulfurization waste residue (MDWR) was used as a new composting additive. Through composting tests, characterization analysis and pot experiments, the effect of additives in compost on nitrogen retention and deodorization was studied, the mechanism of in situ chemical deodorization was revealed, and the compost quality was verified.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThe results indicated that biochar and MDWR addition optimally reduced ammonia volatilization in chicken manure compost, and the reduction rate reached 60.12%. Volatile organic compound (VOC) emissions originating from chicken manure compost containing biochar and MDWR decreased by 44.63% compared to those originating from the control group.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eThe total nitrogen (TN) in the composting product containing chicken manure treated with both biochar and MDWR (CMB) was 67.7% higher than that in the composting product under the blankcontral, and this value was significantly higher than that under the other treatments and better reflected the synergistic effect of these two additives on nitrogen retention. Struvite crystals could be formed in the CMB treatment. According to the pot experiment results in terms of compost products, the CMB treatment increased the yield and quality of vegetables and reduced the nitrate content. Therefore, MDWR significantly affects nitrogen retention and deodorization of chicken manure compost while improving the compost quality; therefore, MDWR exhibits broad application prospects.\u003c/p\u003e","manuscriptTitle":"Effects of biochar combined with MgO desulfurization waste residue on nitrogen conversion and odour emission in chicken manure composting","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2023-01-31 20:16:58","doi":"10.21203/rs.3.rs-2250000/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"e7a58153-b62a-4357-9e59-ff00d610925a","owner":[],"postedDate":"January 31st, 2023","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2023-05-13T00:23:24+00:00","versionOfRecord":[],"versionCreatedAt":"2023-01-31 20:16:58","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-2250000","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-2250000","identity":"rs-2250000","version":["v1"]},"buildId":"369fNeqWncA4NS6XSWjrt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}