Reactive cement pellet media including drinking water treatment and mine drainage residuals for phosphorus removal in agricultural runoff

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Holly This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6347283/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 Soil phosphorus (P) losses through agricultural runoff and tile drainage can lead to eutrophication of water resources. Drinking water treatment residual (DWTR) and acid mine drainage residual (AMD) have the ability to remove P but lack mechanical strength and a uniform particle size. Previous studies of DWTR and AMD consisted primarily of batch trials and measurement of P removal using flow-through columns, utilizing real agricultural runoff, would be beneficial to scalability. We modified DWTR and AMD through pelletization and pyrolysis and evaluated P removal using flow-through columns under different conditions (i.e. retention time, pH, and agricultural runoff). Pyrolysis increased P removal of the media pellets 2 to 17-fold. Filter media performance benefited from longer retention times and P removal efficiency increased 8-134% when retention time was increased from 1- to 5- min. Cost estimate and practicality for field deployment in a constructed pond wetland system were evaluated for each media. Cement binder + pyrolysis (CEM-P), cement binder (CEM), cement binder + DWTR + pyrolysis (RCB-P), and cement binder + AMD (ACB) were the most practical media for field deployment. The top 3 least costly media were CEM-P ( $ 1,936), cement binder + AMD + pyrolysis (ACB-P; $ 2,159), and CEM ( $ 2,809). Filter media cement binder pellet phosphorus removal agricultural runoff drinking water treatment residual acid mine drainage residual constructed wetland Figures Figure 1 Figure 2 Figure 3 Introduction Extensive nutrient loads result in harmful algal blooms in waterbodies throughout the Mississippi River basin and Great Lakes region (Kalcic et al. 2018 ). Algal blooms decay and decrease dissolved oxygen, impairing Great Lakes freshwater ecosystems (Robertson and Saad 2011 ). Agricultural operations can have a negative impact on water quality by releasing high nitrogen and phosphorus (P) loads to surface water (Kalcic et al. 2018 ). Subsurface tile drainage is an additional source of P loss (consisting of 21–68% dissolved P; Madison et al, 2014 ) from agricultural fields, routing infiltrated precipitation and nutrients to surface waters (Tanner et al. 2010 ). Constructed wetlands and sedimentation basins can be constructed to intercept sediment flow and reduce particulate-P (Sharpley et al., 2006 ). Reactive filter media incorporated within constructed wetlands may result in enhanced P removal through adsorption of dissolved P. Previously investigated reactive filter material for the removal of dissolved P can be categorized as natural, industrial by-products, and man-made (engineered) (Vohla et al. 2011 ). The ideal filter media would be a local waste material that is low cost to benefit a circular economy. Efficient media for P removal has significant mass composition of calcium (Ca), iron (Fe), and aluminum (Al), and most of the media that has been studied contains a high percent of Ca and/or CaO (Vohla et al. 2011 ). Drinking water treatment residuals (DWTR), the waste by-products from the drinking water treatment process, include common coagulants Fe or Al and can be reused as an adsorbent for P (Nguyen et al. 2022 ). The properties of DWTR depend on the source of the water being treated and the methods used to treat the water, including the type of coagulant (Ahmad et al, 2016 ). The aluminum content of DWTR from plants using aluminum coagulants is on average approximately 16% of the chemical composition by weight (Muisa et al., 2020 ). Other main components of DWTR include Ca, SiO 2 2− , Fe, Cl − , SO 4 2− , and humic acids (Nguyen et al. 2022 ). Metal oxides, capable of reacting with phosphorus, measured in DWTR include CaO, MgO, Na 2 O, K 2 O, and P 2 O 5 and some trace metals (Nguyen et al. 2022 ). Previously measured P removal capacity of aluminum based DWTR varies depending on experimental design (batch or column) and conditions (pH, particle size, initial P concentration), resulting in a large range of measured P removal capacities (2 to 43 mg P/g DWTR: Muisa et al., 2020 ). DWTR adsorption of P in DWTR amended constructed wetlands accounts for 59–75% of the dissolved P removed (Kumar et al, 2011 ). Acid mine drainage (AMD) has negative environmental impacts by containing high concentrations of dissolved metals and having a low pH (Johnson and Hallberg, 2005 ). AMD residual is the product remaining after the AMD is treated to neutralize the pH and to precipitate heavy metals and is then disposed of (Roger et al, 2006). AMD residual are rich in Fe and Al hydrated oxides (Sibrell et al, 2012). AMD residual has a high potential to be used as a sorbent for P removal from agricultural runoff (Penn et al, 2007 ) which would provide a beneficial reuse of AMD before disposal which would support a circular economy. Metal residuals, such as AMD and DWTR, lack mechanical strength, have heterogenous particle size, and low hydraulic conductivities increasing the potential clogging in filtration systems (Li et al. 2018 ). Filtration systems including constructed wetlands commonly use a media size of 5–20 mm (Vymazal and Kropfelova, 2008), uncommon for raw DWTR and AMD. Raw DWTR and AMD must be converted into a granular form with a high mechanical strength for use as a filter media in a wetland. Common technologies that have been developed to convert raw DWTR into a granular form include pelletizing and sintering (Zou et al, 2012 ), wood loading (Soleimanifar et al, 2016 ), and gel entrapment (Jung et al, 2016 ). We evaluated the use of pelletized DWTR and AMD residual to remove dissolved P from agricultural runoff through flow through bench-top laboratory studies to determine P-removal potential and removal efficiency at different pH concentrations, retention times, and effectiveness for real agricultural runoff. Bench-top flow-through trials were used to control the environment, increase replicates, study several factors, scalability, efficiency, and reduce costs. The novelty of this work is the development of a DWTR and AMD cement binder pellet, produced from a pellet mill, for the treatment of agricultural runoff. In addition, the evaluation of filter media used real agricultural runoff and representative retention times to determine flowrate for scalability. To the best of the authors' knowledge this is the first-time cement, DWTR, and AMD pellets, with and without heat treatment, were produced using a scalable method (i.e. pellet mill) for the removal of P from agricultural runoff. Materials and Methods Materials DWTR was obtained from the Green Bay Water Utility treating raw water pumped from Lake Michigan near the City of Kewaunee through ozonation, coagulation with sodium hypochlorite and polyaluminum chloride (PACl), flocculation, sedimentation, and filtration. The use of a PACl coagulant resulted in an aluminum-based drinking water treatment residual (DWTR) which was passively dewatered in a settling pond (Shown in Supplementary Information Figure S1 ). The DWTR were collected in August 2022 and April 2023 in buckets, partially dried, and sieved to < 4mm. The sieved DWTR were then dried at 105℃ for 24 hours before pelletizing. AMD residual was sourced from the Blue Valley Mine Drainage Treatment and Fish Culture Station in Camp Brandy, PA as described in Sibrell P.L., and Tucker T.W. (2012). Physical and Chemical Modification DWTR and AMD required a binder to increase mechanical strength, minimize dissolution in water, create a uniform particle size, and reduce clogging. Cement and AlCl 3 were both investigated as potential binders. While the AlCl 3 binder increased mechanical strength when dry, it lost strength upon exposure to water. Consequently, cement was used as a binder for the pellets in this study. Cement was a more effective binder than AlCl 3 as it forms stable solid hydrates when reacting with water (Naqi and Jang, 2019 ). Optimal ratios of binder (i.e. sand, lime, and cement; Shown in Supplementary Information Table S1 ) for mechanical strength were evaluated by hand rolling test balls of mixtures into spheres (2 and 4 mm) and air drying for 24 hours. Insolubility and mechanical strength were evaluated by soaking the pellets in water for 24 hours and compressing pellets by hand (Shown in Supplementary Information Table S2 ). Visible inspection and tactile evaluations were performed to determine binder type and optimal ratio for flow through analysis (Table 1 ). The optimal binder ratio that was used to create the pellets is a ratio of 1 part lime, 1 part Portland cement, and 2 parts sand. Table 1 Pellet mixture ratio for each pellet type. Pellet Type ID Pellet Mixture Ratio Cement binder (sand, lime, cement) CEM 1 Lime : 1 PC : 2 Sand Cement binder w/ pyrolysis CEM-P 1 Lime : 1 PC : 2 Sand Cement binder + DWTR RCB 1 Lime : 1 PC : 2 Sand : 2 DWTR Cement binder + DWTR w/ pyrolysis RCB-P 1 Lime : 1 PC : 2 Sand : 2 DWTR Cement binder + AMD residual ACB 1 Lime : 1 PC : 2 Sand : 2 AMD residual Cement binder + AMD residual w/ pyrolysis ACB-P 1 Lime : 1 PC : 2 Sand : 2 AMD residual Pellet mixtures were made into pellets by incorporating approximately 20% DI water by mass with a drill-powered paint mixer and pelletizing using vertical pellet mill (220 V Three Phase; PelletMasters, Chippewa Falls, Wisconsin) with a 3 mm diameter die plate. A portion of each pellet type were heat treated through pyrolysis (N 2 gas purged chamber held at 600ᵒC for 15 min) to improve P removal potential by increasing the pore size, removing organic matter, increasing metal concentrations, and oxidizing calcium carbonate. Control test pellets included a cement binder (CEM), pyrolyzed cement binder (CEM-P), cement binder + DWTR (RCB), and cement binder + AMD (ACB) to determine the impact of the cement binder, DWTR, AMD, and pyrolysis on P removal. Flow Through Columns Conventionally, batch and column experiments are both used to evaluate the removal of contaminants (Wang et al., 2009 ). Batch experiments neglect actual solid to liquid ratios and contact times from field observations, overestimating filter media removal (Wang et al., 2009 ). Column experiments, used in the current study, offer a more realistic simulation of the real environment because the contaminant travels through the pore spaces of the solid packed in the column (Wang et al., 2009 ). Flow-through experiments were evaluated in triplicate and consisted of 1.8 cm diameter PVC pipes that were 60 cm long (Fig. 1 ). Each column was loosely packed with 7.6 cm of filter media (17–25 g) and about 2 cm of glass beads on each side separated by glass wool. To determine P removal potential, filter performance over time, and exhaustion, columns received synthetic agricultural runoff at a 1-minute retention time until exhaustion (20% P removal; Fig. 2 ). A 1-minute retention time was selected as this would enable a small footprint and is representative of a short retention time ( 99% purity; Santa Cruz Biotechnology; Dallas, TX) in DI water to obtain a P concentration of 0.5 ± 0.05 mg P/L, with a pH level of 6 ± 0.6. Influent and effluent samples were collected at 4-hour intervals for the sorption capacity trials. Factors influential to phosphorus removal were also evaluated through flow through columns including retention time (i.e., 1-, 5-, and 10-min), pH (i.e. 6, 8 and 10) and real agricultural runoff were tested for each media type (Fig. 2 ). Selected retention times evaluated performance variability across a range of conditions including high and low flow rate. Real agricultural runoff trials elucidated dissolved P treatment interference from suspended solids, organic matter, and other dissolved ions in runoff. Trial flow rates to meet retention times (i.e., 1, 5, and 10 minutes) favorable of field deployment were obtained by adjusting the flow rate to 9, 1.8, and 0.9 mL/min respectively using a peristaltic pump. The flow rate was determined using Eq. 1 : $$\:Q\:=\frac{V\:\cdot\:\:{n}_{e}}{\tau\:}$$ 1 where Q is the flow rate (mL/min), V is the bulk volume of media in column (mL), n e is the effective porosity (unitless, 0.5), and τ is the hydraulic retention time (min). Collection times varied with retention time to compare trials across a uniform applied mass of P. The influent and effluent were collected every 20 hours until hour 100 for the 5-minute retention columns and every 40 hours until hour 200 for the 10-minute retention columns. The pH of the synthetic agricultural runoff was adjusted to 8 and 10 using 0.1M NaOH (> 97% purity; Acros Orgaincs; Geel, Belgium) to assess its impact on P removal, with testing conducted at a flow rate that produced a 1-minute hydraulic retention time. The influent and effluent from the pH trials were collected every 4 hours until hour 20 (10.8 L). Percent P removal was calculated from measured P in influent and effluent concentrations through Eq. 2 : $$\:R=\frac{\left({C}_{o}-{C}_{e}\right)}{{C}_{o}}\cdot\:100\%$$ 2 where R is the percent P removal, C o is the average influent concentration (mg P/L), C e is the average effluent concentration (mg P/L). The performance of the media was evaluated using the average P removal capacity (mg P/kg media) which was calculated using the following Eq. 3 : $$\:{q}_{t}={\Sigma\:}\frac{\left({C}_{o}-{C}_{e}\right)\cdot\:V}{m}$$ 3 where q t is the P removal (mg P/kg media) at 20% exhaustion or 10.8L, C 0 is the discrete influent concentration (mg P/L), C e is the effluent concentration (mg P/L), V is the volume (L) of water treated per each time point, and m is the mass (kg) of media. The performance of each filter media was compared using cumulative P removal efficiencies (Penn et al. 2017). Cumulative P removal efficiency was determined by plotting cumulative P removed (equations 4 and 5) as a function of cumulative P added (equations 4 and 5) similarly to Penn et al. (2017). The y-intercept was set to zero and the slope is equal to cumulative P removal efficiency (Penn et al. 2017). Agricultural Runoff To evaluate efficacy of P removal from real agricultural runoff, runoff was sampled from a sedimentation basin receiving agricultural runoff in Kaukauna, WI. The sedimentation basin was designed to capture agricultural runoff and tile drainage from a 10-hectare crop field. Field management included a corn-soy-alfalfa rotation and fertilizer additions of dairy manure and urea. Sedimentation basins primarily remove particulate P, and future designs would benefit from a sedimentation basin and filter media tank treatment train for total P removal. Furthermore, filter media used for treatment of agricultural runoff without a sedimentation basin would be susceptible to clogging. Agricultural runoff was spiked to a concentration of 0.5 mg P/L using KH 2 PO 4 , representative of elevated dissolved P concentrations measured in agricultural runoff (Stuntebeck et al. 2011 ). A 10-minute hydraulic retention time (0.9 mL/min) was used for the agricultural runoff trials to measure treatment potential. Influent and effluent were collected every 40 hours over a period of 200 hours to evaluate treatment potential of real agricultural runoff. Analysis A discrete analyzer (AQ300; SEAL Analytical, Mequon, Wisconsin) was used to measure ortho-phosphate in flow through samples following U.S. EPA method 118-D Rev 1. The elemental composition of filter media pellet type was determined by XRF using method ME-XRF26 and organic matter was determined using loss on ignition (LOI) at 1000℃ (conducted by ALS Geochemistry; North Vancouver, BC, Canada). LOI likely overestimated the amount of organic matter in each pellet type due to being performed at a temperature higher than 440℃ which likely caused the destruction of inorganic carbonates in addition to organic carbon (Schumacher 2002 ). Act2 in Geochemists Workbench (GWB) (Community Edition 17.0.2) was used to create stability diagrams of HPO 4 2− in the presence of Ca at different activities (1x10 − 3 and 1x10 − 6 ) to determine potential mineral phases present at different pH. Analysis of variance (ANOVA) and Tukey’s HSD (α = 0.05) were used to determine statistical difference of P removal capacities across each factor (i.e. different retention times and pH) and across each filter media for retention time and pH using IBM SPSS Statistics (Version 27). Cost Estimate of Filter Media To determine how practical the deployment of the tested filter media would be, the mass of filter media required, and cost estimate were determined for a theoretical constructed pond wetland system. In practice, the filter media would be installed after a sedimentation basin to remove dissolved P from pretreated runoff with lower suspended sediment. The theoretical constructed pond wetland system is based on preliminary results from a pond wetland system treating 10.1 hectares producing an annual average of 30,000 m 3 (effluent load of 7 kg P). The mass of filter media required was determined using the P removal capacity of the filter media at 20% exhaustion and was adjusted to account for the inefficiency of filter media between synthetic runoff and real agricultural runoff. The cost estimate was determined using the mass of filter media required, estimated cost of pyrolysis, cost of Portland cement, lime, and sand (Table 2 ), and the pellet mixture ratios for each pellet type (full calculations are available in the supplementary information). The DWTR and AMD residual are typically land applied or landfilled; were obtained at no cost and subsequently was not included in the total cost of materials. Table 2 Cost of materials Material Cost Pyrolysis $ 0.08/kg Portland Cement $ 0.36/kg Lime $ 0.72/kg Sand $ 0.41/kg Note – Average estimated cost of pyrolysis is $0.01/kg - $0.14/kg (Shackley et al., 2011 ). Portland cement (SKU# 1891149), lime (SKU# 1891056), and sand (SKU# 1891344) were obtained from Menards (De Pere, WI). Potential for Use of Filter Media in Constructed Pond Wetland Systems To determine the practicality of use of each filter media in an ARTS, the filter media were each given a score and ranked against each other based on an additive scoring system modified from Ballantine and Tanner ( 2010 ) and Nguyen et al. ( 2020 ) on important criteria including P-removal potential, likely cost, energy consumption, use of waste materials, and efficacy in real agricultural runoff. Results and Discussion Chemical Composition Based on chemical analysis of the pelletized media, cement and DWTR pellets were a Ca/Mg/Al-based media (Table 3 ) primarily consisting of silicon (Si), calcium (Ca), magnesium (Mg), and aluminum (Al). The presence of an Al-based coagulant in the DWTR contributed to the higher Al content in the DWTR pellets. The AMD pellets were Ca/Fe-based media (Table 3 ), containing more iron (Fe). Fe-rich hydrated oxides produced from the neutralization of AMD (Sibrell and Tucker 2012 ) resulted in the increased Fe oxide content of the AMD pellets. Reductions in Ca, and Mg in the DWTR and AMD pellets were due to decreased amounts of Portland cement, lime, and sand. Table 3 Elemental composition by XRF analysis of cement, modified DWTR + cement binder pellets, and modified AMD residual + cement binder pellets prior to column experiments. LOI = loss on ignition at 1000°C and represents organic matter plus inorganic carbon content. Cement DWTR AMD Pyrolyzed (CEM-P) Non-Pyrolyzed (CEM) Pyrolyzed (RCB-P) Non-Pyrolyzed (RCB) Raw Pyrolyzed (ACB-P) Non-Pyrolyzed (ACB) SiO 2 38.8 35.3 37.0 33.9 28.0 29.1 27.7 CaO 29.6 28.2 25.1 22.6 7.5 22.3 21.3 MgO 10.4 9.8 9.3 8.3 3.9 7.0 6.7 Al 2 O 3 2.7 2.5 7.2 6.6 17.2 2.3 2.1 Fe 2 O 3 1.4 1.4 1.8 1.6 2.1 21.3 20.4 SO 3 1.0 0.9 1.0 0.9 0.6 0.9 0.8 K 2 O 0.7 0.6 1.0 0.9 1.4 0.5 0.5 Na 2 O 0.4 0.3 0.4 0.4 0.4 0.3 0.2 TiO 2 0.2 0.2 0.2 0.2 0.2 0.1 0.1 P 2 O 5 0.0 0.0 0.1 0.1 0.3 0.2 0.2 MnO 0.1 0.0 0.1 0.0 0.0 0.4 0.4 BaO 0.0 0.0 0.0 0.0 0.0 0.0 0.0 SrO 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Cr 2 O 3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 LOI @ l000°C 14.6 20.4 16.9 24.1 38.5 14.6 19.0 Note – CEM = cement binder, CEM-P = cement binder + pyrolysis, RCB = cement binder + DWTR, RCB-P = cement binder + DWTR + pyrolysis, ACB = cement binder + AMD, ACB-P = cement binder + AMD + pyrolysis. Breakthrough Experiments using Synthetic Runoff Pyrolysis of media greatly impacted removal capacity of P from synthetic agricultural runoff and the pyrolyzed cement binder pellet (CEM-P) had significantly greater P removal than other media evaluated (2268 mg P/kg media at exhaustion; Table 4 ). Pyrolysis increased the P removal capacity of the pellets that contained metal residuals across all factors and improved performance 2-fold for CEM and ACB and 17-fold for RCB at exhaustion (Table 4 ). The performance of the pyrolyzed DWTR pellets were increased due to a reduction in organic matter and an increase in Al oxide (Truong and Kim 2021 , Kuster et al. 2021 ; Table 3 ) which increased P removal through adsorption to Al-(hydr-)oxides or precipitation of Al-phosphates (Qin et al. 2018 ). Previous studies of Ca based materials (waste concrete; Liu et al. 2020 ) and (seashells; Paradelo et al. 2016 ) noted that pyrolysis increased P removal by oxidizing calcium carbonate into calcium oxide. CEM-P had a higher percent P removal over time and took the longest to exhaust compared to the other non-pyrolyzed pellets (Table 4 ). CEM-P had the highest P removal capacity (2268 mg P/kg media) but ACB and ACB-P had the highest P removal efficiency (70% and 72% respectively; Table 4 ). The cumulative P removal efficiency of CEM-P likely appeared lower due to the longer time to exhaustion (Fig. 3 ). ACB and ACB-P were the most efficient before exhaustion compared to the other media but exhausted faster than CEM-P. More ligand exchange occurred with ACB and ACB-P due to the high Fe content (20% and 21% respectively) which caused a faster removal of P but also consumed reactive sites faster than CEM-P (Penn et al., 2017). Table 4 Phosphorus removal capacity of each media at pH 6–1 min retention, cumulative P removal efficiency, and time each media reached 20% exhaustion. Note – standard deviation in parenthesis. Media with the same letter are not statistically different at α = 0.05. Media ID P Removal Capacity (mg P/kg media) Cumulative P Removal Efficiency (%) Time (hour) Cement binder (sand, lime, cement) CEM 1397 (43) c 67 (2) bc 240 Cement binder + pyrolysis CEM-P 2268 (63) e 54 (1) b 432 Cement binder + DWTR RCB 71 (3) a 34 (3) a 12 Cement binder + DWTR + pyrolysis RCB-P 1178 (55) b 67 (3) bc 144 Cement binder + AMD residual ACB 1007 (155) b 71 (14) bc 136 Cement binder + AMD residual + pyrolysis ACB-P 1685 (4) d 72 (1) c 244 Additions of AMD and DWTR significantly decreased removal of the non-pyrolyzed cement pellets with the DWTR and cement pellet having the lowest P removed. Decreased performance of the pellets with metal residuals could be caused by decreasing the Ca content (i.e. Portland cement and lime) by adding DWTR and AMD in the pellet mixture. Decreasing the Ca content would lower P removal by decreasing the precipitation of hydroxyapatite which is likely the main removal mechanism (Littler et al., 2013 ). Cement will also immobilize metals (Jo et al., 2023 ), as cement is also used for solidification and stabilization to slow the release of harmful chemicals, which could have also lowered treatment potential of media with metal residuals (i.e. DWTR and AMD). Portland cement and lime in the cement binder mixture will precipitate metals forming insoluble hydroxides with impervious coatings, inhibiting P reactions with the added metals (Cartledge et al., 1990 ). Future studies pelletizing metal residuals should evaluate other binders (e.g. clays, chitosan) to decrease metal immobilization and increase reactivity. The P removal capacity of RCB-P and ACB-P were within the range of other reactive media in flow through column studies including electric arc furnace slag, coal ash, shellsand, and Filtralite PTM (Table 5 ). However, removal capacities for P of both DWTR and AMD residual pellets were lower than measured removal of raw DWTR and AMD in previous literature (Table 5 ), likely as a result of differences in experimental design and physiochemical properties of residuals. The differences in P removal could be influenced by different experimental conditions including initial P concentration, batch vs column experiments, retention time, exhaustion definition, and differences in the physical and chemical composition of DWTR and AMD residual (e.g. Al/Fe content, particle size, surface area). Table 5 Comparison of P removal capacities (mg P/kg media) between cement binder + DWTR + pyrolysis (RCB-P), cement binder + AMD residual + pyrolysis (ACB-P), and other reactive media in flow through column studies. Filter Media P Removal Capacity (mg P/kg media) Cement binder + DWTR + pyrolysis 1,178 Cement binder + AMD residual + pyrolysis 1,685 Electric arc furnace slag 2,200 (Drizo et al., 2006 ) Coal ash 300 (Drizo et al., 1999 ) Shellsand 497-3,500 (Àdàm et al., 2007 ; Roseth, 2000 ) Filtralite PTM 497 (Àdàm et al., 2006 ) Raw DWTR 2,000–43,000 (Muisa et al., 2020 ) Raw AMD residual 9,890–31,970 (Wei et al., 2008 ) Impact of pH and Retention Time on P Removal The P removal efficiency of the filter media was not significantly impacted by changes in influent water pH except for CEM-P (Table 6 ) due to a lower standard deviation measured for the pH 8 trial. The main P removal mechanisms of the media are likely through hydroxyapatite precipitation reactions of Ca/Mg-phosphate minerals (Supplementary Information Figure S3; Stoner et al., 2012 ). The media has a high pH and buffer capacity that maintained a pH that favors the precipitation of hydroxyapatite regardless of influent pH (Penn et al. 2011 ). Filter media can be deployed to treat agricultural runoff with a pH of 6 and above without impacting P removal. Table 6 Cumulative P removal efficiency of each media at varying pH (i.e. 6, 8, and 10) with a 1-min retention. Note – standard deviation in parenthesis. Different letters indicate statistical significance between media for individual conditions (i.e. pH 6, 8, and 10) at α = 0.05. Media ID pH 6 pH 8 pH 10 Cement binder (sand, lime, cement) CEM 82 (5) b 80 (15) b 81 (7) bc Cement binder + pyrolysis CEM-P 85 (2) b 93 (0.5) b 85 (4) bc Cement binder + DWTR RCB 29 (3) a 27 (4) a 22 (1) a Cement binder + DWTR + pyrolysis RCB-P 73 (8) b 74 (2) b 77 (6) b Cement binder + AMD residual ACB 75 (11) b 91 (6) b 86 (5) bc Cement binder + AMD residual + pyrolysis ACB-P 88 (3) b 92 (1) b 91 (1) c Retention time greatly impacted P removal efficiency of the media from synthetic agricultural runoff as a result of removal mechanisms. Increasing the retention time from 1- to 5-min significantly increased the P removal efficiency between 8-134%. The filter media benefited from an increased retention time due to hydroxyapatite precipitation, the main hypothesized P-removal mechanism, which removed P slower and is impacted by changes in retention time (Stoner et al., 2012 ). RCB was the only media that had a significant difference between a 5- and 10-min retention time and was the most impacted by increases in retention time (134% increase from 1 to 5-min retention and 26% increase from 5 to 10-min retention; Table 7 ) due to an elevated organic matter content (24%; Table 3 ) which slowed the diffusion of P into micropores which increased treatment potential with increased contact time (Makris et al., 2005 ). ACB-P was least impacted by changes in retention time (8% increase in P removal efficiency from 1 to 5-min retention; Table 7 ) due to a higher content of Fe (20%, Table 3 ), Fe-based materials remove P mostly through ligand exchange reactions which are less impacted by retention time because they occur faster than precipitation reactions (Penn et al., 2017). Pyrolyzed media were also less impacted by increases in retention time than the non-pyrolyzed media which also supports the impact of OM on P removal efficiency. Each media type, especially non-pyrolyzed media, would perform best in treatment systems with longer retention times (between 1–5 minute) than shorter contact high flow systems. Table 7 Average cumulative P removal efficiency (%) of each media at multiple retention times (i.e. 1, 5, and 10 min) treating synthetic runoff at pH 6. Media ID 1-min retention 5-min retention 10-min retention Cement binder (sand, lime, cement) CEM 82 (5) b 95 (3) b 95 (2) b Cement binder + pyrolysis CEM-P 85 (2) b 96 (2) b 98 (2) bc Cement binder + DWTR* RCB 29 (3) a 68 (3) a 86 (1) a Cement binder + DWTR + pyrolysis RCB-P 73 (8) b 96 (1) b 99.7 (0.1) bc Cement binder + AMD residual ACB 75 (11) b 97 (1) b 97 (0.7) bc Cement binder + AMD residual + pyrolysis ACB-P 88 (3) b 95 (3) b 98 (0.5) bc Note – standard deviation in parenthesis. Media with an * are statistically different between 1-, 5-, and 10-min retention at α = 0.05, media without an * are statistically different between 1- and 5-min retention. Different letters indicate statistical significance between media for individual conditions (i.e. 1, 5, and 10-min retention) at α = 0.05. Effectiveness of P Removal from Field-Sourced Agricultural Runoff Field-sourced agricultural runoff decreased the P removal efficiency of each media between 13–55% compared to synthetic runoff with a 10-min retention. The decreased performance of the media was due to the presence of bicarbonate in the agricultural runoff which can form calcite minerals and reduce P removal by clogging the pore structure (Penn et al., 2020 ). Even with a decreased efficacy of P removal, these media still have significant potential to remove P from agricultural runoff in edge of field treatment systems. RCB-P had similar P removal efficiencies as CEM and CEM-P (77%, 78%, and 85% respectively; Table 8 ). CEM-P was the least impacted by field-sourced agricultural runoff (13% decrease) and RCB was most impacted (55% decrease) which is correlated with how well the media performed overall (i.e. CEM-P had higher P removal than RCB at each factor). The filter media was not run to exhaustion with real agricultural runoff and should be considered for future studies. Before being considered for field deployment, P removal capacities of filter media should be investigated at faster flow rates (i.e. between 1- to 5-min retention) to determine optimal retention times. Table 8 Average cumulative P removal efficiency (%) of each media treating agricultral runoff with a 10-min retention. Note – standard deviation in parenthesis and media with the same letter are not statistically different at α = 0.05. Media ID 10-min retention Cement binder (sand, lime, cement) CEM 78 (8) c Cement binder + pyrolysis CEM-P 85 (6) c Cement binder + DWTR RCB 39 (1) a Cement binder + DWTR + pyrolysis RCB-P 77 (4) c Cement binder + AMD residual ACB 54 (7) ab Cement binder + AMD residual + pyrolysis ACB-P 68 (11) bc Cost Estimate of Filter Media CEM-P was the least costly media, costing $ 1,936 to treat 10.1 ha with a load of 7 kg P and would require the least amount of material (3,488 kg; Table 9 ). The least costly media that included a waste product was ACB-P, which would cost slightly more than CEM-P ( $ 2,159) but would require more mass to treat the same amount of runoff (5,442 kg; Table 9 ). CEM-P had a higher P removal capacity and a lower percent inefficiency at agricultural runoff treatment than ACB-P which resulted in less mass being required for treatment but was only slightly less costly than ACB-P because ACB-P required less Portland cement, lime, and sand due to containing a waste product (i.e. AMD residual). Pyrolyzed media (i.e. CEM-P, RCB-P, and ACB-P) are less costly than the non-pyrolyzed media (i.e. CEM, RCB, and ACB) due to a higher P removal capacity (less mass required to remove the same amount of P). Other best management practices (BMPs) are less costly to treat the same amount of P (7 kg) including buffer strips ( $ 562- $ 700; Balana et al. 2012 ), minimum tillage ( $ 316; Haygarth et al. 2009 ), injection ( $ 1,349; Haygarth et al. 2009 ), incorporation ( $ 123; Haygarth et al. 2009 ), and cover cropping ( $ 538; Haygarth et al. 2009 ). The estimated costs of these BMPs could underestimate the true cost due to limitations of the models used, not including all associated costs, inflation, and could vary based on soil type and landscape of the treatment area. Filter media may be more expensive than other BMPs but has measurable treatment by having the ability to test runoff before and after flowing through the filter media (beneficial to nutrient trading), promotes a circular economy if it contains a waste product, and reduces the added expense of agricultural machinery and time to implement these practices. Table 9 Mass and cost of filter media required to treat the example ARTS. Media ID Mass Cost Cement binder CEM 5,913 kg or 585 kg/ha $ 2,809 or $ 278/ha Cement binder + pyrolysis CEM-P 3,488 kg or 345 kg/ha $ 1,936 or $ 192/ha Cement binder + DWTR RCB 152,817 kg or 15,130 kg/ha $ 48,392 or $ 4,791/ha Cement binder + DWTR + pyrolysis RCB-P 7,291 kg or 722 kg/ha $ 2,892 or $ 286/ha Cement binder + AMD residual ACB 10,010 kg or 991 kg/ha $ 3,170 or $ 314/ha Cement binder + AMD residual + pyrolysis ACB-P 5,442 kg or 539 kg/ha $ 2,159 or $ 214/ha Potential for Use of Filter Media in Constructed Pond Wetland Systems Based on an additive scoring system modified from Ballantine and Tanner ( 2010 ) and Nguyen et al. ( 2020 ), CEM, CEM-P, RCB-P, and ACB were the most practical media (Table 10 ) to be used in a constructed pond wetland system but they each have different benefits and drawbacks. CEM was low cost ( $ 2,809; Table 9 ), had a high potential to remove P from agricultural runoff, and a medium P removal capacity but did not use a waste product and had a medium energy consumption due to the energy required to make the Portland cement and lime. CEM-P was also low cost ( $ 1,936), had a high P removal capacity, and high potential to remove P from agricultural runoff but did not use a waste product and had high energy consumption due to the pellet components and the energy required for pyrolysis. RCB-P was low cost ( $ 2,892), contained a waste product (33% DWTR), had high potential to remove P from agricultural runoff, and had a medium P removal capacity but had a high energy consumption due to the energy required for pyrolysis. ACB was low cost ( $ 3,170), used a waste material (33% AMD residual), had a low energy consumption due to needing a decreased amount of Portland cement and lime and was not pyrolyzed, had a medium P removal capacity but had a low potential to remove P from agricultural runoff. RCB was the least practical media tested due to having a high cost to deploy ( $ 48,392), and low P removal (34% P removal efficiency of synthetic runoff at 20% exhaustion and 39% P removal efficiency of agricultural runoff) even though this media had a low energy consumption and used a waste product (33% DWTR). The filter media have the potential to be used as a permeable concrete to remove P from agricultural runoff. Previous studies of permeable concrete have been shown to remove pollutants, including P, from stormwater runoff (Wu et al. 2021 ). The P removal of ordinary permeable concrete can be improved by replacing gravel or sand, which are used as an aggregate, with other materials that have a higher P removal (Wu et al. 2021 ). Permeable concrete containing fly ash (Jo et al. 2015 ), iron oxide (Vázquez-Rivera et al. 2015 ), and ordinary Portland cement (Agyei et al. 2002 ) have increased the P removal of ordinary pervious concrete. Quan et al ( 2024 ) modified permeable concrete, which normally consists of gravel and cement-based materials, by replacing gravel with industrial solid wastes (i.e. fly ash and granulated blast furnace slag) and achieved a phosphorus removal capacity of 88.93 mg/g. Future studies should be conducted to evaluate the use of heat treated DWTR and AMD pellets in permeable cement. Table 10 Filter media score for use in an ARTS. Media ID P-Removal Potential Likely Cost Energy Consumption Efficacy in Real Agricultural Runoff Use of Waste Materials Total Cement binder CEM Medium Low Medium High Low 11 Cement binder + pyrolysis CEM-P High Low High High Low 11 Cement binder + DWTR RCB Low High Low Low Medium 8 Cement binder + DWTR + pyrolysis RCB-P Medium Low High High Medium 11 Cement binder + AMD residual ACB Medium Low Low Low Medium 11 Cement binder + AMD residual + pyrolysis ACB-P Medium Low High Low Medium 9 Note – Score determined by addition. P-removal potential: low = 1, medium = 2, high = 3; Likely cost: low = 3, medium = 2, high = 1; Energy consumption: low = 3, medium = 2, high = 1; Efficacy in real agricultural runoff: low = 1, medium = 2, high = 3; Use of waste material: low = 1, medium = 2, high = 3. Conclusion Modified DWTR and AMD residual have the potential to be used as a filter media to remove P in a constructed pond wetland system. Pyrolysis of the media and increased retention time (5-min) had positive impacts on P removal while adding DWTR and AMD to the cement binder decreased P removal. Agricultural runoff decreased the performance of the filter media compared to synthetic runoff. CEM-P is the least costly material and requires the least amount of material for field scale deployment at a constructed pond wetland system. Future studies should evaluate the use of other binding materials and determine the optimal retention time between 1- to 5-min retention. Declarations Acknowledgements The authors would like to acknowledge Dr. Joseph Sanford (University of Wisconsin – Platteville), Paul Reneau (USGS), Jeremy Freund (Outagamie County), Dr. Kevin Fermanich (University of Wisconsin – Green Bay), Dr. Chad Penn (USDA), Holly lab students (University of Wisconsin – Green Bay), Green Bay Water Utility, and Heart of the Valley Metropolitan Sewerage District. Funding This work is supported by Capacity Building Grants for Non-Land-Grant Colleges of Agriculture Program [USDA-NIFA-NLGCA-009505] from the USDA National Institute of Food and Agriculture. Authors Contributions Beth Kondro: experimentation; analysis; writing; original draft preparation; Michael Holly: methodology; analysis; writing; review and editing Ethical Approval Not applicable. Consent to Participate Not applicable. Consent to Publish Not applicable Competing Interests The authors declare no competing interests. Data Availability Statement The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request. References Àdàm K, Søvik AK, Krogstad T (2006) Sorption of phosphorous to Filtralite-P ®—the effect of different scales. 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Wu F, Yu Q, Gauvin F, Brouwers HJH, Liu C (2021) Phosphorus removal from aqueous solutions by adsorptive concrete aggregates. J Clean Prod 278:. https://doi.org/10.1016/j.jclepro.2020.123933 Zou J, Xu G, Pan K, Zhou W, Dai Y, Wang X, Zhang D, Hu Y, Ma M (2012) Nitrogen removal and biofilm structure affected by COD/NH4+–N in a biofilter with porous sludge-ceramsite. Sep Purif Technol 94:9-15. https://doi.org/10.1016/j.seppur.2012.03.019. Supplementary Files ResubmitLetter.docx SupplementalInformation.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. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6347283","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":452062096,"identity":"9fafd5b2-1ef1-4e6c-8435-e2c92bb8adf5","order_by":0,"name":"Beth Kondro","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAt0lEQVRIiWNgGAWjYBACCQg+IAek2YCYmXgtxqRrSWwgWotke+/B2xUVd9I33Ei/9oChwhqkFz+Q5jmXbHnmzLPcDTdyyg0YzqQT1iInkWMm2dh2OHfD7Zw0Cca2w8RrSTcAa/lHhBZpqJYEg9vpxyQYG4jQItlzxtiy4cwzw5n337AbJBxLNyaoReJ4j+HNhoo78nxnjj978KHGWpagFiTAY8CQQIJyEGB/QKKGUTAKRsEoGCkAAB/uQz6uiVFIAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0009-0006-9593-0295","institution":"University of Wisconsin-Green Bay","correspondingAuthor":true,"prefix":"","firstName":"Beth","middleName":"","lastName":"Kondro","suffix":""},{"id":452062097,"identity":"c9d6ad9c-f435-4260-9e78-500b5e2e32a0","order_by":1,"name":"Michael A. Holly","email":"","orcid":"","institution":"University of Wisconsin-Green Bay","correspondingAuthor":false,"prefix":"","firstName":"Michael","middleName":"A.","lastName":"Holly","suffix":""}],"badges":[],"createdAt":"2025-03-31 18:38:59","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6347283/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6347283/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":82236496,"identity":"891c9cbb-1829-405a-9daf-1e18480497bd","added_by":"auto","created_at":"2025-05-08 07:09:31","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":144992,"visible":true,"origin":"","legend":"\u003cp\u003eSetup of flow-through columns\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6347283/v1/28bd667f1db17555ca8f82e0.jpeg"},{"id":82236490,"identity":"3094edb4-84f8-4c6c-ba83-6cb95797a94a","added_by":"auto","created_at":"2025-05-08 07:09:31","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":51400,"visible":true,"origin":"","legend":"\u003cp\u003eFlow chart of experimental procedure\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6347283/v1/22a1502084303ddfff1fa57c.jpg"},{"id":82236491,"identity":"050009bf-18cf-4c56-970e-26f08c4f5582","added_by":"auto","created_at":"2025-05-08 07:09:31","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":35876,"visible":true,"origin":"","legend":"\u003cp\u003eCumulative P removal (mg P/kg media) and cumulative P added (mg P/kg media) of each media type after filtering synthetic agricultural runoff spiked to 0.5 mg P/L until exhaustion (≤20% P removal). Note – ACB = cement binder + AMD residual, ACB-P = cement binder + AMD residual + pyrolysis, CEM = cement binder, CEM-P = cement binder + pyrolysis, RCB = cement binder + DWTR, RCB-P = cement binder + DWTR + pyrolysis.\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6347283/v1/c0050a93a21c1c1b5b18bcc1.jpg"},{"id":93712831,"identity":"e85038cb-3762-49a6-a107-bf1a2a44b09a","added_by":"auto","created_at":"2025-10-16 18:39:51","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1087667,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6347283/v1/4bbf09d1-069c-46d9-ae92-4a68e4435bc0.pdf"},{"id":82236497,"identity":"4b274bee-8341-4dbd-8d98-a8a1917c89eb","added_by":"auto","created_at":"2025-05-08 07:09:31","extension":"docx","order_by":5,"title":"","display":"","copyAsset":false,"role":"supplement","size":1103884,"visible":true,"origin":"","legend":"","description":"","filename":"ResubmitLetter.docx","url":"https://assets-eu.researchsquare.com/files/rs-6347283/v1/a1917f7506a6f1af582e71ce.docx"},{"id":82236505,"identity":"dc30b38e-ca9a-4fe2-8c37-a77340da7d9a","added_by":"auto","created_at":"2025-05-08 07:09:32","extension":"docx","order_by":6,"title":"","display":"","copyAsset":false,"role":"supplement","size":1575733,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementalInformation.docx","url":"https://assets-eu.researchsquare.com/files/rs-6347283/v1/b7171bec641b3b945a4df3b7.docx"}],"financialInterests":"","formattedTitle":"Reactive cement pellet media including drinking water treatment and mine drainage residuals for phosphorus removal in agricultural runoff","fulltext":[{"header":"Introduction","content":"\u003cp\u003eExtensive nutrient loads result in harmful algal blooms in waterbodies throughout the Mississippi River basin and Great Lakes region (Kalcic et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Algal blooms decay and decrease dissolved oxygen, impairing Great Lakes freshwater ecosystems (Robertson and Saad \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). Agricultural operations can have a negative impact on water quality by releasing high nitrogen and phosphorus (P) loads to surface water (Kalcic et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Subsurface tile drainage is an additional source of P loss (consisting of 21\u0026ndash;68% dissolved P; Madison et al, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2014\u003c/span\u003e) from agricultural fields, routing infiltrated precipitation and nutrients to surface waters (Tanner et al. \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). Constructed wetlands and sedimentation basins can be constructed to intercept sediment flow and reduce particulate-P (Sharpley et al., \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2006\u003c/span\u003e). Reactive filter media incorporated within constructed wetlands may result in enhanced P removal through adsorption of dissolved P.\u003c/p\u003e \u003cp\u003ePreviously investigated reactive filter material for the removal of dissolved P can be categorized as natural, industrial by-products, and man-made (engineered) (Vohla et al. \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). The ideal filter media would be a local waste material that is low cost to benefit a circular economy. Efficient media for P removal has significant mass composition of calcium (Ca), iron (Fe), and aluminum (Al), and most of the media that has been studied contains a high percent of Ca and/or CaO (Vohla et al. \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). Drinking water treatment residuals (DWTR), the waste by-products from the drinking water treatment process, include common coagulants Fe or Al and can be reused as an adsorbent for P (Nguyen et al. \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). The properties of DWTR depend on the source of the water being treated and the methods used to treat the water, including the type of coagulant (Ahmad et al, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). The aluminum content of DWTR from plants using aluminum coagulants is on average approximately 16% of the chemical composition by weight (Muisa et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Other main components of DWTR include Ca, SiO\u003csub\u003e2\u003c/sub\u003e\u003csup\u003e2\u0026minus;\u003c/sup\u003e, Fe, Cl\u003csup\u003e\u0026minus;\u003c/sup\u003e, SO\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e2\u0026minus;\u003c/sup\u003e, and humic acids (Nguyen et al. \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Metal oxides, capable of reacting with phosphorus, measured in DWTR include CaO, MgO, Na\u003csub\u003e2\u003c/sub\u003eO, K\u003csub\u003e2\u003c/sub\u003eO, and P\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e and some trace metals (Nguyen et al. \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Previously measured P removal capacity of aluminum based DWTR varies depending on experimental design (batch or column) and conditions (pH, particle size, initial P concentration), resulting in a large range of measured P removal capacities (2 to 43 mg P/g DWTR: Muisa et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). DWTR adsorption of P in DWTR amended constructed wetlands accounts for 59\u0026ndash;75% of the dissolved P removed (Kumar et al, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2011\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eAcid mine drainage (AMD) has negative environmental impacts by containing high concentrations of dissolved metals and having a low pH (Johnson and Hallberg, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2005\u003c/span\u003e). AMD residual is the product remaining after the AMD is treated to neutralize the pH and to precipitate heavy metals and is then disposed of (Roger et al, 2006). AMD residual are rich in Fe and Al hydrated oxides (Sibrell et al, 2012). AMD residual has a high potential to be used as a sorbent for P removal from agricultural runoff (Penn et al, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2007\u003c/span\u003e) which would provide a beneficial reuse of AMD before disposal which would support a circular economy.\u003c/p\u003e \u003cp\u003eMetal residuals, such as AMD and DWTR, lack mechanical strength, have heterogenous particle size, and low hydraulic conductivities increasing the potential clogging in filtration systems (Li et al. \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Filtration systems including constructed wetlands commonly use a media size of 5\u0026ndash;20 mm (Vymazal and Kropfelova, 2008), uncommon for raw DWTR and AMD. Raw DWTR and AMD must be converted into a granular form with a high mechanical strength for use as a filter media in a wetland. Common technologies that have been developed to convert raw DWTR into a granular form include pelletizing and sintering (Zou et al, \u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e2012\u003c/span\u003e), wood loading (Soleimanifar et al, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2016\u003c/span\u003e), and gel entrapment (Jung et al, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). We evaluated the use of pelletized DWTR and AMD residual to remove dissolved P from agricultural runoff through flow through bench-top laboratory studies to determine P-removal potential and removal efficiency at different pH concentrations, retention times, and effectiveness for real agricultural runoff. Bench-top flow-through trials were used to control the environment, increase replicates, study several factors, scalability, efficiency, and reduce costs.\u003c/p\u003e \u003cp\u003eThe novelty of this work is the development of a DWTR and AMD cement binder pellet, produced from a pellet mill, for the treatment of agricultural runoff. In addition, the evaluation of filter media used real agricultural runoff and representative retention times to determine flowrate for scalability. To the best of the authors' knowledge this is the first-time cement, DWTR, and AMD pellets, with and without heat treatment, were produced using a scalable method (i.e. pellet mill) for the removal of P from agricultural runoff.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003eMaterials\u003c/p\u003e \u003cp\u003eDWTR was obtained from the Green Bay Water Utility treating raw water pumped from Lake Michigan near the City of Kewaunee through ozonation, coagulation with sodium hypochlorite and polyaluminum chloride (PACl), flocculation, sedimentation, and filtration. The use of a PACl coagulant resulted in an aluminum-based drinking water treatment residual (DWTR) which was passively dewatered in a settling pond (Shown in Supplementary Information Figure \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e). The DWTR were collected in August 2022 and April 2023 in buckets, partially dried, and sieved to \u0026lt;\u0026thinsp;4mm. The sieved DWTR were then dried at 105℃ for 24 hours before pelletizing. AMD residual was sourced from the Blue Valley Mine Drainage Treatment and Fish Culture Station in Camp Brandy, PA as described in Sibrell P.L., and Tucker T.W. (2012).\u003c/p\u003e \u003cp\u003ePhysical and Chemical Modification\u003c/p\u003e \u003cp\u003eDWTR and AMD required a binder to increase mechanical strength, minimize dissolution in water, create a uniform particle size, and reduce clogging. Cement and AlCl\u003csub\u003e3\u003c/sub\u003e were both investigated as potential binders. While the AlCl\u003csub\u003e3\u003c/sub\u003e binder increased mechanical strength when dry, it lost strength upon exposure to water. Consequently, cement was used as a binder for the pellets in this study. Cement was a more effective binder than AlCl\u003csub\u003e3\u003c/sub\u003e as it forms stable solid hydrates when reacting with water (Naqi and Jang, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Optimal ratios of binder (i.e. sand, lime, and cement; Shown in Supplementary Information Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e) for mechanical strength were evaluated by hand rolling test balls of mixtures into spheres (2 and 4 mm) and air drying for 24 hours. Insolubility and mechanical strength were evaluated by soaking the pellets in water for 24 hours and compressing pellets by hand (Shown in Supplementary Information Table \u003cspan refid=\"MOESM2\" class=\"InternalRef\"\u003eS2\u003c/span\u003e). Visible inspection and tactile evaluations were performed to determine binder type and optimal ratio for flow through analysis (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The optimal binder ratio that was used to create the pellets is a ratio of 1 part lime, 1 part Portland cement, and 2 parts sand.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePellet mixture ratio for each pellet type.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePellet Type\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eID\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePellet Mixture Ratio\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder (sand, lime, cement)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCEM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 Lime : 1 PC : 2 Sand\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder w/ pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCEM-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 Lime : 1 PC : 2 Sand\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;DWTR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRCB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 Lime : 1 PC : 2 Sand : 2 DWTR\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;DWTR w/ pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRCB-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 Lime : 1 PC : 2 Sand : 2 DWTR\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;AMD residual\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eACB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 Lime : 1 PC : 2 Sand : 2 AMD residual\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;AMD residual w/ pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eACB-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 Lime : 1 PC : 2 Sand : 2 AMD residual\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003ePellet mixtures were made into pellets by incorporating approximately 20% DI water by mass with a drill-powered paint mixer and pelletizing using vertical pellet mill (220 V Three Phase; PelletMasters, Chippewa Falls, Wisconsin) with a 3 mm diameter die plate. A portion of each pellet type were heat treated through pyrolysis (N\u003csub\u003e2\u003c/sub\u003e gas purged chamber held at 600ᵒC for 15 min) to improve P removal potential by increasing the pore size, removing organic matter, increasing metal concentrations, and oxidizing calcium carbonate. Control test pellets included a cement binder (CEM), pyrolyzed cement binder (CEM-P), cement binder\u0026thinsp;+\u0026thinsp;DWTR (RCB), and cement binder\u0026thinsp;+\u0026thinsp;AMD (ACB) to determine the impact of the cement binder, DWTR, AMD, and pyrolysis on P removal.\u003c/p\u003e \u003cp\u003eFlow Through Columns\u003c/p\u003e \u003cp\u003eConventionally, batch and column experiments are both used to evaluate the removal of contaminants (Wang et al., \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). Batch experiments neglect actual solid to liquid ratios and contact times from field observations, overestimating filter media removal (Wang et al., \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). Column experiments, used in the current study, offer a more realistic simulation of the real environment because the contaminant travels through the pore spaces of the solid packed in the column (Wang et al., \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e2009\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eFlow-through experiments were evaluated in triplicate and consisted of 1.8 cm diameter PVC pipes that were 60 cm long (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Each column was loosely packed with 7.6 cm of filter media (17\u0026ndash;25 g) and about 2 cm of glass beads on each side separated by glass wool. To determine P removal potential, filter performance over time, and exhaustion, columns received synthetic agricultural runoff at a 1-minute retention time until exhaustion (20% P removal; Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). A 1-minute retention time was selected as this would enable a small footprint and is representative of a short retention time (\u0026lt;\u0026thinsp;10 minutes) in comparison with previous field trails (Penn et al. 2017). Synthetic agricultural runoff was prepared by dissolving KH\u003csub\u003e2\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e (\u0026gt;\u0026thinsp;99% purity; Santa Cruz Biotechnology; Dallas, TX) in DI water to obtain a P concentration of 0.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05 mg P/L, with a pH level of 6\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6. Influent and effluent samples were collected at 4-hour intervals for the sorption capacity trials. Factors influential to phosphorus removal were also evaluated through flow through columns including retention time (i.e., 1-, 5-, and 10-min), pH (i.e. 6, 8 and 10) and real agricultural runoff were tested for each media type (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Selected retention times evaluated performance variability across a range of conditions including high and low flow rate. Real agricultural runoff trials elucidated dissolved P treatment interference from suspended solids, organic matter, and other dissolved ions in runoff.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eTrial flow rates to meet retention times (i.e., 1, 5, and 10 minutes) favorable of field deployment were obtained by adjusting the flow rate to 9, 1.8, and 0.9 mL/min respectively using a peristaltic pump. The flow rate was determined using Eq.\u0026nbsp;\u003cspan refid=\"Equ1\" class=\"InternalRef\"\u003e1\u003c/span\u003e:\u003cdiv id=\"Equ1\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ1\" name=\"EquationSource\"\u003e\n$$\\:Q\\:=\\frac{V\\:\\cdot\\:\\:{n}_{e}}{\\tau\\:}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e1\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003ewhere Q is the flow rate (mL/min), V is the bulk volume of media in column (mL), n\u003csub\u003ee\u003c/sub\u003e is the effective porosity (unitless, 0.5), and τ is the hydraulic retention time (min).\u003c/p\u003e \u003cp\u003eCollection times varied with retention time to compare trials across a uniform applied mass of P. The influent and effluent were collected every 20 hours until hour 100 for the 5-minute retention columns and every 40 hours until hour 200 for the 10-minute retention columns. The pH of the synthetic agricultural runoff was adjusted to 8 and 10 using 0.1M NaOH (\u0026gt;\u0026thinsp;97% purity; Acros Orgaincs; Geel, Belgium) to assess its impact on P removal, with testing conducted at a flow rate that produced a 1-minute hydraulic retention time. The influent and effluent from the pH trials were collected every 4 hours until hour 20 (10.8 L). Percent P removal was calculated from measured P in influent and effluent concentrations through Eq.\u0026nbsp;\u003cspan refid=\"Equ2\" class=\"InternalRef\"\u003e2\u003c/span\u003e:\u003cdiv id=\"Equ2\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ2\" name=\"EquationSource\"\u003e\n$$\\:R=\\frac{\\left({C}_{o}-{C}_{e}\\right)}{{C}_{o}}\\cdot\\:100\\%$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e2\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003ewhere R is the percent P removal, C\u003csub\u003eo\u003c/sub\u003e is the average influent concentration (mg P/L), C\u003csub\u003ee\u003c/sub\u003e is the average effluent concentration (mg P/L). The performance of the media was evaluated using the average P removal capacity (mg P/kg media) which was calculated using the following Eq.\u0026nbsp;\u003cspan refid=\"Equ3\" class=\"InternalRef\"\u003e3\u003c/span\u003e:\u003cdiv id=\"Equ3\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ3\" name=\"EquationSource\"\u003e\n$$\\:{q}_{t}={\\Sigma\\:}\\frac{\\left({C}_{o}-{C}_{e}\\right)\\cdot\\:V}{m}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e3\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003ewhere q\u003csub\u003et\u003c/sub\u003e is the P removal (mg P/kg media) at 20% exhaustion or 10.8L, C\u003csub\u003e0\u003c/sub\u003e is the discrete influent concentration (mg P/L), C\u003csub\u003ee\u003c/sub\u003e is the effluent concentration (mg P/L), V is the volume (L) of water treated per each time point, and m is the mass (kg) of media.\u003c/p\u003e \u003cp\u003eThe performance of each filter media was compared using cumulative P removal efficiencies (Penn et al. 2017). Cumulative P removal efficiency was determined by plotting cumulative P removed (equations 4 and 5) as a function of cumulative P added (equations 4 and 5) similarly to Penn et al. (2017). The y-intercept was set to zero and the slope is equal to cumulative P removal efficiency (Penn et al. 2017).\u003c/p\u003e \u003cp\u003eAgricultural Runoff\u003c/p\u003e \u003cp\u003eTo evaluate efficacy of P removal from real agricultural runoff, runoff was sampled from a sedimentation basin receiving agricultural runoff in Kaukauna, WI. The sedimentation basin was designed to capture agricultural runoff and tile drainage from a 10-hectare crop field. Field management included a corn-soy-alfalfa rotation and fertilizer additions of dairy manure and urea. Sedimentation basins primarily remove particulate P, and future designs would benefit from a sedimentation basin and filter media tank treatment train for total P removal. Furthermore, filter media used for treatment of agricultural runoff without a sedimentation basin would be susceptible to clogging. Agricultural runoff was spiked to a concentration of 0.5 mg P/L using KH\u003csub\u003e2\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e, representative of elevated dissolved P concentrations measured in agricultural runoff (Stuntebeck et al. \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). A 10-minute hydraulic retention time (0.9 mL/min) was used for the agricultural runoff trials to measure treatment potential. Influent and effluent were collected every 40 hours over a period of 200 hours to evaluate treatment potential of real agricultural runoff.\u003c/p\u003e \u003cp\u003eAnalysis\u003c/p\u003e \u003cp\u003eA discrete analyzer (AQ300; SEAL Analytical, Mequon, Wisconsin) was used to measure ortho-phosphate in flow through samples following U.S. EPA method 118-D Rev 1. The elemental composition of filter media pellet type was determined by XRF using method ME-XRF26 and organic matter was determined using loss on ignition (LOI) at 1000℃ (conducted by ALS Geochemistry; North Vancouver, BC, Canada). LOI likely overestimated the amount of organic matter in each pellet type due to being performed at a temperature higher than 440℃ which likely caused the destruction of inorganic carbonates in addition to organic carbon (Schumacher \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2002\u003c/span\u003e). Act2 in Geochemists Workbench (GWB) (Community Edition 17.0.2) was used to create stability diagrams of HPO\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e2\u0026minus;\u003c/sup\u003e in the presence of Ca at different activities (1x10\u003csup\u003e\u0026minus;\u0026thinsp;3\u003c/sup\u003e and 1x10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e) to determine potential mineral phases present at different pH. Analysis of variance (ANOVA) and Tukey\u0026rsquo;s HSD (α\u0026thinsp;=\u0026thinsp;0.05) were used to determine statistical difference of P removal capacities across each factor (i.e. different retention times and pH) and across each filter media for retention time and pH using IBM SPSS Statistics (Version 27).\u003c/p\u003e \u003cp\u003eCost Estimate of Filter Media\u003c/p\u003e \u003cp\u003eTo determine how practical the deployment of the tested filter media would be, the mass of filter media required, and cost estimate were determined for a theoretical constructed pond wetland system. In practice, the filter media would be installed after a sedimentation basin to remove dissolved P from pretreated runoff with lower suspended sediment. The theoretical constructed pond wetland system is based on preliminary results from a pond wetland system treating 10.1 hectares producing an annual average of 30,000 m\u003csup\u003e3\u003c/sup\u003e (effluent load of 7 kg P). The mass of filter media required was determined using the P removal capacity of the filter media at 20% exhaustion and was adjusted to account for the inefficiency of filter media between synthetic runoff and real agricultural runoff. The cost estimate was determined using the mass of filter media required, estimated cost of pyrolysis, cost of Portland cement, lime, and sand (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e), and the pellet mixture ratios for each pellet type (full calculations are available in the supplementary information). The DWTR and AMD residual are typically land applied or landfilled; were obtained at no cost and subsequently was not included in the total cost of materials.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCost of materials\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMaterial\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCost\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cspan\u003e$\u003c/span\u003e0.08/kg\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePortland Cement\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cspan\u003e$\u003c/span\u003e0.36/kg\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLime\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cspan\u003e$\u003c/span\u003e0.72/kg\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSand\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cspan\u003e$\u003c/span\u003e0.41/kg\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"2\"\u003eNote \u0026ndash; Average estimated cost of pyrolysis is $0.01/kg - $0.14/kg (Shackley et al., \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). Portland cement (SKU# 1891149), lime (SKU# 1891056), and sand (SKU# 1891344) were obtained from Menards (De Pere, WI).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003ePotential for Use of Filter Media in Constructed Pond Wetland Systems\u003c/p\u003e \u003cp\u003eTo determine the practicality of use of each filter media in an ARTS, the filter media were each given a score and ranked against each other based on an additive scoring system modified from Ballantine and Tanner (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2010\u003c/span\u003e) and Nguyen et al. (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2020\u003c/span\u003e) on important criteria including P-removal potential, likely cost, energy consumption, use of waste materials, and efficacy in real agricultural runoff.\u003c/p\u003e"},{"header":"Results and Discussion","content":"\u003cp\u003eChemical Composition\u003c/p\u003e \u003cp\u003eBased on chemical analysis of the pelletized media, cement and DWTR pellets were a Ca/Mg/Al-based media (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e) primarily consisting of silicon (Si), calcium (Ca), magnesium (Mg), and aluminum (Al). The presence of an Al-based coagulant in the DWTR contributed to the higher Al content in the DWTR pellets. The AMD pellets were Ca/Fe-based media (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e), containing more iron (Fe). Fe-rich hydrated oxides produced from the neutralization of AMD (Sibrell and Tucker \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2012\u003c/span\u003e) resulted in the increased Fe oxide content of the AMD pellets. Reductions in Ca, and Mg in the DWTR and AMD pellets were due to decreased amounts of Portland cement, lime, and sand.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eElemental composition by XRF analysis of cement, modified DWTR\u0026thinsp;+\u0026thinsp;cement binder pellets, and modified AMD residual\u0026thinsp;+\u0026thinsp;cement binder pellets prior to column experiments. LOI\u0026thinsp;=\u0026thinsp;loss on ignition at 1000\u0026deg;C and represents organic matter plus inorganic carbon content.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eCement\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003eDWTR\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003eAMD\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePyrolyzed (CEM-P)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNon-Pyrolyzed (CEM)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePyrolyzed (RCB-P)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNon-Pyrolyzed (RCB)\u003c/p\u003e \u003c/td\u003e 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colname=\"c3\"\u003e \u003cp\u003e2.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e17.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e2.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFe\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e21.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e20.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSO\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eK\u003csub\u003e2\u003c/sub\u003eO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNa\u003csub\u003e2\u003c/sub\u003eO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTiO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eP\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMnO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBaO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSrO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCr\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLOI @ l000\u0026deg;C\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e16.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e24.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e38.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e14.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e19.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"8\"\u003eNote \u0026ndash; CEM\u0026thinsp;=\u0026thinsp;cement binder, CEM-P\u0026thinsp;=\u0026thinsp;cement binder\u0026thinsp;+\u0026thinsp;pyrolysis, RCB\u0026thinsp;=\u0026thinsp;cement binder\u0026thinsp;+\u0026thinsp;DWTR, RCB-P\u0026thinsp;=\u0026thinsp;cement binder\u0026thinsp;+\u0026thinsp;DWTR\u0026thinsp;+\u0026thinsp;pyrolysis, ACB\u0026thinsp;=\u0026thinsp;cement binder\u0026thinsp;+\u0026thinsp;AMD, ACB-P\u0026thinsp;=\u0026thinsp;cement binder\u0026thinsp;+\u0026thinsp;AMD\u0026thinsp;+\u0026thinsp;pyrolysis.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e\u003cp\u003eBreakthrough Experiments using Synthetic Runoff\u003c/p\u003e \u003cp\u003ePyrolysis of media greatly impacted removal capacity of P from synthetic agricultural runoff and the pyrolyzed cement binder pellet (CEM-P) had significantly greater P removal than other media evaluated (2268 mg P/kg media at exhaustion; Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Pyrolysis increased the P removal capacity of the pellets that contained metal residuals across all factors and improved performance 2-fold for CEM and ACB and 17-fold for RCB at exhaustion (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). The performance of the pyrolyzed DWTR pellets were increased due to a reduction in organic matter and an increase in Al oxide (Truong and Kim \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e2021\u003c/span\u003e, Kuster et al. \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2021\u003c/span\u003e; Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e) which increased P removal through adsorption to Al-(hydr-)oxides or precipitation of Al-phosphates (Qin et al. \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Previous studies of Ca based materials (waste concrete; Liu et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2020\u003c/span\u003e) and (seashells; Paradelo et al. \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2016\u003c/span\u003e) noted that pyrolysis increased P removal by oxidizing calcium carbonate into calcium oxide. CEM-P had a higher percent P removal over time and took the longest to exhaust compared to the other non-pyrolyzed pellets (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). CEM-P had the highest P removal capacity (2268 mg P/kg media) but ACB and ACB-P had the highest P removal efficiency (70% and 72% respectively; Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). The cumulative P removal efficiency of CEM-P likely appeared lower due to the longer time to exhaustion (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). ACB and ACB-P were the most efficient before exhaustion compared to the other media but exhausted faster than CEM-P. More ligand exchange occurred with ACB and ACB-P due to the high Fe content (20% and 21% respectively) which caused a faster removal of P but also consumed reactive sites faster than CEM-P (Penn et al., 2017).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePhosphorus removal capacity of each media at pH 6\u0026ndash;1 min retention, cumulative P removal efficiency, and time each media reached 20% exhaustion. Note \u0026ndash; standard deviation in parenthesis. Media with the same letter are not statistically different at α\u0026thinsp;=\u0026thinsp;0.05.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedia\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eID\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003eP Removal Capacity\u003c/p\u003e \u003cp\u003e(mg P/kg media)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCumulative P Removal Efficiency (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eTime (hour)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder (sand, lime, cement)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eCEM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1397 (43) c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e67 (2) bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e240\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eCEM-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2268 (63) e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e54 (1) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e432\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;DWTR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eRCB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e71 (3) a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e34 (3) a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;DWTR\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eRCB-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1178 (55) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e67 (3) bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e144\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;AMD residual\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eACB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1007 (155) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e71 (14) bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e136\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;AMD residual\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eACB-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1685 (4) d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e72 (1) c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e244\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAdditions of AMD and DWTR significantly decreased removal of the non-pyrolyzed cement pellets with the DWTR and cement pellet having the lowest P removed. Decreased performance of the pellets with metal residuals could be caused by decreasing the Ca content (i.e. Portland cement and lime) by adding DWTR and AMD in the pellet mixture. Decreasing the Ca content would lower P removal by decreasing the precipitation of hydroxyapatite which is likely the main removal mechanism (Littler et al., \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). Cement will also immobilize metals (Jo et al., \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2023\u003c/span\u003e), as cement is also used for solidification and stabilization to slow the release of harmful chemicals, which could have also lowered treatment potential of media with metal residuals (i.e. DWTR and AMD). Portland cement and lime in the cement binder mixture will precipitate metals forming insoluble hydroxides with impervious coatings, inhibiting P reactions with the added metals (Cartledge et al., \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e1990\u003c/span\u003e). Future studies pelletizing metal residuals should evaluate other binders (e.g. clays, chitosan) to decrease metal immobilization and increase reactivity.\u003c/p\u003e \u003cp\u003eThe P removal capacity of RCB-P and ACB-P were within the range of other reactive media in flow through column studies including electric arc furnace slag, coal ash, shellsand, and Filtralite PTM (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). However, removal capacities for P of both DWTR and AMD residual pellets were lower than measured removal of raw DWTR and AMD in previous literature (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e), likely as a result of differences in experimental design and physiochemical properties of residuals. The differences in P removal could be influenced by different experimental conditions including initial P concentration, batch vs column experiments, retention time, exhaustion definition, and differences in the physical and chemical composition of DWTR and AMD residual (e.g. Al/Fe content, particle size, surface area).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of P removal capacities (mg P/kg media) between cement binder\u0026thinsp;+\u0026thinsp;DWTR\u0026thinsp;+\u0026thinsp;pyrolysis (RCB-P), cement binder\u0026thinsp;+\u0026thinsp;AMD residual\u0026thinsp;+\u0026thinsp;pyrolysis (ACB-P), and other reactive media in flow through column studies.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFilter Media\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eP Removal Capacity (mg P/kg media)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;DWTR\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1,178\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;AMD residual\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1,685\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eElectric arc furnace slag\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2,200 (Drizo et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2006\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCoal ash\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e300 (Drizo et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e1999\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eShellsand\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e497-3,500 (\u0026Agrave;d\u0026agrave;m et al., \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2007\u003c/span\u003e; Roseth, \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e2000\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFiltralite PTM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e497 (\u0026Agrave;d\u0026agrave;m et al., \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2006\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRaw DWTR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2,000\u0026ndash;43,000 (Muisa et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2020\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRaw AMD residual\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9,890\u0026ndash;31,970 (Wei et al., \u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e2008\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eImpact of pH and Retention Time on P Removal\u003c/p\u003e \u003cp\u003eThe P removal efficiency of the filter media was not significantly impacted by changes in influent water pH except for CEM-P (Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e) due to a lower standard deviation measured for the pH 8 trial. The main P removal mechanisms of the media are likely through hydroxyapatite precipitation reactions of Ca/Mg-phosphate minerals (Supplementary Information Figure S3; Stoner et al., \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). The media has a high pH and buffer capacity that maintained a pH that favors the precipitation of hydroxyapatite regardless of influent pH (Penn et al. \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). Filter media can be deployed to treat agricultural runoff with a pH of 6 and above without impacting P removal.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCumulative P removal efficiency of each media at varying pH (i.e. 6, 8, and 10) with a 1-min retention. Note \u0026ndash; standard deviation in parenthesis. Different letters indicate statistical significance between media for individual conditions (i.e. pH 6, 8, and 10) at α\u0026thinsp;=\u0026thinsp;0.05.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedia\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eID\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003epH 6\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003epH 8\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003epH 10\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder (sand, lime, cement)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCEM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e82 (5) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e80 (15) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e81 (7) bc\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCEM-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e85 (2) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e93 (0.5) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e85 (4) bc\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;DWTR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRCB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e29 (3) a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e27 (4) a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e22 (1) a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;DWTR\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRCB-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e73 (8) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e74 (2) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e77 (6) b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;AMD residual\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eACB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e75 (11) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e91 (6) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e86 (5) bc\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;AMD residual\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eACB-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e88 (3) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e92 (1) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e91 (1) c\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eRetention time greatly impacted P removal efficiency of the media from synthetic agricultural runoff as a result of removal mechanisms. Increasing the retention time from 1- to 5-min significantly increased the P removal efficiency between 8-134%. The filter media benefited from an increased retention time due to hydroxyapatite precipitation, the main hypothesized P-removal mechanism, which removed P slower and is impacted by changes in retention time (Stoner et al., \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). RCB was the only media that had a significant difference between a 5- and 10-min retention time and was the most impacted by increases in retention time (134% increase from 1 to 5-min retention and 26% increase from 5 to 10-min retention; Table\u0026nbsp;\u003cspan refid=\"Tab7\" class=\"InternalRef\"\u003e7\u003c/span\u003e) due to an elevated organic matter content (24%; Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e) which slowed the diffusion of P into micropores which increased treatment potential with increased contact time (Makris et al., \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2005\u003c/span\u003e). ACB-P was least impacted by changes in retention time (8% increase in P removal efficiency from 1 to 5-min retention; Table\u0026nbsp;\u003cspan refid=\"Tab7\" class=\"InternalRef\"\u003e7\u003c/span\u003e) due to a higher content of Fe (20%, Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e), Fe-based materials remove P mostly through ligand exchange reactions which are less impacted by retention time because they occur faster than precipitation reactions (Penn et al., 2017). Pyrolyzed media were also less impacted by increases in retention time than the non-pyrolyzed media which also supports the impact of OM on P removal efficiency. Each media type, especially non-pyrolyzed media, would perform best in treatment systems with longer retention times (between 1\u0026ndash;5 minute) than shorter contact high flow systems.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab7\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 7\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAverage cumulative P removal efficiency (%) of each media at multiple retention times (i.e. 1, 5, and 10 min) treating synthetic runoff at pH 6.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedia\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eID\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1-min retention\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5-min retention\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e10-min retention\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder (sand, lime, cement)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCEM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e82 (5) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e95 (3) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e95 (2) b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCEM-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e85 (2) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e96 (2) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e98 (2) bc\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;DWTR*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRCB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e29 (3) a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e68 (3) a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e86 (1) a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;DWTR\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRCB-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e73 (8) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e96 (1) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e99.7 (0.1) bc\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;AMD residual\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eACB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e75 (11) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e97 (1) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e97 (0.7) bc\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;AMD residual\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eACB-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e88 (3) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e95 (3) b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e98 (0.5) bc\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eNote \u0026ndash; standard deviation in parenthesis. Media with an * are statistically different between 1-, 5-, and 10-min retention at α\u0026thinsp;=\u0026thinsp;0.05, media without an * are statistically different between 1- and 5-min retention. Different letters indicate statistical significance between media for individual conditions (i.e. 1, 5, and 10-min retention) at α\u0026thinsp;=\u0026thinsp;0.05.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eEffectiveness of P Removal from Field-Sourced Agricultural Runoff\u003c/p\u003e \u003cp\u003eField-sourced agricultural runoff decreased the P removal efficiency of each media between 13\u0026ndash;55% compared to synthetic runoff with a 10-min retention. The decreased performance of the media was due to the presence of bicarbonate in the agricultural runoff which can form calcite minerals and reduce P removal by clogging the pore structure (Penn et al., \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Even with a decreased efficacy of P removal, these media still have significant potential to remove P from agricultural runoff in edge of field treatment systems. RCB-P had similar P removal efficiencies as CEM and CEM-P (77%, 78%, and 85% respectively; Table\u0026nbsp;\u003cspan refid=\"Tab8\" class=\"InternalRef\"\u003e8\u003c/span\u003e). CEM-P was the least impacted by field-sourced agricultural runoff (13% decrease) and RCB was most impacted (55% decrease) which is correlated with how well the media performed overall (i.e. CEM-P had higher P removal than RCB at each factor). The filter media was not run to exhaustion with real agricultural runoff and should be considered for future studies. Before being considered for field deployment, P removal capacities of filter media should be investigated at faster flow rates (i.e. between 1- to 5-min retention) to determine optimal retention times.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab8\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 8\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAverage cumulative P removal efficiency (%) of each media treating agricultral runoff with a 10-min retention. Note \u0026ndash; standard deviation in parenthesis and media with the same letter are not statistically different at α\u0026thinsp;=\u0026thinsp;0.05.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedia\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eID\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10-min retention\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder (sand, lime, cement)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCEM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e78 (8) c\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCEM-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e85 (6) c\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;DWTR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRCB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e39 (1) a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;DWTR\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRCB-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e77 (4) c\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;AMD residual\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eACB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e54 (7) ab\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;AMD residual\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eACB-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e68 (11) bc\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e\n\u003ch3\u003eCost Estimate of Filter Media\u003c/h3\u003e\n\u003cp\u003eCEM-P was the least costly media, costing \u003cspan\u003e$\u003c/span\u003e1,936 to treat 10.1 ha with a load of 7 kg P and would require the least amount of material (3,488 kg; Table\u0026nbsp;\u003cspan refid=\"Tab9\" class=\"InternalRef\"\u003e9\u003c/span\u003e). The least costly media that included a waste product was ACB-P, which would cost slightly more than CEM-P (\u003cspan\u003e$\u003c/span\u003e2,159) but would require more mass to treat the same amount of runoff (5,442 kg; Table\u0026nbsp;\u003cspan refid=\"Tab9\" class=\"InternalRef\"\u003e9\u003c/span\u003e). CEM-P had a higher P removal capacity and a lower percent inefficiency at agricultural runoff treatment than ACB-P which resulted in less mass being required for treatment but was only slightly less costly than ACB-P because ACB-P required less Portland cement, lime, and sand due to containing a waste product (i.e. AMD residual). Pyrolyzed media (i.e. CEM-P, RCB-P, and ACB-P) are less costly than the non-pyrolyzed media (i.e. CEM, RCB, and ACB) due to a higher P removal capacity (less mass required to remove the same amount of P). Other best management practices (BMPs) are less costly to treat the same amount of P (7 kg) including buffer strips (\u003cspan\u003e$\u003c/span\u003e562-\u003cspan\u003e$\u003c/span\u003e700; Balana et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2012\u003c/span\u003e), minimum tillage (\u003cspan\u003e$\u003c/span\u003e316; Haygarth et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2009\u003c/span\u003e), injection (\u003cspan\u003e$\u003c/span\u003e1,349; Haygarth et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2009\u003c/span\u003e), incorporation (\u003cspan\u003e$\u003c/span\u003e123; Haygarth et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2009\u003c/span\u003e), and cover cropping (\u003cspan\u003e$\u003c/span\u003e538; Haygarth et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). The estimated costs of these BMPs could underestimate the true cost due to limitations of the models used, not including all associated costs, inflation, and could vary based on soil type and landscape of the treatment area. Filter media may be more expensive than other BMPs but has measurable treatment by having the ability to test runoff before and after flowing through the filter media (beneficial to nutrient trading), promotes a circular economy if it contains a waste product, and reduces the added expense of agricultural machinery and time to implement these practices.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab9\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 9\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMass and cost of filter media required to treat the example ARTS.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedia\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eID\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMass\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eCost\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCEM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5,913 kg or 585 kg/ha\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cspan\u003e$\u003c/span\u003e2,809 or \u003cspan\u003e$\u003c/span\u003e278/ha\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCEM-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3,488 kg or 345 kg/ha\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cspan\u003e$\u003c/span\u003e1,936 or \u003cspan\u003e$\u003c/span\u003e192/ha\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;DWTR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRCB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e152,817 kg or 15,130 kg/ha\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cspan\u003e$\u003c/span\u003e48,392 or \u003cspan\u003e$\u003c/span\u003e4,791/ha\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;DWTR\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRCB-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7,291 kg or 722 kg/ha\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cspan\u003e$\u003c/span\u003e2,892 or \u003cspan\u003e$\u003c/span\u003e286/ha\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;AMD residual\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eACB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10,010 kg or 991 kg/ha\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cspan\u003e$\u003c/span\u003e3,170 or \u003cspan\u003e$\u003c/span\u003e314/ha\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;AMD residual\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eACB-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5,442 kg or 539 kg/ha\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cspan\u003e$\u003c/span\u003e2,159 or \u003cspan\u003e$\u003c/span\u003e214/ha\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003ePotential for Use of Filter Media in Constructed Pond Wetland Systems\u003c/p\u003e \u003cp\u003eBased on an additive scoring system modified from Ballantine and Tanner (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2010\u003c/span\u003e) and Nguyen et al. (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2020\u003c/span\u003e), CEM, CEM-P, RCB-P, and ACB were the most practical media (Table\u0026nbsp;\u003cspan refid=\"Tab10\" class=\"InternalRef\"\u003e10\u003c/span\u003e) to be used in a constructed pond wetland system but they each have different benefits and drawbacks. CEM was low cost (\u003cspan\u003e$\u003c/span\u003e2,809; Table\u0026nbsp;\u003cspan refid=\"Tab9\" class=\"InternalRef\"\u003e9\u003c/span\u003e), had a high potential to remove P from agricultural runoff, and a medium P removal capacity but did not use a waste product and had a medium energy consumption due to the energy required to make the Portland cement and lime. CEM-P was also low cost (\u003cspan\u003e$\u003c/span\u003e1,936), had a high P removal capacity, and high potential to remove P from agricultural runoff but did not use a waste product and had high energy consumption due to the pellet components and the energy required for pyrolysis. RCB-P was low cost (\u003cspan\u003e$\u003c/span\u003e2,892), contained a waste product (33% DWTR), had high potential to remove P from agricultural runoff, and had a medium P removal capacity but had a high energy consumption due to the energy required for pyrolysis. ACB was low cost (\u003cspan\u003e$\u003c/span\u003e3,170), used a waste material (33% AMD residual), had a low energy consumption due to needing a decreased amount of Portland cement and lime and was not pyrolyzed, had a medium P removal capacity but had a low potential to remove P from agricultural runoff. RCB was the least practical media tested due to having a high cost to deploy (\u003cspan\u003e$\u003c/span\u003e48,392), and low P removal (34% P removal efficiency of synthetic runoff at 20% exhaustion and 39% P removal efficiency of agricultural runoff) even though this media had a low energy consumption and used a waste product (33% DWTR).\u003c/p\u003e \u003cp\u003eThe filter media have the potential to be used as a permeable concrete to remove P from agricultural runoff. Previous studies of permeable concrete have been shown to remove pollutants, including P, from stormwater runoff (Wu et al. \u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). The P removal of ordinary permeable concrete can be improved by replacing gravel or sand, which are used as an aggregate, with other materials that have a higher P removal (Wu et al. \u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Permeable concrete containing fly ash (Jo et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2015\u003c/span\u003e), iron oxide (V\u0026aacute;zquez-Rivera et al. \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e2015\u003c/span\u003e), and ordinary Portland cement (Agyei et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2002\u003c/span\u003e) have increased the P removal of ordinary pervious concrete. Quan et al (\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2024\u003c/span\u003e) modified permeable concrete, which normally consists of gravel and cement-based materials, by replacing gravel with industrial solid wastes (i.e. fly ash and granulated blast furnace slag) and achieved a phosphorus removal capacity of 88.93 mg/g. Future studies should be conducted to evaluate the use of heat treated DWTR and AMD pellets in permeable cement.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab10\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 10\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eFilter media score for use in an ARTS.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedia\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eID\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eP-Removal Potential\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLikely Cost\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eEnergy Consumption\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eEfficacy in Real Agricultural Runoff\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eUse of Waste Materials\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCEM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMedium\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLow\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eMedium\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eHigh\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eLow\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCEM-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eHigh\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLow\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eHigh\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eHigh\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eLow\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;DWTR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRCB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eLow\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eHigh\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eLow\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eLow\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eMedium\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;DWTR\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRCB-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMedium\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLow\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eHigh\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eHigh\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eMedium\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;AMD residual\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eACB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMedium\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLow\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eLow\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eLow\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eMedium\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCement binder\u0026thinsp;+\u0026thinsp;AMD residual\u0026thinsp;+\u0026thinsp;pyrolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eACB-P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMedium\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLow\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eHigh\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eLow\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eMedium\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"8\"\u003eNote \u0026ndash; Score determined by addition. P-removal potential: low\u0026thinsp;=\u0026thinsp;1, medium\u0026thinsp;=\u0026thinsp;2, high\u0026thinsp;=\u0026thinsp;3; Likely cost: low\u0026thinsp;=\u0026thinsp;3, medium\u0026thinsp;=\u0026thinsp;2, high\u0026thinsp;=\u0026thinsp;1; Energy consumption: low\u0026thinsp;=\u0026thinsp;3, medium\u0026thinsp;=\u0026thinsp;2, high\u0026thinsp;=\u0026thinsp;1; Efficacy in real agricultural runoff: low\u0026thinsp;=\u0026thinsp;1, medium\u0026thinsp;=\u0026thinsp;2, high\u0026thinsp;=\u0026thinsp;3; Use of waste material: low\u0026thinsp;=\u0026thinsp;1, medium\u0026thinsp;=\u0026thinsp;2, high\u0026thinsp;=\u0026thinsp;3.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eModified DWTR and AMD residual have the potential to be used as a filter media to remove P in a constructed pond wetland system. Pyrolysis of the media and increased retention time (5-min) had positive impacts on P removal while adding DWTR and AMD to the cement binder decreased P removal. Agricultural runoff decreased the performance of the filter media compared to synthetic runoff. CEM-P is the least costly material and requires the least amount of material for field scale deployment at a constructed pond wetland system. Future studies should evaluate the use of other binding materials and determine the optimal retention time between 1- to 5-min retention.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eAcknowledgements\u003c/p\u003e\n\u003cp\u003eThe authors would like to acknowledge Dr. Joseph Sanford (University of Wisconsin \u0026ndash; Platteville), Paul Reneau (USGS), Jeremy Freund (Outagamie County), Dr. Kevin Fermanich (University of Wisconsin \u0026ndash; Green Bay), Dr. Chad Penn (USDA), Holly lab students (University of Wisconsin \u0026ndash; Green Bay), Green Bay Water Utility, and Heart of the Valley Metropolitan Sewerage District. \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFunding\u003c/p\u003e\n\u003cp\u003eThis work is supported by Capacity Building Grants for Non-Land-Grant Colleges of Agriculture Program [USDA-NIFA-NLGCA-009505] from the USDA National Institute of Food and Agriculture.\u003c/p\u003e\n\u003cp\u003eAuthors Contributions\u003c/p\u003e\n\u003cp\u003eBeth Kondro: experimentation; analysis; writing; original draft preparation; Michael Holly: methodology; analysis; writing; review and editing\u003c/p\u003e\n\u003cp\u003eEthical Approval\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003eConsent to Participate\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003eConsent to Publish\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003eCompeting Interests\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003eData Availability Statement\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003e\u0026Agrave;d\u0026agrave;m K, S\u0026oslash;vik AK, Krogstad T (2006) Sorption of phosphorous to Filtralite-P \u0026reg;\u0026mdash;the effect of different scales. Water Res 40:1143\u0026ndash;1154\u003c/li\u003e\n\u003cli\u003e\u0026Agrave;d\u0026agrave;m K, Krogstad T, Vr\u0026aring;le L, S\u0026oslash;vik AK, Jenssen PD (2007) Phosphorus retention in the filter materials shellsand and Filtralite P \u0026reg;\u0026mdash;batch and column experiment with synthetic P solution and secondary wastewater. Ecol Eng 29:200\u0026ndash;208.\u003c/li\u003e\n\u003cli\u003eAhmad T, Ahmad K, Alam M (2016) Characterization of water treatment plant\u0026rsquo;s sludge and its safe disposal options. Procedia Environ Sci 35:950\u0026ndash;955.\u003c/li\u003e\n\u003cli\u003eAgyei NM, Strydom CA, Potgieter JH (2002) The removal of phosphate ions from aqueous solution by fly ash, slag, ordinary Portland cement and related blends. 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J Clean Prod 278:. https://doi.org/10.1016/j.jclepro.2020.123933\u003c/li\u003e\n\u003cli\u003eZou J, Xu G, Pan K, Zhou W, Dai Y, Wang X, Zhang D, Hu Y, Ma M (2012) Nitrogen removal and biofilm structure affected by COD/NH4+\u0026ndash;N in a biofilter with porous sludge-ceramsite. Sep Purif Technol 94:9-15. https://doi.org/10.1016/j.seppur.2012.03.019.\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":true,"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":"Filter media, cement binder pellet, phosphorus removal, agricultural runoff, drinking water treatment residual, acid mine drainage residual, constructed wetland","lastPublishedDoi":"10.21203/rs.3.rs-6347283/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6347283/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eSoil phosphorus (P) losses through agricultural runoff and tile drainage can lead to eutrophication of water resources. Drinking water treatment residual (DWTR) and acid mine drainage residual (AMD) have the ability to remove P but lack mechanical strength and a uniform particle size. Previous studies of DWTR and AMD consisted primarily of batch trials and measurement of P removal using flow-through columns, utilizing real agricultural runoff, would be beneficial to scalability. We modified DWTR and AMD through pelletization and pyrolysis and evaluated P removal using flow-through columns under different conditions (i.e. retention time, pH, and agricultural runoff). Pyrolysis increased P removal of the media pellets 2 to 17-fold. Filter media performance benefited from longer retention times and P removal efficiency increased 8-134% when retention time was increased from 1- to 5- min. Cost estimate and practicality for field deployment in a constructed pond wetland system were evaluated for each media. Cement binder\u0026thinsp;+\u0026thinsp;pyrolysis (CEM-P), cement binder (CEM), cement binder\u0026thinsp;+\u0026thinsp;DWTR\u0026thinsp;+\u0026thinsp;pyrolysis (RCB-P), and cement binder\u0026thinsp;+\u0026thinsp;AMD (ACB) were the most practical media for field deployment. The top 3 least costly media were CEM-P (\u003cspan\u003e$\u003c/span\u003e1,936), cement binder\u0026thinsp;+\u0026thinsp;AMD\u0026thinsp;+\u0026thinsp;pyrolysis (ACB-P; \u003cspan\u003e$\u003c/span\u003e2,159), and CEM (\u003cspan\u003e$\u003c/span\u003e2,809).\u003c/p\u003e","manuscriptTitle":"Reactive cement pellet media including drinking water treatment and mine drainage residuals for phosphorus removal in agricultural runoff","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-08 07:09:27","doi":"10.21203/rs.3.rs-6347283/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":"590d91fa-63e8-4679-9264-fa783e7b155e","owner":[],"postedDate":"May 8th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-10-16T18:31:43+00:00","versionOfRecord":[],"versionCreatedAt":"2025-05-08 07:09:27","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6347283","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6347283","identity":"rs-6347283","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}