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The nitrogen (N) release from composted and un-composted biosolids and plant available N (PAN) of the biosolids were quantified to evaluate if composting can contribute to stabilize biosolids N and reduce the nitrate ( NO 3 - ) leaching potential in biosolids-amended soil. Biosolids were composted at >55°C for 21 days after mixing the biosolids with yard waste at 1:1 (w/w) ratio. In the N release study, we installed field lysimeters filled with soil (sand and clay) amended with composted and un-composted biosolids at two rates (30 and 150 dry Mg/ha) and measured the inorganic N in leachate after each rainfall and soil inorganic N monthly. The N released from composted biosolids during the two-year study period were lower (6% of organic N added for clay and 11% for sandy loam soil) as compared to un-composted biosolids (14% of organic N added for clay and 21% for sandy soils). Composted biosolids showed a lower N release rate constant k value of 0.0014 and 0.0027 month-1 for clay and sandy soil, respectively, compared to corresponding values of 0.0035 and 0.0068 month-1 for un-composted biosolids. We used greenhouse bioassay with corn (Zea mays), ryegrass (Lolium perenne), and Miscanthus (Miscanthus giganteus) as test plants grown for six months with reference to N chemical fertilizer ranging from 0, 75, 150 to 300 kg N/ha to evaluate the PAN of the biosolids. Based on our study, plant growth was not affected by using either composted or un-composted biosolids but the PAN was lower in composted biosolids (4.0%-5.9%) than un-composted biosolids (11.4%-13.6%). Composting results in higher N-retention efficiency in biosolids and composted biosolids are a valuable source of N to support the plant growth with lower N released to the environment. Thus, the potential of N leaching would still be low in the situations where a high rate of biosolids needs to be applied for land reclamation or landscaping soil reconstruction. PRACTITIONER POINTS: Composting enhances N-retention efficiency in biosolids and composted biosolids are a valuable source of N to support the plant growth with lower N released to the environment. Potential of N leaching would still be low in the situations where a high rate of biosolids needs to be applied for land reclamation or landscaping soil reconstruction. N released from composted and un-composted biosolids can be adequately described by first-order kinetic model.

The former US Steel Corporation's South Works site in Chicago, IL, is a 230-ha bare brownfield consisting of steel mill slag fill materials that will need to be reclaimed to support and sustain vegetation. We conducted a case study to evaluate the suitability of biosolids and dredged sediments for capping the steel mill slag to establish good quality turfgrass vegetation. Eight study plots were established on a 0.4-ha parcel that received biosolids and dredged sediment blends of 0, 25, 50, or 100% biosolids (v/v). Turfgrass was successfully established and was thicker and greener in biosolids-amended sediments than in unamended sediments. Concentrations of N, P, K, and micronutrients in turfgrass tissues increased with increasing biosolids. Soil organic carbon, N, P, and micronutrients increased with increasing biosolids. Cadmium, Cu, Ni, and Zn concentrations in biosolids-amended sediments also increased with increasing biosolids but were far below phytotoxicity limits for turfgrass. Lead and Cr concentrations in biosolids-amended plots were comparable to concentrations in unamended sediments. Groundwater monitoring lysimeters and wells below the study site and near Lake Michigan were not affected by nutrients leaching from the amendments. Overall, the results from this case study demonstrated that blends of biosolids and dredged sediments could be successfully used for capping steel mill slag brownfield sites to establish good quality turfgrass vegetation.

Large tracts of abandoned urban land, resulting from the deindustrialization of metropolitan areas, are generating a renewed interest among city planners and community organizations envisioning the productive use of this land not only to produce fresh food but to effectively manage stormwater and mitigate the impact of urban heat islands. Healthy and productive soils are paramount to meet these objectives. However, these urban lands are often severely degraded due to anthropogenic activities and are generally contaminated with priority pollutants, especially heavy metals and polycyclic aromatic hydrocarbons. Characterizing these degraded and contaminated soils and making them productive again to restore the required ecosystem services was the theme of the "Soil in the City- 2014" conference organized by W-2170 Committee (USDA's Sponsored Multi-State Research Project: Soil-Based Use of Residuals, Wastewater, & Reclaimed Water). This special section of comprises 12 targeted papers authored by conference participants to make available much needed information about the characteristics of urban soils. Innovative ways to mitigate the risks from pollutants and to improve the soil quality using local resources are discussed. Such practices include the use of composts and biosolids to grow healthy foods, reclaim brownfields, manage stormwater, and improve the overall ecosystem functioning of urban soils. These papers provide a needed resource for educating policymakers, practitioners, and the general public about using locally available resources to restore fertility, productivity, and ecosystem functioning of degraded urban land to revitalize metropolitan areas for improving the overall quality of life for a large segment of a rapidly growing urban population.

Pharmaceutical and personal care product compounds (PPCPs) comprise a large and diverse group of chemical compounds, including prescription and over-the-counter drugs and cleaning agents. Although PPCPs in the effluent and biosolids of water resource recovery facilities (WRRFs) are currently not regulated, public interest has led the Metropolitan Water Reclamation District of Greater Chicago to monitor for 11 PPCPs in the influent, effluent, and biosolids at its seven WRRFs. In 2016, the U.S. Food and Drug Administration (FDA) issued a final rule establishing that 19 specific ingredients, including triclosan and triclocarban, were no longer generally recognized as safe and effective, which prohibits companies from marketing soaps as antibacterial if they contain one or more of these ingredients. It was presumed that since the proposed rulemaking in 2013, manufacturers began to remove these active ingredients from their products. Annual monitoring of 11 PPCPs from 2012 to 2017 demonstrated a 71% decrease in triclosan and 72% decrease in triclocarban in per capita influent loading into seven WRRFs. There was a 70% decrease in triclosan and 80% decrease in triclocarban concentrations in biosolids. These declines suggest the FDA rule for the reduction in use of these compounds was effective and resulted in manufacturers removing these ingredients from their products. PRACTITIONER POINTS: Reduction in triclosan and triclocarban per capita influent loading observed from 2012 to 2017. Reduction in triclosan and triclocarban biosolids loading observed from 2012 to 2017. 2016 FDA rulemaking on antimicrobial soaps was effective in removing triclosan and triclocarban from these products. Positive impact on quality of biosolids land applied to farmland.

Promulgation of the Clean Water Act (CWA) authorized the United States Environmental Protection Agency (U.S. EPA) to regulate quality standards for surface waters and establish regulations limiting the amounts and types of pollutants entering the nation's waters. U.S. EPA imposed national pretreatment standards on industrial wastes discharged to the collection systems of publicly owned treatment works (POTWs) and promulgated General Pretreatment Regulations in 1978. This study analyzed trace metals data from the National Sewage Sludge Surveys conducted by U.S. EPA and the American Metropolitan Sewage Agencies (AMSA) to evaluate the effect of implementation of the national industrial pretreatment standards on concentrations of trace metals in sludges generated by POTWs in the United States. The data showed that implementation of pretreatment programs has been highly effective in reducing the amount of pollutants that enter POTWs and has resulted in a substantial reduction in the levels of trace metals in the municipal sludges. Concentrations of chromium, lead, and nickel in sludge declined by 78, 73, and 63%, respectively, within a year after promulgation of General Pretreatment Regulations. Resulting from these measures, metal concentrations in the sludges generated by a majority of POTWs in the United States are sufficiently low that the sludges can be classified as biosolids and also meet the U.S. EPA's exceptional quality criteria for trace metals in biosolids. This improvement gives POTWs the option to use their biosolids beneficially through land application.

Many soils at former industrial sites are degraded. The objective of this research was to determine the ability of compost, biosolids, and biosolids blends to improve soil ecosystem function with minimal potential impact to surface water. Treatments rototilled into the top 12.5 cm of soil were biosolids at 202 Mg ha; biosolids at 404 Mg ha; compost at 137 Mg ha; or a blend consisting of biosolids applied at 202 Mg ha, drinking water treatment residual, and biochar. Rainfall runoff from experimental plots was collected for 3 yr. One year after soil amendments were incorporated, a native seed mix containing grasses, legumes, and forbs was planted. Soil amendments improved soil quality and nutrient pools, established a dense and high-quality vegetative cover, and improved earthworm reproductive measures. Amendments increased soil enzymatic activities that support soil function. Biosolids treatments increased the Shannon-Weaver Diversity Index for grasses. For the forbs group, control plots had the lowest diversity index and the biosolids blend had the highest diversity index. Biosolids and compost increased the number of earthworm juveniles. In general, biosolids outperformed compost. Biosolids increased N and P in rainfall runoff more than compost before vegetation was established. Several microconstituents (i.e., pharmaceutical and personal care products) were detected in runoff water but at concentrations below the probable no-effect levels and therefore should pose little impact to the aquatic environment. Future restoration design should ensure that runoff control measures are used to control sediment loss from the restored sites at least until vegetation is established.

Detectable levels of dioxins have been reported in biosolids, but very little information is available on the effect of long-term application of biosolids on dioxins accumulation in soil and uptake by plants. We analyzed dioxins in soil and corn tissue samples from field plots after 30 continuous applications of biosolids at 0 (Control), 16.8, and 67.2 Mg biosolids ha(-1) yr(-1) resulting in 0, 504, and 2016 Mg ha(-1) cumulative loadings of biosolids, respectively. The levels of dioxins in soil were only 79.9, 115.5, and 247.5 ng toxic equivalents (TEQs) kg(-1) in the 0, 504, and 2016 Mg biosolids ha(-1) plots, respectively. Dioxins were not detected in the corn grain, and only trace levels (6.8-7.5 ng TEQs kg(-1)) were found in the corn stover; however, these values were not statistically different between control and biosolids-amended soils. These observations suggest that although long-term application of biosolids may increase the levels of dioxins in soil, it does not affect dioxins uptake by corn.

Significant concentrations of chlorinated pesticides such as 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) and its two main transformation products, 1,1-dichloro-2,2-bis(4-chlorophenyl)ethane (DDD) and 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (DDE) are still present in soil and sediment systems more than 30 years after DDT use was banned in the United States. DDT enters waterways via the runoff from industrial point sources, agricultural lands and atmospheric deposition. We evaluated zero-valent iron (Fe 0 ), ferrous sulfide (FeS), as well as combining them with hydrogen peroxide (H 2 O 2 ) as viable treatment technologies for degrading DDT in an aqueous solution. Treatment of DDT with Fe 0 and FeS resulted in approximately 88% and 56% transformation of DDT within 150 h, respectively. DDE production was insignificant in all systems. The DDT removal was slower with FeS than with Fe 0 , but the amounts of DDD and DDE produced did not exceed baseline. Treatment with a 1:1 mixture of Fe 0 –FeS removed about 95% of the added mass of DDT within 4 days and generated significant amounts of DDD and minor amounts of DDMU. When small amounts of H 2 O 2 were introduced halfway through the Fe 0 and FeS treatment times, the mass of DDT decreased by 87% and 96%, respectively, within 2 days. Our results demonstrate that mixtures of Fe 0 –FeS in combination with H 2 O 2 can be used for rapid and efficient removal of DDT from aqueous solutions.

This study was conducted to estimate nitrogen (N) mineralization of anaerobically digested centrifuge cake from the Stickney Water Reclamation Plant (SWRP) and Calumet Water Reclamation Plant (CWRP), lagoon-aged air-dried biosolids from the CWRP, and Milorganite at three rates of application (0, 12.5 and 25 Mg ha(-1)). The N mineralized varied among biosolids as follows: Milorganite (44%) > SWRP centrifuge cake (35%) > CWRP centrifuge cake (31%) > aged air-dried (13%). The N mineralized in the SWRP cake (32%) and CWRP aged air-dried biosolids (12%) determined from the 15N study were in agreement with the first study. The N mineralization value for centrifuge cake biosolids observed in our study is higher than the value given in the Part 503 rule and Illinois Part 391 guidelines. These results will be used to fine-tune biosolids application rate to match crop N demand without compromising yield while minimizing any adverse effect on the environment.

Topsoil removal, compaction, and other practices in urban and industrial landscapes can degrade soil and soil ecosystem services. There is growing interest to remediate these for recreational and residential purposes, and urban waste materials offers potential to improve degraded soils. Therefore, the objective of this study was to compare the effects of urban waste products on microbial properties of a degraded industrial soil. The soil amendments were vegetative yard waste compost (VC), biosolids (BioS), and a designer mix (DM) containing BioS, biochar (BC), and drinking water treatment residual (WTR). The experiment had a completely randomized design with following treatments initiated in 2009: control soil, VC, BioS-1 (202 Mg ha(-1)), BioS-2 (403 Mg ha(-1)), and DM (202 Mg BioS ha(-1) plus BC and WTR). Soils (0-15-cm depth) were sampled in 2009, 2010, and 2011 and analyzed for enzyme activities (arylsulfatase, β-glucosaminidase, β-glucosidase, acid phosphatase, fluorescein diacetate, and urease) and soil microbial community structure using phospholipid fatty acid analysis (PLFA). In general, all organic amendments increased enzyme activities in 2009 with BioS treatments having the highest activity. However, this was followed by a decline in enzyme activities by 2011 that were still significantly higher than control. The fungal PLFA biomarkers were highest in the BioS treatments, whereas the control soil had the highest levels of the PLFA stress markers (P 0.10). In conclusion, one-time addition of VC or BioS was most effective on enzyme activities; the BioS treatment significantly increased fungal biomass over the other treatments; addition of BioS to soils decreased microbial stress levels; and microbial measures showed no statistical differences between BioS and VC treatments after 3 years of treatment.

Soils surrounding former munitions production facilities are highly contaminated with 2,4,6-trinitrotoluene (TNT). Long-term availability and fate of TNT and its transformation products must be understood to predict environmental impact and develop appropriate remediation strategies. Sorption and transport in surface soil containing solidphase TNT are particularly critical, since nonlinear sorption isotherms indicate greater TNT availability for transport at high concentrations. Our objectives were to determine long-term sorption and bound residue formation in surface and subsurface Sharpsburg soil (Typic Argiudoll). Prolonged equilibration of ¹⁴C-TNT with the soil revealed a gradual increase in amount sorbed and formation of unextractable (bound) ¹⁴C residues. The presence of solid-phase TNT did not initially affect the amount of ¹⁴C sorbed during a 168-d equilibration. After 168 d, 93% of the added ¹⁴C was sorbed by uncontaminated soil, while 79% was sorbed by soil containing solid-phase TNT. In the absence of solid phase, pools of readily available (extractable with 3 mM CaCl₂) and potentially available (CH₃CN-extractable) sorbed TNT decreased rapidly with time and coincided with increased ¹⁴C in soil organic matter. More ¹⁴C was found in fulvic acid than in the humic acid fraction when no solid-phase TNT was present. After sequential extractions, including strong alkali and acid, 32 to 40% of the sorbed ¹⁴C was irreversibly bound (unextractable) in Sharpsburg surface and subsurface soil. Results provide strong evidence for humification of TNT in soil. This process may represent a significant route for detoxification in the soil-water environment. Publication no. 11551, Agric. Res. Div., Univ. of Nebraska — Lincoln, Lincoln, NE 68583-0915.

Past disposal practices at munitions production plants have contaminated terrestrial and aquatk ecosystems with 2,4,6-trinitrotoluene (TNT). We determined TNT transport, degradation, and long-term sorption characteristics in soil. Transport experiments were conducted with repacked, unsaturated soil columns containing uncontaminated soil or layers of contaminated and uncontaminated soil. Uncontaminated soil columns received multiple pore volumes (22-50) of a TNT-{sup 3}H{sub 2}O pulse, containing 70 or 6.3 mg TNT L{sup -1} at a constant pore water velocity. TNT breakthrough curves (BTCs) never reached initial solute pulse concentrations. Apex concentrations (C/C{sub o}) were between 0.6 and 0.8 for an initial pulse of 70 mg TNT L{sup -1} and 0.2 to 0.3 for the 6.3 mg TNT L{sup -1} pulse. Earlier TNT breakthrough was observed at the higher pulse concentration. This mobility difference was predicted from the nonlinear adsorption isotherm determined for TNT sorption. In all experiments, a significant fraction of added TNT was recovered as amino degradates of TNT. Mass balance estimates indicated 81% of the added TNT was recovered (as TNT and amino degradates) from columns receiving the 70 mg TNT L{sup -1} pulse compared to 35% from columns receiving the 6.3 mg TNT L{sup -1} pulse. Most of the unaccountable TNT wasmore » hypothesized to be unextractable. This was supported by a 168-d sorption experiment, which found that within 14d, 80% of {sup 14}C activity (added as {sup 14}C-TNT) was adsorbed and roughly 40% unextractable. Our observations illustrate that TNT sorption and degradation are concentration-dependent and the assumptions of linear adsorption and adsorption-desorption singularity commonly used in transport modeling, may not be valid for predicting TNT transport in munitions-contaminated soils. 29 refs., 6 figs., 7 tabs.« less

Biosolids-borne trace elements may be released to the environment when biosolids are used as fertilizers in farm land. Trace element leachate concentrations from biosolids are known to be limited by both organic and inorganic sorbent surfaces; this experimental evidence has not been previously verified with geochemical modeling of sorption reactions. In this study, pH-dependent leaching experiments and sorption isotherm experiments were coupled with a multisurface geochemical modeling approach. Biosolids samples were obtained from Toledo and Chicago wastewater treatment plants; their sorbent surfaces were defined and modeled as a combination of organic matter (OM) and Fe-, Al-, and Mn-oxides. The multisurface geochemical modeling approach was partially successful in predicting the pH-dependent leachate concentrations of As, Cd, Cr, Cu, Mo, Ni, and Zn. Both modeled and experimental data indicated that As and Mo in biosolids were bound to Fe- oxides; Cd, Cr, and Cu were bound mainly to OM; and as pH increased the fractions of Cd and Cu bound to Fe- oxides in the biosolids matrix increased. Ni and Zn were distributed between OM and Fe- oxides, and the percentage of each fraction depended on the pH. This study showed that the multisurface geochemical model could be used to generate As (and to a lesser extent Cd) Freundlich isotherm parameters for biosolids. However, the composition and reactivity of solid and dissolved OM was identified as a source of uncertainty in the modeling results. Therefore, more detailed studies focusing on the reactivity of isolated biosolids OM fractions with regard to proton and metal binding are needed to improve the capability of geochemical models to predict the fate of biosolids-borne trace metals in the environment. QC 20101129

Soil solution chemistry influences the sorption and transport behavior of hydrophobic organic compounds (HOCs) in soil. We used both batch and column studies to investigate the influence of ionic strengths (0.03 and 1.5 M) and flow velocities (12 and 24 cm h-1) on sorption and transport of naphthalene (NAP) in aggregated soil. Sorption parameters such as the Freundlich coefficient (Kf) and exponent (n) calculated from batch studies and column experiments were also compared. Retardation of NAP transport was greater at higher solution ionic strength, which may be attributed to greater sorption affinity due to enhanced aggregation of the sorbent. The effect of ionic strength on sorption of NAP observed in the batch study was consistent with the results from the column study. The Kf and n values obtained from the batch study for the two ionic strengths ranged from 7.8 to 13.7 and 0.68 to 0.80, respectively, whereas the Kf and n values obtained from the column study ranged from 7.9 to 9.9 and 0.73 to 0.85, respectively. The effluent breakthrough curve (BTC) of NAP at a flow rate of 24 cm h-1 showed significant chemical and physical nonequilibrium behavior, implying that a considerable amount of sorption in aggregated soil was time dependent when flow was relatively fast. The BTCs calculated with the parameters determined from batch studies compared poorly with the measured BTCs. The potential for nonequilibrium transport should be incorporated in models used for predicting the fate and transport of HOCs. Furthermore, caution is required when extrapolating the results from batch studies, especially for aggregated soils.