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The application of organic amendments to agricultural soils enables the recycling of nutrients, further reducing the inputs of synthetic fertilizers for crop production. However, the production of N2O emissions is a concern that arises from such a practice. A 35 d incubation experiment was conducted with soils receiving three contrasting types of biosolids — mesophilic anaerobic digested (BM), composted (BC), and alkaline-stabilized (BA) — at four water-filled pore spaces (WFPS): 28%, 40%, 52%, and 64%. A zero-N-addition control was also evaluated. Across all the three types of biosolids, N2O production increased with soil moisture content, with BM and BC producing the overall highest N2O fluxes. The most intense pulses of N2O production were exhibited by BC at the beginning of the incubation. The highest cumulative N2O production was found with 64% WFPS and from BC- (409 μg N2O–N·kg−1 soil) or BM-amended soils (390 μgN2O–N·kg−1 soil), which produced more than four and two times the emissions from the control and BA-amended soils at 64% WFPS, respectively. We also found the highest nitrification rates in the BM- and BC-amended soils. The total N2O production was exponentially associated with the NO3−–N concentration present at the end of the experiment (R2 = 0.83). Changes in the concentration of the soil available N indicated the occurrence of mineralization, nitrification, and denitrification over the incubation. These results provided insight into the interacting responses of N2O production to soil moisture contents, biosolids treatment stabilization and properties, and soil N availability.

Acidification and metal mobility may present challenges in soil receiving paper mill biosolids (PB). Co-applying biochar and PB could help prevent these issues, but its effect must be assessed. The objective of this 224 d incubation study was to evaluate the effect of amending two acidic soils, a clay and sandy loam, with two PB types varying in pH (PB1, pH = 7.80; and PB2, pH = 4.51) co-applied with three rates (0%, 2.5%, and 5% w/w) of pine (Pinus strobus L.) biochar on soil pH and macro- (P, K, Ca, and Mg) and micronutrients (Cu, Zn, Fe, and Mn). In both soils, co-applying biochar and PB significantly increased soil pH and extractable K concentration compared with PB-only application, whereas amending with PB significantly increased soil extractable P concentration compared with the unamended soil. In comparison with PB only, co-applying 5% biochar and PB decreased extractable Cu concentration in both soils and extractable Fe concentration in the sandy loam soil. This study showed that co-applying biochar and PB can be more beneficial to agricultural soils than application of PB alone by supplying nutrients and helping prevent metal toxicity by raising pH, especially in acidic sandy soils.

In recent decades, there has been a growing interest in the recycling of organic materials such as paper mill biosolids (PB) and biochar for use as soil amendments. However, the benefits of co-application of PB and biochar and its effects on soil phosphorus (P) availability remain unknown. An incubation study was conducted on two acidic soils to assess the effect of two PB types (2.5% w/w) co-applied with three rates (0%, 2.5%, and 5% w/w) of pine (Pinus strobus L.) biochar on soil P fractions. An unfertilized control and a mineral NP fertilizer were used as a reference. Soil P fractions were determined by Hedley procedure after 2 and 16 wk of incubation. Material fractionation indicated that the PB containing the highest total P and the lowest Al content had the highest proportion of labile P, whereas most P in the biochar was in a stable form. The incubation study revealed that the P-rich PB increased P availability in both soils to a level comparable to mineral fertilizer at the end of the incubation. The addition of biochar to PB, however, did not affect soil P availability, but the highest rate induced a conversion of P fixed to Al and Fe oxides towards recalcitrant forms, particularly in the sandy loam soil. We conclude that co-applying biochar and PB could be more beneficial than application biochar alone and soils amended with such a mixture would be expected to release part of their P slowly over a longer period of time.

Amending croplands with forest residues may help in restoring soil properties in fields subject to intensive land management. Despite their known benefits when applied separately, co-application of wood biochar with paper mill biosolids (PB) has seen little investigation under field conditions. A study was initiated in Québec, QC, Canada, to determine the effect of a single application of wood biochar with and without PB on the nitrogen (N) and phosphorus (P) availability of two pH-neutral to alkaline loamy soils. Biochar at 0, 10, and 20 Mg dry weight·ha−1 and PB at 30 Mg wet weight·ha−1 were applied before planting of corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] in 2018. Residual effect of this co-application was determined under soybean and corn in the subsequent year. In both years, corn received supplemental N and P from mineral fertilizers according to local agronomic recommendations. Co-applying biochar and PB reduced soil NO3-N availability in the year of application and decreased corn yield by 1.0 Mg·ha−1 compared with biochar or PB applied alone, but these amendments did not affect soybean yields. In the following year, the previous biochar addition increased soybean yield by 0.6 Mg·ha−1 but had little effect on corn. For both years, biochar addition induced a large increase in soil Mehlich-3 P. This study revealed that wood biochar positively impacted P status of these soils but was not a source of N to crops even when co-applied with PB.

Mine tailings are nutrient deficient, contain no organic matter, and have high metal concentrations preventing the long-term establishment of vegetation. The use of organic amendments, including biosolids, can help the revegetation of mine tailings by adding organic matter and nutrients but can increase metals in the receiving soil. There is also uncertainty if biosolids provide a long-term benefit, or if the benefits diminish with time. To test this, a study was conducted on two tailings storage facilities — a sand, and a silt loam — for a copper mine in the southern interior of British Columbia, Canada. In 1998, biosolids were applied at rates between 50 and 250 Mg·ha−1and compared with a control and fertilizer treatment. Plots were sampled in 2000 and 2015 for total and available nutrients and metals. This study showed that 17 yr after a one-time biosolids application at different rates, the tailing storage facilities that received biosolids had higher carbon, nitrogen, phosphorus, and biomass compared with tailings that did not receive biosolids or received conventional fertilizer. Many elements such as carbon (C) did not change from 2000 to 2015 in biosolids-treated plots, indicating a long-term benefit to the tailings. Additionally, biosolids did not result in increased concentrations of metals above the national regulatory limits for agriculture. This study suggests that a one-time biosolids application can provide a long-term benefit to tailings, whereas proper application rates can reduce the risks of metal exceedances.

Biosolids are a by-product of wastewater treatment, and their nutritional composition makes them ideal for fertilizing crops. However, pre-treatments, such as conditioning and/or (vermi)composting, are often required to stabilize the product and remove pathogens. Biosolids, cow manure, and a 50–50% mixture were conditioned for 21 days, composted or vermicomposted with Eisenia fetida (Savigny 1826) for 28 days, and applied to soil cultivated with wheat (Triticum sp. L.), while emissions of nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2) were monitored. Emissions of CH4 were large from the biosolid and N2O from the cow manure during conditioning. Emissions of CH4 remained high during (vermi)composting of the biosolids, while the emissions of N2O from the cow manure dropped. The addition of E. fetida did not affect the emissions of greenhouse gases during (vermi)composting. The emission of N2O was higher when (vermi)composted biosolid was applied to soil cultivated with wheat than when (vermi)composted cow manure was applied. The global warming potential (GWP) of the sum of the emitted greenhouse gases (GHG) during conditioning, (vermi)composting, and when the final product was applied to soil was 3 times larger from the cow manure than from the biosolid, but mixing biosolid with cow manure eliminated that difference. It was concluded that mixing biosolid with cow manure might be a simple way to reduce the GWP of the emitted GHG during storage, (vermi)composting, and when applied to soil.

Land application of organic wastes such as sewage effluent, biosolids, and animal wastes can introduce pharmaceuticals and personal care products (PPCPs) into soils. Food plants grown in soils receiving organic wastes may take up PPCP contaminants and accumulate them in the edible tissues. The purpose of this review is to summarize the latest findings on root uptake of PPCPs and their transfer in soil–plant systems, aiming to identify potential risks associated with organic waste application in crop production systems. The processes and mechanisms of root uptake of PPCPs and their subsequent transfer in plants are intensively discussed in the present review. Soil properties, PPCP physicochemical properties, and plant species are demonstrated as the most important factors influencing the uptake and transfer of PPCPs in soil–plant systems. The metabolism processes and mechanisms of PPCPs in plant tissues are further elucidated with exemplification of commonly used PPCPs. The estimated daily intake is employed to assess the potential risks of consuming PPCP-containing foods based on their accumulation in edible plant tissues. Two innovative treatment techniques are proposed as cost-effective practices to reduce PPCP transfer into plants from organic wastes. Accumulation of PPCPs in edible plant tissues is governed by the combined processes of their root uptake, translocation, and metabolism in plants. This paper reviews the latest research advances in understanding the transfer of PPCPs in soil–plant systems, proposes mitigation practices to minimize PPCP entry into food chains, and identifies research challenges.

Biosolids are a nutrient-rich stable substance obtained during wastewater treatment process. With amplifying population and industrial development, upsurge of biosolid generation is also speculated. Biosolids are endowed with essential plant nutrient (macro- and micro-nutrients) which qualifies them to be used as soil amendment and in turn dwindles the use of chemical fertilizers. The characteristics of biosolid depends on the nature of the treatment process. In this regard, it would be possible to recycle certain nutrients from the agricultural use of biosolids and could be a sustainable solution to the management of this waste. Biosolids may therefore serve as a key tool for farm utilization. It improves the soil health through nutrient supply and promotes the plant growth. Furthermore, they are slow-release fertilizer and hence, restrains from groundwater contamination. This review, in a nutshell, unravels the influence of biosolids on land application, its effect on soil properties, agricultural and horticultural crops, environmental ramification of biosolids in restoring the degraded land and carbon sequestration.

Publisher Copyright: © 2021 The Authors. Published by American Chemical Society The global prevalence of antibiotic resistance genes (ARGs) is of increasing concern as a serious threat to ecological security and human health. Irrigation with sewage and farmland application of manure or biosolids in agricultural practices introduce substantial selective agents such as antibiotics and toxic metals, aggravating the transfer of ARGs from the soil environment to humans via the food chain. To address this issue, a hyperaccumulator (Sedum plumbizincicola) combined with biochar amendment was first used to investigate the mitigation of the prevalence of ARGs in cadmium and oxytetracycline co-contaminated soil by conducting a pot experiment. The addition of biochar affected the distribution of ARGs in soil and plants differently by enhancing their prevalence in the soil but restraining transmission from the soil to S. plumbizincicola. The planting of S. plumbizincicola resulted in an increase in ARGs in the soil environment. A structural equation model illustrated that mobile genetic elements played a dominant role in shaping the profile of ARGs. Taken together, these findings provide a practical understanding for mitigating the prevalence of ARGs in this soil system with complex contamination and can have profound significance for agricultural management in regard to ARG dissemination control.

Zwitterionic, cationic, and anionic per- and polyfluoroalkyl substances (PFAS) are increasingly reported in terrestrial and aquatic environments, but their inputs to agricultural lands are not fully understood. Here, we characterized PFAS in 47 organic waste products (OWP) applied in agricultural fields of France, including historical and recent materials. Overall, 160 PFAS from 42 classes were detected from target screening and homologue-based nontarget screening. Target PFAS were low in agriculture-derived wastes such as pig slurry, poultry manure, or dairy cattle manure (median ∑46PFAS: 0.66 μg/kg dry matter). Higher PFAS levels were reported in urban and industrial wastes, paper mill sludge, sewage sludge, or residual household waste composts (median ∑46PFAS: 220 μg/kg). Historical municipal biosolids and composts (1976–1998) were dominated by perfluorooctanesulfonate (PFOS), N-ethyl perfluorooctanesulfonamido acetic acid (EtFOSAA), and cationic and zwitterionic electrochemical fluorination precursors to PFOS. Contemporaneous urban OWP (2009–2017) were rather dominated by zwitterionic fluorotelomers, which represented on average 55% of ∑160PFAS (max: 97%). The fluorotelomer sulfonamidopropyl betaines (X:2 FTSA-PrB, median: 110 μg/kg, max: 1300 μg/kg) were the emerging class with the highest occurrence and prevalence in contemporary urban OWP. They were also detected as early as 1985. The study informs for the first time that urban sludges and composts can be a significant repository of zwitterionic and cationic PFAS.

Dewatering of anaerobic digested (AD) sludge containing waste-activated sludge (WAS) from enhanced biological phosphorus removal (EBPR) poses numerous challenges including poor dewaterability, struvite scale formation, and recycling of high N and P levels in the sludge liquor to the treatment process. A full-scale water reclamation facility was investigated to mitigate these problems by experimenting with direct dewatering of EBPR WAS, bypassing the AD step. The investigations experimented with various blends of AD primary sludge with undigested thickened WAS to achieve dewatering performance improvements and overall operational cost savings. Direct thickened WAS dewatering has had many positive impacts including enhanced sludge cake solids concentration, reduced chemical use for facility operations, reduced struvite scaling, reduced biogas conditioning media servicing, eliminated need for centrate treatment, recovered capacity of existing unit operations including anaerobic digesters, and eliminated several proposed capital improvement projects that were previously deemed necessary. Although bypassing of WAS to AD reduced total biogas production, the specific gas yield increased to meet all of the facility's biogas demands and minimized excess gas flaring. The overall biosolids production mass increased causing increased transportation costs for disposal and caused notable odors, both of which are being currently investigated. PRACTITIONER POINTS: Direct WAS dewatering bypassing anaerobic digestion yields operational and process benefits in an EBPR water resource recovery facility Dewatered cake solids were increased compared with combined primary and WAS anaerobic digestion and dewatering Nutrient loads in sludge processing returns streams and operational costs are reduced by direct WAS dewatering.

Military activities can contaminate productive land with potentially toxic substances. The most common trace metal contaminant on military bases is lead (Pb). A field experiment was begun in 2016 at Fort Riley, KS, in an area with total soil Pb concentrations ranging from 900 to 1,500 mg kg-1 and near-neutral pH. The main objectives were to test the potential of Miscanthus sp. for phytostabilization of the site and to evaluate the effects of soil amendments on Miscanthus growth, soil-plant Pb transfer, bioaccessibility of soil Pb, and soil health. The experimental design was a randomized complete block, with five treatments and four replications. Treatments were (a) existing vegetation; (b) Miscanthus planted in untilled soil, no amendments; (c) Miscanthus planted in tilled soil; (d) Miscanthus planted in tilled soil amended with inorganic P (triple superphosphate applied at 5:3 Pb:P); and (e) Miscanthus planted in tilled soil amended with organic P (Class B biosolids applied at 45 Mg ha-1 ). Tilling and soil amendments increased dry matter yields only in the establishment year. Total Pb uptake, plant tissue Pb concentration, and soil Pb bioaccessibility were significantly less in the Miscanthus plots amended with biosolids than the Miscanthus plots with no added P across all 3 yr. Enzyme activities, organic carbon, and microbial biomass were also greater in biosolids-treated plots. Results show that planting-time addition of soil amendments to Pb-contaminated soil supported Miscanthus establishment, stabilized and reduced bioaccessibility of soil Pb, reduced concentration and uptake of Pb by Miscanthus, and enhanced soil health parameters.

The disposal of waste biomass generated from biological wastewater treatment plants is a costly process and poses environmental threats to the receiving environment. This study aimed to determine the suitability of algae and waste activated sludge (WAS) produced from a brewery effluent treatment system as a fertiliser in agriculture. The change in soil characteristics and the growth of a crop fertilised with algae or WAS was compared with a conventional inorganic fertiliser. Swiss chard plants (Beta vulgaris) fertilised with anaerobically digested (AD) algae or WAS had a significantly higher mean biweekly yield (5.08 ± 0.73 kg/m2) when compared with the inorganic fertiliser control (3.45 ± 0.89 kg/m2; p < 0.0001). No difference was observed in the soil's physical fertility when algae or WAS were applied to the soil (p > 0.05). The nitrogen applied to the soil from algae and WAS biomass appeared to leach out of the soil less than the nitrogen supplied by inorganic fertilisers. The application of WAS or algae on soil increased the soil's sodium concentration and sodium absorption ratio from 774.80 ± 13.66 mg/kg to 952.17 ± 34.89 mg/kg and 2.91 ± 0.04 to 3.53 ± 0.13, respectively. Regulations on the application of algae or WAS on agricultural soils should be altered to consider the limit values for sodium. HIGHLIGHTS Swiss chard production was similar when fertilised with fertiliser, waste activated sludge or algae.; Anaerobically digested waste activated sludge and algae can replace inorganic fertiliser.; Waste activated sludge and algae increased the soil's sodium absorption ratio.; Soil application rates of sludge should consider sodium limit values.

En las últimas décadas se ha trabajado activamente para reducir el impacto ambiental generado por las actividades antrópicas que constantemente liberan componentes tóxicos al ambiente generando inestabilidad y daños en la salud de las comunidades biológicas. Entre los diferentes contaminantes, los metales pesados revisten importancia en virtud de sus propiedades, que dificultan su degradación o transformación en otros compuestos menos tóxicos. El cromo es uno de los metales de mayor interés a nivel global por su uso en múltiples industrias. Los métodos convencionales que utilizan materiales cromados en sus procesos, no sólo arrojan cantidades considerables de residuos al ambiente, sino que dan poca cuenta de la fracción de Cr6+ presente en determinados ecosistemas. La biorremediación se ha propuesto como una alternativa económicamente viable y ambientalmente sostenible. El propósito del presente trabajo fue evaluar la capacidad de reducción de cromo por bacterias, aisladas de una matriz de biosólidos de la Planta de tratamiento de aguas residuales (PTAR) San Fernando en la ciudad de Medellín-Colombia. Muestras de biosólidos se cultivaron en Agar Nutritivo enriquecido con diferentes concentraciones de Cr6+. Las cepas que presentaron mayor tolerancia al cromo fueron aisladas para realizar ensayos de reducción por triplicado, monitoreando la concentración del metal en el tiempo. Se obtuvieron siete especies bacterianas diferentes dentro de las cuales se destacaron Staphylococcus saprophyticus, Ochrobactrum anthropi y Bacillus cereus por la capacidad de reducir Cr6+ a 96 h con eficiencias de 29.0%, 61.1% y 100%, respectivamente.

Literature review provides extensive studies focused on the life cycle assessment of wastewater treatment plants. However, few studies have a mitigation perspective, especially concerning water–energy–nutrient nexus or resource recovery systems for warm-weather countries. In this context, this paper aims to evaluate 10 wastewater treatment plants, based on an upflow anaerobic sludge blanket followed by a high rate aerobic pond. The recovery of biosolids, energy, and water, thermal and alkaline hydrolysis, CO2 recirculation to supplement carbon, and a membrane system for microalgae harvesting are tested. The paper uses the OpenLCA 1.9 software to evaluate the following categories: global warming potential and global temperature change potential (IPCC 2013); cumulative energy demand (Ecoinvent); acidification, human toxicity, marine and freshwater eutrophication, marine, freshwater and terrestrial ecotoxicity (ReCiPe (H) v.1.13 2008). Input data consist of a background (from Ecoinvent 3.5 and literature) and foreground mix. The work asses the following environmental aspects: energy, chemical materials use, transportation, and emissions. The results indicate that the scenario considering CO2 recirculation combined with thermal hydrolysis, with higher biosolids and energy production, has the lowest environmental impact for all categories. This result was due to materials manufacture and transportation, and comparative inputs added (natural gas energy, water, and fertilizer). Additionally, transportation variation only affects highly the iron chloride supply scenario. Emissions variation impacted directly on both IPCC categories for all scenarios, due to biogas losses accounted on the upflow anaerobic sludge blanket and anaerobic digester, while energy variation did not affect profoundly any of the scenarios.

Abnormally high-odor detection threshold (DT) values were detected for biosolids produced at one of the water resource recovery facilities (WRRFs) of Washington Suburban Sanitary Commission. As an inexpensive countermeasure, aeration of thickened sludge holding tanks (SHTs) was tested as a solution for mitigating the subsequent biosolids odor emission. Experimental results indicated that the extremely low-oxidation reduction potential (ORP) in the SHTs and the fermentation of high-rate-activated sludge were primarily contributors to the odor emission from the dewatered cake. Two rounds of bench-scale experiments on different days confirmed that aerating the sludge in holding tanks reduced peak emission concentrations of sulfurous odorous compounds such as hydrogen sulfide (H2 S), methanethiol (MT), and dimethyl sulfide (DMS) from 203, 110, and 20 mg m-3 g-1 dry to 119, 70, and 14 mg m-3 g-1 dry, respectively. Further preliminary full-scale validation study showed that even a slight ORP improvement from -180 mV to -162 mV reduced the peak H2 S concentration from 87 to 48 mg m-3 g-1 dry and decreased the biosolids DT value from 4266 to 1862. It was concluded that lifting ORP in SHTs through aeration can be used by utilities as a simple means for biosolids odor control. PRACTITIONER POINTS: Anaerobic storage of high-rate active sludge was the main reason for the excessive biosolids odor. Aeration of sludge holding tanks can effectively reduce biosolids odor. A slight oxidation reduction potential improvement substantially reduced biosolids odor.

Pelleted biosolids (PBS) can be used as a low-cost nutrient source alternative to conventional fertilizers for row crop production. A field study was conducted on a Marietta loam at the Plant Scien...

Wastewater treatment and post-treatment drying techniques play a crucial role on the fertilizer value of biosolids. The aim of this study was to investigate: the nitrogen fertilizer value of biosolids from selected biosolid treatment and post treatment dewatering techniques (a) and the effect of drying depth and time on the nitrogen content of biosolid (b). To achieve the first aim, laboratory nitrogen mineralization study was conducted using thermally-hydrolysed-biosolid, activated-biosolid, and anaerobically-digested-biosolids. To achieve the second aim five drying depths were tested (5, 10, 15, 20 and 25 cm). Nitrogen release per tonne biosolid applied was highest for activated (24 kg), and lowest for anaerobically-digested-biosolid (6 kg). Highest total nitrogen was reported for 10 cm drying depth (3.63%) (4 weeks) and lowest for 25 cm (2.64%) (8 weeks). Selection of appropriate biosolid treatment and dewatering technique is key to improve fertilizer value of biosolids.

Combined papermill biosolids (PB) and forest-derived alkaline by-products are known for their direct benefits to agricultural crops, but their residual effects after several years of application have received little attention. A 10 yr field study was initiated on a loamy soil at Yamachiche, QC, to assess the residual effects of PB application after nine consecutive years, either alone or with several liming by-products, on nitrogen (N), phosphorus (P), and metal accumulation in plant and crop yield. The treatments consisted of PB at 0, 30, 60, and 90 Mg wet·ha−1, three liming by-products (calcitic lime, lime mud, and wood ash), each at 3 Mg wet·ha−1 with 30 Mg wet PB·ha−1, and a mineral N fertilizer (MIN). During the residual years, only the MIN treatment was carried out every year according to crop needs. Grain yield and total plant N and P accumulation were evaluated each year, whereas metal accumulation was determined on a 3 yr cycle. The residual effects of PB applications increased crop yields in some years, but the effects were generally lower than with MIN. Plant N recovery in the first three residual years was half of that recorded during years of application (15% vs. 30%), whereas P recovery was at 6%. Residual PB applications had little effect on metal accumulation in grain. Soil liming decreased zinc and cadmium concentrations in grain but increased molybdenum. This study showed that repeated applications of PB and alkaline materials continued to have a positive effect on field crops 3–5 yr after their cessation.

Struvite from nutrient-rich wastewaters has been identified as a potential substitute for commercial mineral fertilisers, with the added benefit of reducing threats to global food security by prolonging phosphate rock reserves. A fertilisation test using grass (Brachiaria brizantha Marandú) and a sand column leaching test was conducted to determine the agronomic effectiveness of struvite precipitates produced from the supernatant of dewatered sewage sludge (centrate) from a municipal Wastewater Treatment Plant (WWTP). The performance of this struvite as a fertiliser was compared with biosolids and commercial fertilisers (Urea and Triple15). The results show that the concentration of heavy metals in struvite was lower than in biosolids and below the limits of Colombia and European fertiliser regulations. Struvite increased the uptake of N and P in grass, resulting in crop yields similar to other treatments tested. Struvite use as an effective slow-release fertiliser is highly dependent on the size of crystal particles, particularly in achieving low P losses, but resulted in high N loss in the sand columns tested; N loses from struvite were higher than in the commercial fertilisers due to the struvite small particle size. Therefore, struvite represents a suitable opportunity to recover and recycle nutrients from municipal sewage sludge, facilitating the effective reuse of P and N in agriculture and uptake by plants. HIGHLIGHTS Heavy metal concentrations of the struvite from the studied centrate of a WWTP were below the threshold limits.; P uptake and apparent P recovery efficiency by the grass were significantly higher in two struvite treatments than in the commercial fertilised tested.; N and P leaching depend on particle size. Smaller crystals can produce greater N uptake by the grass but at the same time more significant N losses by leaching.

Endocrine-disrupting compounds (EDCs) are exogenous compounds that interfere with the normal hormone functions and ultimately lead to health disorders. Parabens, phenols, and phthalates are well-known EDCs, produced globally in large quantities and widely used in a variety of applications. Several studies have monitored these compounds in a variety of environmental matrices, including air, water, sediment, fish, human tissues, soil, indoor dust, and biosolids, etc. In recent years, environmental contamination and human exposure to these chemicals have become a great concern, due to their residue levels exceeding the permissible/acceptable limits. In this review, we focus on the origin of these EDCs, aquatic contamination pathways, distribution, human exposure, health implications, and healthcare costs. Further, this review identifies critical challenges and future research needs in removing or minimizing environmental contamination and exposure to these chemicals to protect living resources.

Wastewater treatment plants (WWTPs) could reintroduce microplastics into environments via biosolid application on land. Yet, the annual emission of microplastics via wastewater biosolids is unclear...

Marshes, and tidal salt marshes in particular, are gaining recognition as critical elements in sustainable shoreline protection (Narayan, Beck, Reguero, et al. 2016; Narayan, Beck, Wilson, et al. 2016; Spalding, Ruo, et al. 2014; Spalding, McIvor, et al. 2014). They contribute to coastal resiliency not only by attenuating wave energy in large storms (Gedan et al. 2011; Moller, Kudella, et al. 2014), but also by maintaining the existence of coastal land (Kirwan et al. 2016), supporting sheries (Boesch & Turner 1984; MacKenzie & Dionne2008), sequestering carbon (Ouyang & Lee 2014), and removing contaminants (Dhir et al. 2009; Windham et al. 2003). These benets directly contribute to the sustainability of the growing populations in coastal regions (Sutton-Grier, Wowk, et al. 2015). With thisrecognition, there are many ongoing projects to preserve existing salt marshes, restore former marshes, and create hybrids of natural and engineered structures (Pontee et al. 2016). These projects require an understanding of the underpinning processes that lead to marsh sustainability. The projects presented in this dissertation are efforts to better understand marsh dynamics. The fist project explores the impact of emergent vegetation on gas flux in marsh surface waters. Wind causes the stems of emergent vegetation to wave back and forth, stirring the water column and facilitating gas exchange. To understand the magnitude of this effect, a gas transfer velocity (k600-value) was measured via laboratory experiments. Measuring this transport pathway contributes to a mechanistic understanding of gas flux and can improve models of climatically important gases. The second project examines wave attenuationacross a salt marsh. Salt marsh vegetation is effective at reducing wave energy. It is important to understand how this attenuation varies. Through field measurements, wave attenuation is explored as a function of hydrodynamic conditions, season, and vegetationtype. The results showed that even fringe marshes, which are common in San Francisco Bay, are effective at reducing wave energy year-round. The last project investigates the viability of using biosolids as an amendment to dredged material in marsh restorations. Biosolids is a reliable and sustainable source of sediment, and more sources of sediment are needed for marsh restoration projects. Both the aboveground and belowground biomass increased when vegetation was grown in soil containing biosolids as compared to only dredged material. Taken together, the three projects discussed here can contribute to improving the success and effciency of marsh restoration and preservation.

The stock of organic carbon contained within a soil represents the balance between inputs and losses. Inputs are defined by the ability of vegetation to capture and retain carbon dioxide, effects that management practices have on the proportion of captured carbon that is added to soil and the application organic amendments. The proportion of organic amendment carbon retained is defined by its rate of mineralisation. In this study, the rate of carbon mineralisation from 85 different potential soil organic amendments (composts, manures, plant residues and biosolids) was quantified under controlled environmental conditions over a 547 day incubation period. The composition of each organic amendment was quantified using nuclear magnetic resonance and mid- and near-infrared spectroscopies. Cumulative mineralisation of organic carbon from the amendments was fitted to a two-pool exponential model. Multivariate chemometric algorithms were derived to allow the size of the fast and slow cycling pools of carbon to be predicted from the acquired spectroscopic data. However, the fast and slow decomposition rate constants could not be predicted suggesting that prediction of the residence time of organic amendment carbon in soil would likely require additional information related to soil type, environmental conditions, and management practices in use at the site of application.

Triclosan (TCS) is a broad-spectrum antimicrobial agent that has been widely used in pharmaceutical and personal care products. TCS enters the environment mainly in effluent and biosolids from wastewater treatment plants, and persists in the aquatic environment and edatope. TCS is potentially harmful to the environment and biohealth because of its properties, being lipophilic, accumulative, toxic, and persistent. Therefore, TCS has become a research hotspot in recent years. The purpose of this review is to summarize the occurrence, toxicity, ecological effects, and removal methods of TCS. TCS has a long half-life, and is found widely in the environment. Toxicity and ecological effects of TCS have been found in recent studies. Moreover, TCS has joint effects with multiple pollutants, and many of its transformation products are also toxic. Methods to remove TCS from the environment include adsorption, advanced oxidation technology, ecological engineering, and applying multiple methods in tandem. Each method is constantly being updated. This paper reviews recent research done on TCS, focusing on its occurrence, toxicity, ecological effects, and removal. Finally, several perspectives for research on this substance are outlined.

Hydrothermal liquefaction (HTL) is a thermochemical process that can convert organic materials in sewage sludge into crude-like oil. Knowledge of the rheology of sewage sludge as a feedstock is important for the design of a HTL Biorefinery as it provides essential information for pumping, pipeline design and heat transfer processes. This study aims at elucidating the rheological behaviour of sewage sludge slurries. Rheological parameters of sludge obtained from different stages in Wastewater Treatment Plants were estimated and used to calculate the pumping power required for slurry transportation in pipelines as part of the front-end engineering design stage for a biorefinery. Sludge slurries were determined to be Non-Newtonian with shear thickening characteristics. Statistically, the Herschel-Bulkley rheological model best fitted the experimental data with a yield stress. The apparent viscosity of municipal sewage sludge slurries measured within a shear rate range from 10 s−1 to 300 s−1 were determined to be between 0.008−0.05 Pa.s for stockpiled biosolids, 0.04−0.11 Pa.s for sludge without polymer dosage and 0.1−0.2 Pa.s for dewatered sludge with polymer. Power requirement for pumping sludge slurries were in the order: Stockpiled biosolid < Sludge without polymer dosage < Sludge with polymer dosage.

Soil fertility has become an interconnected aspect of modern agriculture, incorporating factors such as nutrient availability from soil, and its revision has become necessary for ensuring sustainability. Therefore, to understand the solubility of nutrients from organomineral fertilizers pelleted with biosolids and sugarcane filter cake, and to evaluate the resulting chemical changes in soil from its use, an experiment was performed in a completely randomized design. The experiment was done with four replicates in a 3 × 5 +1 factorial scheme, using three fertilizer sources (mineral fertilizer, organomineral fertilizer pelletized with biosolids, and organomineral fertilizer pelletized with the filter cake); five doses (60%, 80%, 100%, 120%, and 140% of the recommended dose of fertilization for corn); and an additional control treatment (absence of fertilization). The formulation of the organomineral fertilizers was 5-17-10 with 10% total organic carbon. All fertilizer sources were packed in a microfiber cloth positioned 1 cm below the surface of the soil and incubated for 60 days. Subsequent evaluation of chemical attributes: pH H2O (1:2.5); pH SMP (Shoemaker-McLean-Pratt); and the content of exchangeable aluminum, phosphorus, potassium, calcium, magnesium, silica, and organic matter within the soil was done. Organomineral fertilizers pelleted with biosolids or filter cake do not acidify the soil, but they were found to reduce aluminum saturation and promote a slow release of nutrients, which allowed a more balanced base in the soil. This then ensured a better balance of nutrients, with greater cation exchange capacity, base sums, and base saturation. The use of these fertilizers can contribute to stabilizing the pH of the soil with fewer applications of acidity correctives

Per- and polyfluoroalkyl substances (PFAS) are incredibly useful additives, often providing excellent surface tension-lowering properties to a material. Due to the extensive use of PFAS in daily life in developed countries, PFAS invariably collects in municipal wastewater. Without targeted removal of PFAS at wastewater treatment plants, PFAS can move through the treatment process into both the recycled water and biosolids. The presence of PFAS in biosolids poses a potential challenging problem to society for many reasons. A small number of countries have cautiously started, or have at least considered, limiting the concentration of PFAS permitted in biosolids that are to be used for land application. Our review covers the current limits on PFAS concentrations in Australian biosolids, along with the latest developments in international regulations. We found that only Maine, USA, has set upper limits of PFAS for “beneficial use of solid wastes”. Denmark, Germany, The Netherlands, Sweden and Australia have set PFAS limits in soils. No other countries were found to have PFAS limits relating to biosolids or their use; however, this also reflects the lack of industrialisation and centralised wastewater management in many parts of the world.

Two forest soil B-horizons were amended with alkaline-treated biosolids (ATB), powdered agricultural lime, and wood fly ash under controlled conditions to compare initial ion availabilities over a 10-week period. ATB was most effective in supplying available Ca2+but least effective in supplying available Mg2+, for which lime was most effective. Availability of K+and SO42–-S was greatest in fly ash amended soils because of high K and S loading rates and the high electrical conductivity of this amendment. Mineral N (NO3–-N + NH4+-N) availability increased in ATB amended soils, stayed the same in lime amended soils, and decreased in fly ash amended soils. Availability of PO43–-P was low in all soils but slightly enhanced in ATB amended soils. Fluxes of Cu2+, Pb2+, Zn2+, and Mn2+in amended soils generally decreased over time in association with increased soil pH. Fluxes of Cd2+were not affected by any treatment. Results suggest that ATB is equally as effective as or more effective than lime and fly ash at immediately supplying Ca2+, but less effective at supplying Mg2+because of low inputs and cation competition. This suggests that ATB amendments could be an alternative means of quickly adding available Ca2+to Ca-depleted forest soils as long as potential impacts on other nutrient base cations are considered.

Sewage sludge/biosolids are widely used in intensive farming to maintain fertility and enhance crop yields. Therefore, characterization of these matrices is necessary to ensure their safe use, especially regarding the presence of contaminants of emerging concern (CECs), namely pharmaceutical active compounds (PhACs). Little to no studies have ever been conducted in Portugal in this type of matrices, meaning these results may impact the way wastewater sludges are used moving forward. Accelerated solvent extraction (ASE) coupled to the solid-phase extraction (SPE), and high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was optimised for the analysis of 24 PhACs in sewage sludge samples from two Portuguese urban wastewater treatment plants (UWWTP), Beirolas and Faro. The limit of detection (LOD) and quantification (LOQ) for the PhACs ranged between 1.66 ng g−1 and 10.5 ng g−1 and between 5.49 ng g−1 and 34.5 ng g−1 in dry weight, respectively. Sixty-seven sewage sludge samples were analysed, with caffeine being the most prevalent compound, with the highest concentration measured in Beirolas and Faro of 4035 ng g−1 and 129.9 ng g−1, respectively. Carbamazepine, acetaminophen, diclofenac, naproxen, sulfapyridine, and propranolol were also prevalent, with a percentage of detection higher than 80%. The sewage sludges are indeed efficient in retaining PhACs, and the physico-chemical properties of PhACs and the soil must be evaluated when considering the use of sewage sludge as fertilizers in agriculture. Soils' pH is crucial to PhACs adsorption. Regarding target PhACs, only ibuprofen and sulfamethoxazole can potentially be absorbed by plants.

In the framework of circular economy, the need of new feedstock materials for the production of alternative new products is of high priority. Biowastes such as manure, sewage sludge (biosolids, BS) and food-waste are used as raw materials for the production of biochar. The present study aims at characterizing biochars produced from three distinct biowastes (i) manure from cattle waste (manure-derived biochar; MDB), (ii) biosolids (BS) from a conventional Urban Wastewater Treatment Plant (UWTP) (biosolids-derived biochar; BDB), and (iii) spent coffee grounds (SCG)-derived biochar (SCGDB). Samples were slowly pyrolyzed in a small-scale kiln with a capacity of 20–24 kg. The samples were heated under nitrogen atmosphere at approximately 6–7 °C min−1 up to the desired temperature (550 °C) and held for 1.5h. The physicochemical characterization of biochars showed the production of alkaline materials with similarities and variations in their characteristics, which depend to the type of feedstock used. The surface area of the raw materials was considerably low (

Background Eutrophication of the Baltic Sea, and many other water bodies, is partly the result of point-source emissions of nutrients and carbon from wastewater. At the same time, nitrogen and phosphorus planetary boundaries have been breached. There is a need for more efficient resource management, including the recovery and reuse of nutrients and carbon in waste. The aim of this paper is to collate evidence on ecotechnologies intended for use in the wastewater sector globally to facilitate the recovery or reuse of carbon and/or nutrients. Methods Searches were performed on literature published between 2013 and 2017 and in 5 bibliographic databases, 1 search engine, and 38 specialist websites. Database searches were performed in English. Searches in specialist websites were also performed in Finnish, Polish and Swedish. There was no geographical limitation. Screening was conducted at title and abstract level, and on full texts. Apart from bibliographical information, we extracted information on ecotechnology type, intervention, details of the recovery or reuse, the type of wastewater stream to which the ecotechnology is applied, the study location, type and design. Prior to screening and coding, we conducted consistency checks amongst reviewers. We generated a searchable database of coded studies. Findings were synthesised narratively and visualised in a geographical information system (i.e. an evidence atlas). We identified a series of knowledge gaps and clusters that warrant further research. Results The search resulted in 4024 records, out of which 413 articles were retained after the screening process. In addition, 35 pre-screened studies from the specialist website searches were added. Together, these 448 articles contained 474 individual studies of 28 types of ecotechnologies. A combination of ecotechnologies (16.7%), followed by microalgae cultivation (14.1%) were the most frequent ecotechnologies in the evidence base. Ecotechnologies for recovery composed 72.6% of the evidence base. The most common wastewater streams for recovery were mixed wastewater and sludge (73.8%). There was a relative lack of studies on recovery from source-separated wastewater. The most common type of recovery was energy (27.3%), followed by simultaneous recovery of nitrogen and phosphorus (22.1%). Reuse of recovered substances was described in 22.8% of the studies. The most common type of reuse was of nitrogen and phosphorus (57.4%), followed by joint reuse of organic carbon, nitrogen and phosphorus (35.2%). Reuse ecotechnologies were mostly focused on the use of wastewater for irrigation or reuse of biosolids, and not on the nutrients that had been extracted through e.g. precipitation of struvite. In 22 studies both recovery and reuse were described. In total, 60 different study countries were reported in the evidence base, and the most common study location was China. Conclusions We found substantial evidence for the recovery and reuse of nutrients and carbon from wastewater sources. The relative abundance of studies where substances are recovered compared to studies where they are reused, suggests a knowledge gap on reuse of recovered nutrients and carbon. The majority of studies on reuse were on irrigation with treated wastewater or reuse of biosolids, and not on reuse of extracted nutrients such as struvite.

The goal of this article is the evaluation of the compost quality from Kraft mill organic matter by germination Raphanus sativus and Lepidium sativum. The evaluation of compost was measured in term...

The increase in the cultivation of sugarcane for energy purposes has raised awareness regarding the possibilities of mitigating the associated environmental impacts. This study applies the Life Cycle Assessment (LCA) methodology to quantify and compare the environmental impacts associated with the use of commercial chemical fertilization and industrial biosolids in the production of sugarcane. LCA was developed with the SimaPro® software, utilizing the Ecoinvent and Agri-footprint databases. The environmental impact assessment methods employed were the IPCC 2013 GWP 100y and Eco-indicator 99. An experiment was devised at an experimental farm located in Northeast Brazil, considering 1 ha cultivated with sugarcane. For commercial chemical fertilization, local management practices were followed. The biosolid was applied in the exact dosage recommended by Brazilian regulation, “biosolid 1x”. This amount was then multiplied by two, four, and eight, totalling four scenarios. The environmental loads generated in the cultivation of sugarcane decreased with the application of “biosolid 1x”. All biosolid dosages tested reached higher production values than commercial chemical fertilization. The application of biosolid as a fertilizer contributed to addressing the issue of its correct disposal and is a promising alternative for the development of more sustainable and productive energy systems.

El suelo proporciona servicios ecosistémicos fundamentales como la regulación del ciclo del nitrógeno, el cual, es dirigido por la microbiota que éste alberga y su estabilidad depende ante perturbaciones bióticas o abióticas, como la contaminación por metales y metaloides. Altas concentraciones de níquel (Ni) y zinc (Zn) en suelos agrícolas están relacionadas con la aplicación de prácticas agrícolas convencionales, composta, biosólidos, así como riego con agua contaminada proveniente de la industria minera y termoeléctrica, principalmente. Con el objetivo de conocer los efectos de dicha perturbación abiótica, se realizó un estudio a nivel microcosmos con suelo agrícola proveniente de la Costa de Hermosillo, Sonora, México, perturbado con compuestos M-salfen de Ni(II) y Zn(II), para evaluar su efecto basado en el funcionamiento del ciclo del nitrógeno en el sistema a lo largo del tiempo. Análisis espectrofotométricos de la reserva de nitrógeno inorgánico, absorción atómica y pH revelaron la recuperación de la funcionalidad del ciclo del nitrógeno en 240 días posteriores a las perturbaciones con M-salfen aplicadas, sugiriendo la utilización de NiSB15 como promotor para el incremento de la concentración de nitrato a los 60 días, en conjunción con NiSA15 para aumentar la concentración de amonio en suelos agrícolas contaminados con metales pesados.

This paper presents the results of a comprehensive geotechnical laboratory testing for the assessment and design of a proposed biosolid monofill facility at the As-Samra Waste Water Treatment Plant (WWTP) in Jordan. Previous landfill operations for biosolid materials typically involved co-disposal or lagooning of the dewatered biosolid slurry. However, it is proposed that the solar-dried As-Samra WWTP biosolid material will be placed in a new monofill facility at the site. This approach is suited to the As-Samra desert climate, since the material’s water content can be readily reduced to between 60 and 100% in evaporation lagoons. New insights were gained on the strength and compressibility of the non-inundated and saturated compacted biosolid materials, including their (a) very low normalised undrained strength ratio and effective angle of shearing resistance values for the saturated normally consolidated states of 0·14 and 15°, respectively; (b) very high strain rate dependency of strength; and (c) extremely low permeability coefficient values on the order of 10−12 m/s for compaction at approximately 100% water content. The paper concludes with recommendations on the appropriate water content range for compaction of the material in the proposed monofill and the selection of design strength values for geotechnical stability analysis.

Advancements in the field of residuals, sludge, and biosolids have been made in 2019. This review outlines the major contributions of researchers that have been published in peer-reviewed journals and conference proceedings throughout 2019 and includes brief summaries from over 125 articles. The review is organized in sections including life cycle and risk assessments; characteristics, quality, and measurement including micropollutants, nanoparticles, pathogens, and metals; sludge treatment technologies including dewatering, digestion, composting, and wetlands; disposal and reuse including adsorbents, land application and agricultural uses, nutrient recovery, and innovative uses; odor and air emissions; and energy issues.

The issue of sustainable management of biosolids (excess sludge) from wastewater treatment is an important issue in the entire developed world. Residual sludge disposal costs and environmental impact may be significant, and reducing such costs, as well as the energy consumption for dewatering and drying, is a key issue for safe and sustainable sludge disposal, considering the recent ban of some disposal options, such as landfilling, in many European countries. An alternative to thermal technologies is solar drying (not to be confused with bio-drying, very close to the concept of composting). Solar greenhouse drying technology is characterized by reduced land requirements compared with traditional outdoor drying beds, as well as by low-energy requirements compared with other thermal drying methods. Process operation is cost-efficient, with close to no maintenance, and observed specific evaporation rates up to threefold higher than conventional drying beds. Many applications of this technology exist in Poland, Germany and Austria: more than 10,000 t of wet sludge per year is treated in this way in Germany alone and almost as many (9000 t/year) in Poland. This paper examines current biosolids treatment technologies applicable to small wastewater treatment plants (2000–9999 population equivalents served) and opportunities for possible solids reuse in Poland in view of sustainable circular economy schemes. In particular, a purely solar-driven greenhouse facility for sewage sludge drying was investigated under different conditions (season, temperature, environmental humidity) and possible improvements for its efficiency evaluated. Sludge processed by solar drying could have different final disposal pathways, according to season, in accordance with the prescriptions of the new National Waste Management Plan of Poland.

There is increasing concern over the presence of per- and polyfluoroalkyl substances (PFAS) in biosolids, while sales in commercially available biosolid-based products used as soil amendments are also increasing. Here, the occurrence of 17 perfluoroalkyl acids (PFAAs) present in 13 commercially available biosolid-based products, six organic composts (manure, mushroom, peat, and untreated wood), and one food and yard waste compost were studied. The PFAA concentration ranges observed are as follows: biosolid-based products (9.0-199 μg/kg)food and yard waste (18.5 μg/kg)other organic products (0.1-1.1 μg/kg). Analysis of 2014, 2016, and 2018 bags produced from one product line showed a temporal decrease in the total PFAAs (181, 101, and 74 μg/kg, respectively). The total oxidizable precursor (TOP) assay revealed the presence of PFAA precursors in the biosolid-based products at much higher levels, when the soluble carbon was removed by the ENVI-Carb clean-up prior to the TOP assay. Time-of-flight mass spectrometry confirmed the presence of three sulfonamides, two fluorotelomer sulfonates, and several polyfluoroalkyl phosphate diesters. Pore-water concentrations of water-saturated products were primarily of short-chain PFAAs and increased with increasing PFAA concentrations in the products. A strong positive log-linear correlation between organic carbon (OC)-normalized PFAA partition coefficients and the number of CF

Synthetic fertilizers make up a significant fraction of the energy required to grow switchgrass (Panicum virgatum L.) for ethanol production. A field study compared biosolids and synthetic fertilizers on biomass yield, ethanol production, and nitrous oxide (N2 O) emissions of switchgrass to determine if using an alternative source of nutrient would lower the energy density of the fuel. Minimal N2 O emissions were observed the first year of the study (0.99 ± 1.5 g N2 O ha-1 d-1 for biosolids), with no difference between treatments. Biosolids were added in excess of agronomic rates, and gas samples were collected immediately after irrigation for the subsequent years to examine maximum N2 O emissions. Mean Year 2 emissions increased for fertilizers to 1.8 ± 8 g N2 O ha-1 d-1 (n = 131) and to 3.73 ± 10.2 g N2 O ha-1 d-1 (n = 130) for biosolids-amended soils. Emissions in Year 3 were similar to Year 2. Yield was similar and ranged from 3.7 ± 5 to 11 ± 1.1 and from 5.0 ± 0.2 to 13.4 ± 1.7 Mg ha-1 for biosolids and fertilizer, respectively. The potential ethanol yield was 365 ± 28 L Mg-1 and 374 ± 34 L Mg-1 for the biosolids- and fertilizer-grown grass, respectively. Greenhouse gas emissions associated with fertilizer production were considered for N, P, and K and totaled 1,653 kg carbon dioxide equivalent (CO2 e) ha-1 . The equivalent credits for substitution of biosolids (18 Mg ha-1 ) were -2,492 kg CO2 e ha-1 . Nitrous oxide emissions were calculated based on 1% of total N applied for agronomic applications and were 8,600 and 3,500 g N2 O ha-1 for the biosolids and fertilizer treatments, respectively. Total carbon costs associated with fertilization were 2,700 kg CO2 e ha-1 for fertilizer and 60 kg CO2 e ha-1 for biosolids. Using measured N2 O data would have resulted in lower emissions for both treatments.

Treated wastewater produces sewage sludge as a by-product that may have beneficial implications on agricultural practices. The effects of sludge amendments on growth, morphological and biochemical characteristics of the agro-industrial Tomato cultivar Rio Grande were observed. A pot culture experiment was carried out during 4 months (16 February 2019 to 18 June 2019), at an experimental green house in the locality of Salah Soufi, Guelma, north-eastern Algeria. There were significant differences between soil and sewage sludge samples. Total nitrogen (20.58 mg/kg) was more available in sewage sludge than in soil (N = 2.09 ± 0.3 mg/kg). In contrast, sludge contained less phosphorus and organic matter than soil. The observation of the morphological characteristics of the plants showed significant variations between the treatments. The germination rates for treated soils decreased significantly to reach 50%, compared to the control. Growth patterns (dry and fresh weight of leaves and roots) changed significantly (P

A better understanding of crop and soil response to biosolids is necessary for optimizing their use as soil amendments. The present study examined the influence of sewage sludge application on N accumulation, partitioning, translocation, and N use in sunflower and on soil properties compared with mineral fertilizers. Treatments included the application of sewage sludge (9, 18, and 36 Mg dry weight ha−1 year−1), an inorganic fertilizer (138 kg N plus 55 kg P2O5 ha−1 year−1), and a non-amended control. Sewage sludge increased early crop growth rate and N uptake at levels similar to or even greater than those obtained with the inorganic fertilizer. Nitrogen translocation was correlated with nitrogen translocation efficiency (r = 0.66*); both parameters appeared to be associated with source and sink attributes. Nitrogen use efficiency and nitrogen uptake efficiency were decreased with increasing rates of sewage sludge following a quadratic response curve. The estimated nitrogen use efficiency of sewage sludge-added N was greater than that of the inorganic fertilizer when sewage sludge was applied at agronomically realistic rates (

With the rampant boom in faecal sludge (FS) collection and management in line with Indian government’s agenda, quite a few urban local bodies (ULBs) in Telangana such as Greater Warangal Municipal Corporation (GWMC) initiated into establishing faecal sludge treatment plant (FSTP) in collaboration with experienced private technology partners such as Banka BioLoo Limited. FSTPs were so designed with minimal mechanical components to regularize it as a popular choice for rural and sub-urban. The GeoTube based technology makes use of an organic flocculant to maximize the floc formation and thereby the water recovery. Post-flocculation the sludge is fed into a semi permeable polypropylene trap (GeoTube®) with a pore size of 0.3 mm. The method of dewatering the septage with the aid of GeoTube was so designed to ensure greater than 98% efficacy. Ultimately, the above effluent gets polished with a series of tertiary units such as pressure sand filter, activated carbon filter, UV disinfection, etc. The permeate meets the inland water disposal standards and is used to maintain the green belt in and around the plant. The trapped biosolids are self-composted for more than two months inside the filled tubes. Further, the debagged material is analyzed to ensure compliance with physico-chemical, metallic, and pathogenic limits. Afterward, the final materials pulverized, packed, and distributed amid the local farmers to be used as a soil conditioner. The FSTP has been successfully running for about two years now and has to date treated more than 2 million liters of septage of which recycled almost 1500 kL of water and 35 tons of biosolids.

A study was conducted to test the suitability of a range of organic and inorganic residuals mixed with municipal biosolids to create a soil amendment effective for a broad range of end uses. Biosolids suitable for unrestricted use were sourced from San Francisco, CA. Residuals including urban wood and yard waste, nut shells, biochar, and sawdust were sourced from nearby producers. Existing biosolids based soil products, peat, and a yard-food compost were used as controls. Experimental mixtures were tested for a range of soil properties, appearance, odor, germination, and growth response. Several mixtures performed as well as or better than the yard-food compost, and several performed comparably to the biosolids soil controls. Yard waste fines blended with biosolids in a 50:50 ratio by volume or yard waste fines blended with biosolids and 20% sand at 40:40:20 were highly effective across all measured indices. Mixed yard and recycled lumber fines blended with biosolids at these same ratios performed similarly well. Blends with a high percentage of char performed poorly in germination and growth response, likely as a result of elevated electrical conductivity. Certain blends such as gypsum and redwood shavings failed to mix well with biosolids to create a uniform looking material and were less visually appealing. In general, blends that met established quality control parameters for compost performed well on the measured indices. These results suggest that blending Class A biosolids with organic and inorganic feedstocks to meet quality criteria developed for compost will create marketable soil products.

Treated sewage sludges (SSs) or biosolids are rich in organic carbon, nutrients, and, unfortunately, chemical contaminants. Accumulation of chemicals in SS is influenced by the mass of chemical produced and released into wastewater, resistance to (bio)degradation during treatment, and the chemicals' propensity to sorb to particulates. Hence, accumulation of chemicals in SS is indicative of their persistent and bioaccumulative behavior: the two characteristics that are predominantly used for chemical prioritization. Thus, it is possible for risk assessors to use existing SS survey data to identify, rank, and prioritize persistent and bioaccumulative chemicals present in the human society. In this review, we highlight unique papers that used this concept to help prioritizing chemical contaminants in SS and the environment. We additionally showcase a simple decision flowchart and scoring algorithm for prioritizing chemicals whose presence in SS warrants further investigation.