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Biosolids have benefits for soil and crop production and contribute to sustainable development. The use of biosolids in agriculture holds great potential for enhancing the economic development of rural communities. This research aims to analyze the mediating role of attitudes between knowledge and the intention to use biosolids as fertilizer. During the examination process 635 questionnaires were obtained, and statistical analysis was performed using Smart-PLS. The results of the study indicate that attitudes play a mediating role between knowledge and the intention to use biosolids in agriculture. In conclusion, it is emphasized in the need for positive attitudes towards the use of biosolids among agricultural managers, directors, technicians, and farmers. These results benefit the Dominican Republic's Ministry of Agriculture, agricultural professionals, and farmers. The Ministry can shape policies and offer education on biosolid use. Agricultural leaders should consider attitudes alongside knowledge. Farmers should stay informed and adopt biosolid practices for better crop productivity and soil health. [ABSTRACT FROM AUTHOR]

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A double-pronged approach to pollution management is proposed by sustainably managing solid wastes and converting them to activated carbons that are then utilized for water treatment. In this study, gas-to-liquids (GTL) derived biosolids, carboard and their mixed samples are used to produce the activated carbons. In a laboratory batch study, a Box-Behnken experimental design was used with four factors and three levels to optimize the removal of single component strontium and barium, and the binary system of pollutants from an aqueous solution. The design incorporated response surface modeling (RSM) techniques with a total of 29 different experimental data points collected and analyzed in this study. The study was conducted considering four parameters: the initial pH of the solution (ranging from 4.0 to 8.0), temperature (ranging from 20 to 40 ℃), the percentage of cardboard (fixed at 0 %, 50 %, and 100 %), and the amount of adsorbent (between 0.05 and 0.5 g). These factors were assigned three levels, represented as −1, 0, and 1. A second-order polynomial regression equation was then developed to estimate the responses. The statistical significance of the independent variables and their interactions was assessed using analysis of variance (ANOVA) with a 95 % confidence level (α = 0.05). The results revealed that only temperature and dosage show significant effects on the responses and that optimum values of the selected parameters were obtained by solving the prediction equations, which were validated with less than 4 % error %. In an attempt to optimize the factors, a pH of 5.5, temperature of 40 ℃ and dose of 0.3 g is found for all three samples. Validation results for optimization also proved that varying the percentage cardboard showed little difference in the percentage removal of all the pollutants. The results from this study can be directly applied for any such systems trying to optimize these parameters and the prediction equations can be utilized effectively. [Display omitted] [ABSTRACT FROM AUTHOR]

Keywords: Costs; Wastes; Sludge; Water Systems; Wastewater Treatment; Streams; Liability; Coagulation; Lime; Softening; Biosolids EN Costs Wastes Sludge Water Systems Wastewater Treatment Streams Liability Coagulation Lime Softening Biosolids 6 7 2 11/03/23 20231101 NES 231101 The US Environmental Protection Agency (EPA) is preparing to advance several actions that could have costly implications for drinking water and wastewater treatment facilities with waste residual streams containing per- and polyfluoroalkyl substances (PFAS). The listing of PFAS as hazardous constituents is a first step toward listing wastes containing PFAS as hazardous wastes, which triggers more controlled waste management requirements (e.g., documentation and reporting, transportation, disposal practices). While EPA has not yet initiated a rulemaking to list PFAS-containing wastes as RCRA hazardous wastes, the listing of PFAS as hazardous constituents is a first step that puts the process in motion. [Extracted from the article]

Environmental contamination caused by emerging pollutants (EPs) and their associated ecological risk have received limited attention in India. Thus, this study aims to address this gap by investigating the occurrence and removal of antibiotic resistant bacteria (ARB), antibiotic resistance genes (ARGs) and pharmaceutical and personal care products (PPCPs) in two sewage treatment plants (STPs) in New Delhi. The study also assessed the ecological risk associated with PPCPs in aquatic environments. Among the targeted ARB and ARGs, erythromycin resistant bacteria and erm B gene, respectively were the most ubiquitous pollutants in the influent of both STPs. In the final effluent, there was a reduction ranging from 0.8 log to 2.8 log units for most ARB, while removal of the majority of ARGs was less than 1 log unit. The secondary treatment demonstrated better removal of total ARG concentrations compared to the tertiary treatment methods employed in both STPs. Regarding PPCPs, metformin was quantified in both influent and effluent samples at a concentration exceeding 19,000 ng/L, indicating its persistence in wastewater. High concentrations of ARB, ARGs, and PPCPs were observed in undigested biosolids, while low to moderate removal of these pollutants was observed after anaerobic digestion. To assess the ecological risk, a risk quotient (RQ) assessment was conducted. The results revealed that compounds such as erythromycin, terbinafine, 17-α ethinylestradiol (EE2), 17-β estradiol (E2), diclofenac, triclosan, carbamazepine, and mefenamic acid exhibited high risks in the effluent. Additionally, EE2 and E2 showed higher risk levels in the digested biosolids, indicating potential risks to the aquatic ecosystem. [Display omitted] • Secondary treatment outperformed tertiary treatment in antibiotic resistant bacteria and resistance genes removal. • Metformin persisted in influent and effluent of both sewage treatment plants. • Digested sludge contains substantial levels of micropollutants and antibiotic resistance (ARB and ARGs). • Endocrine disruptive compounds (E2 and EE2) showed the highest ecological risk. [ABSTRACT FROM AUTHOR]

Biosolids can be effectively recycled and applied as soil amendments for agricultural crops because they contain several important micro and macronutrients including nitrogen, phosphorus, potassium, manganese. In the current study, we evaluated the effectiveness of seven biosoilds on different growth parameters of wheat crop. The biosolids used were lime stabilized, composted, liquid mesophilic anaerobically digested (liquid MAD), thermally dried mesophilic anaerobically digested (thermally dried MAD), thermally hydrolyzed mesophilic anaerobically digested (thermally hydrolysed MAD), dewatered mesophilic anaerobically digested (dewatered MAD) and thermally dried raw biosolids. We also analysed biosolids for their nutrient contents before application. The results revealed that different types of biosolids differed in nitrogen and phosphorous contents with highest contents observed in dewatered (5.70% nitrogen, 2.32% phosphorous) and liquid biosolids (2.35% phosphorous). The plant height, plant diameter and dry weight yield of wheat was increased with the increase in concentrations of biosolids. Liquid MAD resulted in maximum plant height of 120.35 ± 3.23, 133.2 ± 3.67 and 147.25 ± 3.11 at 3.33, 6.66 and 9.99 tons/ha concentration. The highest plant diameter was recorded (1.05–1.45 cm) where mineral nitrogen was applied. The study will be helpful in replacing the synthetic fertilizer with biosolids to fulfil the nutritional requirements of agricultural crops. [ABSTRACT FROM AUTHOR]

The article offers water distribution related news briefs. U.S. Geological Survey (USGS) and independent scientists evaluating the use of sensor-mounted unmanned aircraft systems (UAS). Arizona State University (ASU) in Tempe providing grant from National Aeronautics and Space Administration (NASA).

Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Despite the ban on new manufacture and commercial use of PCBs, municipal sewer systems continue to serve as ongoing secondary sources for contamination in receiving water bodies. Ongoing PCB sources have made it difficult to achieve desired recovery after implementation of sediment cleanup efforts. We report on a 16-month surveillance to determine the inputs, fate, and export of PCBs within a municipal waste collection/treatment system by strategic sampling of the freely-dissolved and biosolids-associated PCBs. The total PCBs entering the treatment plant was found to be 170 g/day of which 100 g/day exited the plant associated with the biosolids and 5.2 g/day was discharged in the form of freely-dissolved PCBs in the effluent. A net loss of 68 g/day was calculated for the plant, attributable to volatilization and biodegradation. Freely dissolved PCBs in the treated effluent was an order of magnitude higher than the water quality criteria for the protection of human health through fish consumption and found to be a major contributor to the dissolved concentration in the receiving river. Predicted bioaccumulation in fish from dissolved PCBs in the effluent exceeded the threshold for human consumption. The biosolids, currently land-applied as fertilizer, contained an average PCB concentration of 760 μg/kg. The sludge produced in this treatment plant is processed in large anaerobic digesters and changes to the homolog distribution point to some microbial dechlorination. Application of biosolids to clean agricultural soil resulted in a 6-fold increase in PCB levels in the earthworm E. fetida which could be eliminated by the amendment of 1% by weight of activated carbon. Graphical abstract Image 1 Highlights • Fate of dissolved and particle-associated PCBs in an urban wastewater treatment plant. • Passive sampling used to accurately measure freely dissolved PCBs in wastewater. • 58% of the 170 g/d PCBs entering the plant is retained in the biosolids. • Biosolids application to soil results in 6-fold increase in PCB uptake in earthworms. • PCBs in the final effluent exceeds human health risk threshold for fish consumption. PCBs exiting a large City wastewater treatment plant through biosolids and effluent water pose significant risk of exposure to the ecosystem. [ABSTRACT FROM AUTHOR]

Abstract Carbamazepine (CBZ) is an antiepileptic drug that is frequently detected in wastewater treatment plants, soil and plants after irrigation with treated wastewater or application of biosolids. However, little information is available on the fate and uptake of CBZ in edible vegetables. In this study, radioautographic visualization of the 14C distribution revealed that 14C-CBZ can be taken up by all three ready-to-eat vegetables. Furthermore, a mass-balance study was conducted to evaluate the dynamic processes of the uptake and translocation of CBZ by 14C labeling. 14C-CBZ was gradually taken up with the growth of vegetables, with maximum uptake ratios of 2.19 ± 0.15, 2.86 ± 0.24 and 0.25 ± 0.05% of applied 14C in celery, carrot and pak choi, respectively. The bioconcentration factors (BCFs) based on 14C measurements ranged from 7.6 to 26.1 for celery, 3.6–12.9 for carrot, and 4.4–44 for pak choi. 14C-CBZ was easily translocated from the roots to the leaves and/or stems. The amendment of biosolids had a significant inhibitory effect on the uptake and translocation of 14C-CBZ from soil. Graphical abstract Image 1 Highlights • 14C Labeling was used to understand plant uptake and translocation of carbamazepine from soil. • 14C-Carbamazepine can be taken up by all three ready-to-eat vegetables. • 14C-Carbamazepine was easily translocated from roots to the leaves and/or stems. • Biosolids inhibited the uptake and translocation of 14C-carbamazepine from soil. 14C-CBZ can be taken up by vegetables and easily translocated from the roots to the leaves and/or stems, and biosolids inhibited the uptake and translocation of 14C-CBZ from soil. [ABSTRACT FROM AUTHOR]

Triclosan (TCS) is a broad-spectrum antimicrobial used in a variety of consumer products. While it was recently banned from hand soaps in the US, it is still a key ingredient in a top-selling toothpaste. TCS is a hydrophobic micropollutant that is recalcitrant under anaerobic digestion thereby resulting in high TCS concentrations in biosolids. The objective of this study was to determine the impact of TCS on the antibiotic resistome and potential cross-protection in lab-scale anaerobic digesters using shotgun metagenomics. It was hypothesized that metagenomics would reveal selection for antibiotic resistance genes (ARGs) not previously found in pure culture studies or mixed-culture studies using targeted qPCR. In this study, four different levels of TCS were continuously fed to triplicate lab-scale anaerobic digesters to assess the effect of TCS levels on the antibiotic resistance gene profiles (resistome). Blasting metagenomic reads against antibiotic/metal resistance gene database (BacMet) revealed that ARG diversity and abundance changed along the TCS concentration gradient. While loss of bacterial diversity and digester function were observed in the digester treated with the highest TCS concentration, FabV, which is a known TCS resistance gene, increased in this extremely high TCS environment. The abundance of several other known ARG or metal resistance genes (MRGs), including corA and arsB, also increased as the concentrations of TCS increased. Analysis of other functional genes using SEED database revealed the increase of potentially key genes for resistance including different types of transporters and transposons. These results indicate that antimicrobials can alter the abundance of multiple resistance genes in anaerobic digesters even when function (i.e. methane production) is maintained. This study also suggests that enriched ARGs could be released into environments with biosolids land application. [ABSTRACT FROM AUTHOR]

Sludge processing and biosolids management represent significant ongoing activities for the wastewater treatment industry. Historically, a substantial inventory of sludge processing technologies and operating practices have been developed within regions to manage sludges and produce products that meet disposition requirements. However, access to system-wide information on sludge handling practices that would be of interest to a variety of wastewater industry stakeholders is often not available. As an example, there is little system-wide information available on the types of sludge processing technologies employed and the quantity and quality of biosolids produced at wastewater treatment plants in Ontario. In the present study quantitative data on sludge handling over the period 2014–2016 was gathered for Wastewater treatment plants (WWTPs) with a hydraulic capacity greater than 1000 m 3 /day. The types of technologies employed were sorted by the design hydraulic capacity (DHC) of the WWTPs. Data on key biosolids properties (i.e. solids content, pathogen indicators, metals, nitrogen and phosphate) were sorted by WWTP DHC and related regulations. Drivers that are expected to impact biosolids handling practices in Ontario in the future are proposed and discussed in context of the current practices. [ABSTRACT FROM AUTHOR]

Sewage management exhibits all characteristics of a ‘wicked’ problem: it is framed as a technical problem even though it is surrounded by scientific uncertainties, and the framing hides both value-frameworks and the unequal distribution of risks and benefits. In this study, we analyze how uncertainties and the limits of scientific knowledge are approached and communicated in two jurisdictions that presently are in the process of revising their regulatory frameworks pertaining to land application of the residuals remaining after sewage treatment: Sweden, which is governed by the EU Directive 86/278/EEG, and the Canadian province of British Columbia, which draws heavily on the US EPA503 Rule. We find that the two jurisdictions take very different approaches to uncertainty and ignorance: The BC framing rests on the presumption that no evidence of harm can be taken as evidence that the practice is safe and draws on a persuasive narrative to that end. In contrast, the Swedish narrative rests on the presumption that absence of evidence cannot be taken as evidence of absence and that it therefore is better to hark on the safe side, when it is technically possible. The BC framing is indicative of a classic risk assessment approach and public acceptance is addressed as a knowledge deficit problem. The pursuasive tone and lack of transparency appears to negatively impact residents' trust in regulatory agencies. The Swedish framework takes a more precautionary approach, combining risk assessment with hazard determination and uses a deliberative and transparent approach, seemingly producing more socially ‘robust’ knowledge. Even though Sweden pays considerable attention to the challenges involved in making assessments based on limited data, the limits of science-based knowledge is not touched upon. In fact, Sweden and BC signal a similar view on humanities' ability to create reliable knowldge: given sufficient time, it will eveutally be possible to close the knowledge gaps and develop reliable (technical) solutions. We argue that treating the problem as if it is a technical challenge at its heart hides social aspects and forward that the value-judgements that underlie hazard determinantions and risk assessments must be transparently identified and communicated, including the assessment of uncertainty and the limits of science, to avoid increased polarization and thus hardened conflicts. [ABSTRACT FROM AUTHOR]

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Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Phosphorus (P) scarcity and eutrophication have triggered the development of new approaches for phosphorus recovery. This study investigated the impact of calcium-doped biochar, produced from biosolids via microwave pyrolysis at 700 °C for 20 min, on phosphorus recovery. The phosphorus removal isotherms, removal kinetics and the impact of initial pH of phosphorus solution on phosphorus recovery were studied. The phosphorus recovery was proportional to the calcium content in biochar, leading predominantly to the production of brushite. Precipitation was the main mechanism of phosphorus removal by calcium-doped biochar. Phosphorus removal capacity of biochar reached equilibrium after 8 h of contact time and was described by a pseudo-second-order kinetic model. The Langmuir isotherm model fitted the experimental data well with a maximum adsorption capacity of 147 mg-P/g for biochar BC20 (20 wt% Ca(OH) 2 ). The results of phosphorus removal from a real wastewater demonstrated that using Ca-doped biochar for phosphorus removal from contaminated streams is a promising alternative for phosphorus recovery as well as for biosolids management. Heavy metal leaching from Ca-doped biochar was much lower than from undoped biochar, and decreased as the amount of calcium in biochar increased. [ABSTRACT FROM AUTHOR]

Suppression of plant growth is a common problem in post-mining reclaimed areas, as coarse texture of soils may increase nitrate leaching. Assessing feasibility of using solid waste (precipitated solid matter) produced by water and sewage treatment processes in field conditions is very important in mine soil reclamation. Our work investigated the possibility of plant growth in a degraded site covered with sewage-derived sludge material. A test area (21 m × 18 m) was established on a mine soil heap. Experimental plant species included Camelina sativa, Helianthus annuus, Festuca rubra , Miscanthus giganteus, Amaranthus cruentus, Brassica napus, Melilotus albus , Beta vulgaris, and Zea mays. ANOVA showed sufficient water content and acceptable physical properties of the soil in each year and layer in a multi-year period, indicating that these species were suitable for phytoremediation purposes. Results of trace elements assays indicated low degree of contamination caused by Carbocrash waste material and low potential ecological risk for all plant species. Detrended correspondence analysis revealed that total porosity and capillary porosity were the most important variables for the biosolids among all water content related properties. Overall, crop plants were found useful on heavily degraded land and the soil benefited from their presence. An addition of Carbocrash substrate to mine soil improved the initial stage of soil reclamation and accelerated plant growth. The use of this substrate in phytoremediation helped to balance the content of nutrients, promoted plant growth, and increased plant tolerance to salinity. Sewage sludge-amended biosolids may be applied directly to agricultural soil, not only in experimental conditions. [ABSTRACT FROM AUTHOR]

Concentration of 16 polycyclic aromatic hydrocarbons (PAHs), 7 polychlorinated biphenyls (PCBs), and 11 organochlorine pesticides (OCPs) in sewage sludge from 40 wastewater treatment plants (WWTPs) was investigated. Relationship between pollutant sludge contents, main WWTP parameters and type of sludge stabilisation was carefully evaluated. Average load of PAHs, PCBs, and OCPs in different sludges from Czech Republic was 3096, 95.7 and 76.1 μg/kg dry weight, respectively. There were moderate/strong correlations among the individual tested pollutants in sludge (r = 0.40–0.76). Relationship between total pollutant contents in sludge, common WWTP parameters and sludge stabilisation was not evident. Only individual pollutants such anthracene and PCB 52 correlated significantly (P < 0.05) with biochemical oxygen demand (r = −0.35) and chemical oxygen demand removal efficiencies (r = −0.35), suggesting recalcitrance to degradation during wastewater treatment. When sorted according to the design capacity, a linear correlation between WWTP size and pollutant contents in sludge was evident with growing WWTP capacity. Our study indicated that WWTPs with anaerobic digestion are prone to accumulate a statistically higher content of PAHs and PCBs (P < 0.05) in digested sludges compared to aerobically digested ones. The influence of anaerobic digestion temperature of treated sludge on tested pollutants was not evident. [Display omitted] • OCPs, PCBs and PAHs in sludge from WWTPs were 76, 96, and 3096 μg/kg dw. • Moderate/strong correlations among the tested pollutants in sludge were observed. • Anthracene and PCB 52 correlated with biological/chemical oxygen demand. • Linear correlation between WWTP size and pollutant contents in sludge was evident. • Anaerobically digestion is prone to accumulate higher PAHs and PCBs in sludges. [ABSTRACT FROM AUTHOR]

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used globally to treat and prevent illness. Biosolids change physico-chemical characteristics of soil and can affect the mobility of NSAIDs. A field-based lysimeter study evaluated the effect of three rates (0, 7, and 28 Mg ha−1) of alkaline treated biosolids (ATB) on the leaching potential of naproxen (NPX), ibuprofen (IBF), and ketoprofen (KTF) over 34 days in a sandy loam textured soil. Although all three NSAIDs in the lysimeter cells vertically migrated to deeper soil depths after spiking, the sum of all NPX, IBF, and KTF detected in the leachate samples from all treatments were only 0.03%, 0.02%, and 0.04% of the initial spiking mass to the surface soil, respectively. A mass balance analysis indicated a low accumulation of these compounds in the soil at the end of the study (Day 34) from all treatments with only 4.8%, 0.5%, and 0.7% of initial spiked NPX, IBF, and KTF, respectively. Application of ATB significantly increased soil pH and organic matter (OM) content of the soils but did not impact retention of the compounds in the soil profile. Overall, all three NSAIDs in the present study presented low mobility in the loamy sand textured agricultural soil. [Display omitted] • Biodegradation was the main mechanism of NSAIDs dissipation in the lysimeter cells. • Soil amended with biosolids did not impact the NSAIDs retention in the soil profile. • Naproxen, ibuprofen, and ketoprofen as parent compounds showed low mobility in the soil. • The low NSAIDs mass measured in leachate indicated a low risk to the environment. [ABSTRACT FROM AUTHOR]

This study aims to identify and quantify different classes of emerging contaminants (ECs), such as pharmaceutical and personal care products (PPCPs), per-and polyfluoroalkyl substances (PFAS), heavy metals (HMs), polycyclic musks (PMs) in biosolids from different sewage treatment plants (STPs) from regional councils across Northern Queensland, Australia. Biosolids samples were named BS1 to BS7 for each council. The results revealed significant variations in the concentrations of different ECs in biosolids which could be explained in some instances by the characteristics of the upstream sewage network. For instance, BS4-biosolids from a small agricultural shire (largely sugarcane) showed the highest concentration of zinc and copper, which were 2430 and 1050 mg/kg, respectively. Among PPCPs, the concentration of ciprofloxacin was found to be the highest in BS3 and BS5, two large regional council areas which are a mix of domestic and industrial (predominantly domestic) biosolids of 1010 and 1590 ng/g, respectively. In addition, the quantity of sertraline was consistently high in all biosolids except from BS7, one of the smaller regional councils, which is indicative of the domestic catchments attached. PFAS compounds were detected in all biosolids samples except in BS6, one of the small (agricultural and tourist) catchments. Two PFAS compounds emerged as the most common pollutants that were perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). The largest industrial catchment biosolids, BS2 showed the highest concentration of PFOS at 253 ng/g, while the smallest regional council, BS7 showed the maximum concentration of 7.90 ng/g of PFOA. Overall, this study concludes that certain ECs such as HMs, antibiotics, PFOS and PFOA in biosolids may pose high environmental risks. [Display omitted] • All biosolids showed high concentrations of zinc and copper. • PFOS and PFOA were the most common PFAS in biosolids. • Sertraline and ciprofloxacin were dominant PPCPs in all biosolids. • HMs, PFOS and PFHxS, and certain PPCPs showed the significant environmental risks. [ABSTRACT FROM AUTHOR]

Biosolids, biogas and hydrogen sulfide (H 2 S) are byproducts of wastewater plants constantly increasing with growing population. Traditional disposal of biosolids by landfilling, biogas flaring and H 2 S treatment is not integrated. This treatment approach leads to substantial greenhouse gas emissions, up to 54% of total waste industry emissions. It also represents high operating costs for wastewater plants. Only biosolids handling represents between 45% and 65% of wastewater treatment plants operating expenses. The feasibility of obtaining porous media from biosolids for hydrogen sulfide treatment using biogas energy was studied. Literature regarding wastewater byproducts integrated treatment is scarce, and the required data to evaluate the feasibility of byproducts integration is site specific, and is not yet available for treatment plants in Abu Dhabi. Biosolids samples and biogas composition data were obtained from a municipal wastewater treatment plant in Abu Dhabi. Biosolids chemical and physical properties to assess the potential for H 2 S treatment were measured. Literature was reviewed to select biosolids pyrolysis conditions to obtain high porous-surface-areas chars. Experimental pyrolysis was conducted on a Differential Scanning Calorimeter (DSC) measuring the thermal process energy consumption. Biogas energy was estimated from thermodynamic analysis and compared with the biosolids pyrolysis process energy consumption. It was found that biosolids chars surface area (108m 2 /g) is comparable with commercial activated carbons for H 2 S treatment and have an estimate of 11% CaCO 3 which can potentially react with H 2 S. Energy consumption of the biosolids pyrolysis process is only 4% of the available biogas energy in the plant. [ABSTRACT FROM AUTHOR]

The reuse of treated municipal sewage (‘biosolids’) on land is an effective method to divert waste away from landfill and to use an alternative, low cost method of fertilisation. While legislation has mainly focused on the control of nutrient and metal application rates to land, other potentially harmful emerging contaminants (ECs) may be present in biosolids. Up to 80% of municipal sewage sludge is reused in agriculture in Ireland, which is currently the highest rate of reuse in Europe. However, unlike other countries, no study has been conducted on the presence of ECs across a range of wastewater treatment plants (WWTPs) in this country. This study evaluated the concentrations of two ECs in sewage sludge, the antimicrobials triclosan (TCS) and triclocarban (TCC), and their presence in surface runoff following land application in controlled rainfall simulation studies. In 16 WWTPs, concentrations of TCS and TCC were 0.61 and 0.08 µg g −1 , which is at the lower end of concentrations measured in other countries. The concentrations in runoff post land application were also mainly below the limits of detection (90 ng L −1 for TCS, 6 ng L −1 for TCC), indicating that runoff is not a significant pathway of entry into the environment. [ABSTRACT FROM AUTHOR]

Nitrogen, phosphorus and organic matter are valuable resources in sewage sludge. Life cycle assessment (LCA) can be useful for comparing the potential environmental risks of sludge management strategies to their potential environmental benefits. With growing interest in resource recovery from sludge, there is an increasing need to properly account for the benefits that can be achieved, and to handle the multi-functionality issues that then arise in LCAs. So far, both of these aspects have often been handled in a generic and seemingly arbitrary way. The study identified and explored several alternative approaches to handle the multi-functionality in the LCA of a sludge handling system that generates both biogas and a sludge that is used on arable land; either through avoiding allocation by substituting for avoided products or services (e.g. fertilisers and natural gas), or by allocating the impact from the studied system between its functions based on economic terms. The choice of approach strongly influenced the overall LCA-result for the studied system, in particular for some of the studied impact categories. Although an attempt was made to apply economic allocation in this article, it can be concluded that no coherent basis for applying allocation was identified. Substitution was more easily applied, however, the results were highly dependent on the product assumed to be replaced by biogas and the modelling of avoided mineral fertiliser use. The previously neglected benefits related to organic matter provided by the sludge to arable land were potentially as important as the benefits of the nitrogen and phosphorus, although the quantification of such effects will need further refinement, and are only relevant for certain soil conditions. [ABSTRACT FROM AUTHOR]

The disposal of biosolids poses a major environmental and economic problem. Agricultural use is generally regarded as the best means of disposal. However, its impact on soil ecosystems remains uncertain. Biosolids can improve soil properties by supplying nutrients and increasing organic matter content but there is also a potentially detrimental effect arising from the introduction of heavy metals into soils. To assess the balance between these competing effects on soil health, we investigated soil bacterial and fungal diversity and community structure at a site that has been dedicated to the disposal of sewage sludge for over 100 years. Terminal restriction fragment length polymorphism (T-RFLP) was used to characterize the soil microbial communities. The most important contaminants at the site were Ni, Cu, Zn, Cd, and Pb. Concentrations were highly correlated and Zn concentration was adopted as a good indicator of the overall (historical) biosolids loading. A biosolids loading, equivalent to 700-1000 mg kg-1 Zn appeared to be optimal for maximum bacterial and fungal diversity. This markedly exceeds the maximum soil Zn concentration of 300 mg kg-1permitted under the current UK Sludge (use in agriculture) Regulations. Redundancy analysis (RDA) suggested that the soil microbial communities had been altered in response to the accumulation of trace metals, especially Zn, Cd, and Cu. We believe this is the first time the trade-off between positive and negative effects of long term (>100 years) biosolids disposal on soil microorganisms have been observed in the field situation. [ABSTRACT FROM AUTHOR]

In Ireland, the land application of biosolids is the preferred option of disposing of municipal sewage waste. Biosolids provide nutrients in the form of nitrogen, phosphorus, potassium and increases organic matter. It is also an economic way for a country to dispose of its municipal waste. However, biosolids may potentially contain a wide range of pathogens, and following rainfall events, may be transported in surface runoff and pose a potential risk to human health. Thus, a quantitative risk assessment model was developed to estimate potential pathogens in surface water and the environmental fate of the pathogens following dilution, residence time in a stream, die-off rate, drinking water treatment and human exposure. Surface runoff water quality data was provided by project partners. Three types of biosolids, anaerobically digested (AD), lime stabilised (LS), and thermally dried (TD)) were applied on micro plots. Rainfall was simulated at three time intervals (24, 48 and 360 h) following land application. It was assumed that this water entered a nearby stream and was directly abstracted for drinking water. Consumption data for drinking water and body weight was obtained from an Irish study and assigned distributions. Two dose response models for probability of illness were considered for total and faecal coliform exposure incorporating two different exposure scenarios (healthy populations and immuno-compromised populations). The simulated annual risk of illness for healthy populations was below the US EPA and World Health Organisation tolerable level of risk (10-4 and 10-6, respectively). However, immuno-compromised populations may still be at risk as levels were greater than the tolerable level of risk for that subpopulation. The sensitivity analysis highlighted the importance of residence time in a stream on the bacterial die-off rate. [ABSTRACT FROM AUTHOR]

While numerous studies have demonstrated the efficiency of secondary wastewater treatment (WWT) in high rate algae ponds (HRAPs), little consideration has been given to how the algal unit should be best integrated within a full treatment system complying with typical nutrient discharge standards. Using the case study of a 2000 person equivalent (P.E.), we first demonstrate that algal treatment is most efficiently used for combined carbon and nutrient removal because an HRAP designed for compliant N (or P) removal de facto provides free and environmentally-benign carbon removal. The large O 2 excess capacity for aerobic carbon removal also suggests primary suspended solid removal is unlikely needed, although grit removal remains necessary. We then demonstrate combining algal cultivation with anaerobic digestion is not economic at small scale because it offers marginal energy savings (e.g. 10.7€ P.E. − 1 yr − 1 ) while incurring significant costs for digestate transport offsite (e.g. 32.5€ P.E. − 1 y − 1 at a distance of 50 km). Subsequent sensitivity analyses confirmed that while the potential of algae-to-biogas via WWT is limited (e.g. total cost of 38.2€ P.E. − 1 y − 1 in our base case), integrating the use of HRAPs with solar drying has the potential to provide a more economical and energy-efficient WWT alternative for nutrient removal and recovery (24.4€ P.E. − 1 y − 1 ). [ABSTRACT FROM AUTHOR]

Polybrominated diphenyl ethers (PBDEs) may enter the environment because of accumulation in biosolids followed by application to agricultural lands. No published dissipation studies are available for PBDEs in agricultural soils after biosolids application. Therefore, we conducted a 3-year study to examine the fate of PBDEs in a small-scale 0.24-ha continuously cropped field after a single biosolids application at 72.3 wet tons/ha and determined dissipation half-lives for BDE-47+BDE-99 and BDE-209. In addition, we conducted a large-scale survey of soils from 26 mostly pasture fields at 10 farms with detailed information on timing and rate of biosolids applications. In the small-scale experiment, maximum soil PBDE concentrations of 43.7 ± 42.7 μg kg −1 d.w. for BDE-209 and 6.05 ± 7.15 μg kg −1 d.w. for BDE-47+BDE-99 were reached 1 year after application. We hypothesized that PBDEs were slowly released from the biosolids matrix into the soil over the first year. After 3 years, median BDE-47+BDE-99 concentrations were approximately equal to preapplication levels, whereas median BDE-209 concentrations remained ∼129% above preapplication levels. The estimated residence time from the small-scale experiment was 342 d for BDE-47+BDE-99 and 861 d for BDE-209. In the large-scale study, a subset of fields that received a single biosolids application was used to generate another estimate of residence time: 704 d for BDE-47+BDE-99 and 1440 d for BDE-209. These longer residence time estimates were used in three different first-order decay dissipation scenarios (continuous, limited, and no dissipation) to predict PBDE concentration in fields with single and multiple biosolids applications. Results indicate that dissipation occurs primarily in the first 2 years after application, but residues remaining in the soil after this period are likely to be much more tightly bound and less available for degradation. [ABSTRACT FROM AUTHOR]

This study investigated the prevalence and abundance of halogenated flame retardants (HFRs) in sludge samples from 5 sewage treatment plants in Guangzhou, China. Detection of 18 polybrominated diphenyl ethers (PBDEs), 9 alternative HFRs including Dechlorane Plus (DP), brominated alkylbenzenes, and polybrominated biphenyls, and 2 related degradation products was conducted. Decabromodiphenyl ether (BDE 209) and decabromodiphenyl ethane (DBDPE) were the dominant HFRs, with concentrations ranging from 200 to 2150 ng/g and 680–27,400 ng/g, respectively. The DBDPE detected was the highest level reported so far, exceeding those previously reported by 10–100 times. PBDEs were surpassed as the dominant HFRs in sewage sludge, with mean DBDPE/BDE 209 ratio exceeding 2 in all samples. The review of earlier surveys reveals that DBDPE level was surging while BDE 209 was declining. Annual emissions of BDE 209, DP, and DBDPE were estimated to be 227.9, 10.5, and 979.3 kg/yr, respectively. Although ecological risks assessment suggested low risks for the examined sludge, the key environmental properties and transformation pathways of alternative HFRs remain largely unknown. These findings prompt for further investigations on alternative HFR and sustainable management practices for HFR-laden biosolids. The HFR emission pattern revealed in this study is likely representative of other similarly industrialized regions in the post-PBDE era. [ABSTRACT FROM AUTHOR]

A microwave-assisted extraction method for the determination of 15 alkyl, aryl, and halogenated phenols in sewage sludge and biosolids samples was developed and optimized. The effects of solvent, temperature, time, moisture content, acid, and number of extractions on the recovery of phenols were evaluated. Results indicated that extraction solvent had the greatest impact on the recovery of all phenols while pH had the largest effect on recovery of hexachlorophene and pentachlorophenol. Wet sludge samples were extracted with acetone-hexane mixture in the presence of glacial acetic acid. The extract was evaporated, acetylated by acetic anhydride and cleaned up by silica gel. For dry sludge samples, an optional procedure for the simultaneous extraction and acetylation of phenols was also proposed. Triclosan (TCS) and the alkyl and aryl phenols in sludge extracts were analyzed by gas chromatography-mass spectrometry (GC-MS) in electron-impact mode while polyhalogenated phenols were analyzed by GC-MS in negative ion chemical ionization mode. Method detection limits were ca. 200 ng/g for nonylphenol, <25 ng/g for TCS and other alkyl and aryl phenols, and <5 ng/g for other halogenated phenols. This method has been applied to the determination of phenolic compounds in over 150 sludge and biosolids samples since 2009. [ABSTRACT FROM AUTHOR]

The uptake and accumulation of metals in plants is a potential pathway for the transfer of environmental contaminants in the food chain, and poses potential health and environmental risks. In light of increased population growth and urbanisation, the safe disposal of sewage sludge, which can contain significant levels of toxic contaminants, remains an environmental challenge globally. The aims of this experiment were to apply municipal sludge, having undergone treatment by thermal drying, anaerobic digestion, and lime stabilisation, to permanent grassland in order to assess the bioaccumulation of metals (B, Al, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Nb, Mo, Sb, Ba, W, Pb, Fe, Cd) by perennial ryegrass over a period of up to 18 weeks after application. The legislation currently prohibits use of grassland for fodder or grazing for at least three weeks after application of treated sewage sludge (biosolids). Five treatments were used: thermally dried (TD), anaerobically digested (AD) and lime stabilised (LS) sludge all from one wastewater treatment plant (WWTP), AD sludge from another WWTP, and a study control (grassland only, without application of biosolids). In general, there was no significant difference in metal content of the ryegrass between micro-plots that received treated municipal sludge and the control over the study duration. The metal content of the ryegrass was below the levels at which phytotoxicity occurs and below the maximum levels specified for animal feeds. [ABSTRACT FROM AUTHOR]

Waste management planning is a complex task involving a variety factors and professional skills. In order to avoid oversimplification leading to the risk of adopting inappropriate solution the relevant decision problems should be tackled with: (a) a comprehensive decision model (including technical, environmental, economic, social, etc. factors) and (b) a suitable decision supporting tool. In this work as far as (a) is concerned we propose a model based on more than 30 parameters for the evaluation of sewage sludge management strategies. As to (b) we implemented this model by employing both a worksheet (“ home made ” option) and a DSS commercially available (“ buy ” option). As a case study, we considered the selection of the sewage sludge management strategy in a 500,000 inhabitants area comparing the following alternatives: Agricultural use, Incineration, Wet Oxidation and recovery in Cement Kiln. The assessment of the four alternatives led to the following preference order: Agricultural use ≫ Incineration > Cement Kiln ≅ Wet Oxidation. Finally, a discussion on the make-or-buy dilemma and on pros and cons of decision support methods is reported. As a result, a paradigm shift defined make-and-buy approach is proposed. [ABSTRACT FROM AUTHOR]

Biosolids are extensively used in agriculture as fertilizers while offering a practical solution for waste disposal. Many pharmaceutical and personal care products (PPCPs), such as triclosan and triclocarban, are enriched in biosolids. Biosolid amendment changes soil physicochemical properties, which may in turn alter the persistence of PPCPs and hence the risk for secondary contamination such as plant uptake. To delineate the effect of biosolids on PPCPs persistence, triclosan and triclocarban were used as model compounds in this study and their sorption ( K d ) and persistence ( t 1/2 ) were determined in different soils before and after biosolid amendment. Biosolids consistently increased sorption of triclosan and triclocarban in soil. The K d of triclosan increased by 3.9–21 times following amendment of a sandy loam soil with biosolids at 2–10%. The persistence of both compounds was prolonged, with t 1/2 of triclosan increasing from 10 d in the unamended soil to 63 d after biosolid amendment at 10%. The relationship between t 1/2 and K d was further examined through a meta-analysis using data from this study and all relevant published studies. A significant linear relationship between t 1/2 and K d was observed for triclosan ( r 2 = 0.69, p < 0.01) and triclocarban ( r 2 = 0.38, p < 0.05) in biosolid-amended soils. On the average, when biosolid amendment increased by 1%, t 1/2 of triclosan was prolonged by 7.5 d, while t 1/2 of triclocarban was extended by 4.7 d. Therefore, biosolid amendment greatly enhances persistence of triclosan and triclocarban, likely due to enhanced sorption or decreased chemical bioavailability. This finding highlights the importance to consider the effect of biosolids when evaluating the environmental risks of these and other biosolid-borne PPCPs. [ABSTRACT FROM AUTHOR]

The study was conducted in two stages, at laboratory and bench scales, concerning ozone sludge treatment. Operating conditions were experimentally discussed. Both physicalchemical and microbiological characterizations of the sludge generated from Advanced Primary Treatment - APT (coagulation-flocculation-sedimentation) were carried out, before and after ozone treatment. Additionally, the effect of sludge ozonation on the pathogen inactivation, solubilization, mineralization, stabilization and reduction was evaluated. The results indicated that, under the experimental conditions studied at lab scale, ozone has a significant effect on the treated sludge. However, the ozone effect on reduction of individual parameters did not show significant differences among the treatments. Taking into account an economic criterion, an applied ozone dose of 2.6 g.L-1 would be recommended. Values of turbidity, color and absorbance at 254 nm were reduced to 72, 79 and 70%, respectively. Ozonation did not caused change in pH values. The maximum percentage of the resulting solubilization was 72% expressed as COD and 54% as total dissolved solids. The sludge stabilization was achieved with total volatile solids reduction between 58 and 67%. After ozonation, the VSS/TSS ratio decreased from 0.73 to less than 0.26, indicating mineralization of the sludge. Unstirred sludge volume index (SVI) dropped significantly from 55.03 to 13.34 ml.g-1 at 2.6 g.L-1, but it decreased very slightly as ozone dose increased. Moreover, the heavy metals concentration in the sludge did not exceed the limit values of land application reported by international standards. As for disinfection requirements, the results indicated that the sludge treated with ozone can be applied in agriculture. At lab scale, all of the applied ozone doses fulfilled satisfactorily the criteria for disinfection of Class B biosolids, but no dose meets for Class A. However, doses above 2.4 g.L-1 meet the standard for Class A biosolids at bench scale. The results demonstrated that it can be possible to achieve, in an economically feasible manner, the reduction of the volume and the pollution with ozonation of the sludge generated during the APT of a municipal wastewater. An integrated treatment with ozone of sludge, for reuse in agriculture, can be proposed. [ABSTRACT FROM AUTHOR]

Land application of biosolids or compost constitutes an important route of soil contamination by emerging contaminants such as acetaminophen and sulfamethoxazole. Using 14 C labeling, we evaluated the influence of biosolids and compost on individual fate processes of acetaminophen and sulfamethoxazole in soil. The amendment of biosolids or compost consistently inhibited the mineralization of both compounds but simultaneously enhanced the dissipation of their extractable residues or parent form. Immediately after treatment, the majority of 14 C-residue became non-extractable, reaching 80.3–92.3% of the applied amount at the end of 84-d incubation. Addition of biosolids or compost appreciably accelerated the formation of bound residue, likely due to the fact that the organic material provided additional sites for binding interactions or introduced exogenous microorganisms facilitating chemical transformations. This effect of biosolids or compost should be considered in risk assessment of these and other emerging contaminants. [ABSTRACT FROM AUTHOR]

Increasing commercial use of nanosilver has focussed attention on the fate of silver (Ag) in the wastewater release pathway. This paper reports the speciation and lability of Ag in archived, stockpiled, and contemporary biosolids from the UK, USA and Australia, and indicates that biosolids Ag concentrations have decreased significantly over recent decades. XANES revealed the importance of reduced-sulfur binding environments for Ag speciation in materials ranging from freshly produced sludge to biosolids weathered under ambient environmental conditions for more than 50 years. Isotopic dilution with 110m Ag showed that Ag was predominantly non-labile in both fresh and aged biosolids (13.7% mean lability), with E-values ranging from 0.3 to 60 mg/kg and 5 mM CaNO 3 extractable Ag from 1.2 to 609 μg/kg (0.002–3.4% of the total Ag). This study indicates that at the time of soil application, biosolids Ag will be predominantly Ag-sulfides and characterised by low isotopic lability. [ABSTRACT FROM AUTHOR]

Agricultural use of sludge is a beneficial alternative for sludge handling and recycling which may improve soil fertility through providing organic matter and nutrients. This study focuses on sludge application scheduling for suitable arable lands. Ankara (Turkey) was the study site. A screening procedure and buffer zone application were conducted to eliminate the arable lands not suitable for sludge application. ArcGIS was used for spatial analysis. Then a transport cost-based optimization model was employed to determine the lands that would be receiving sludge in a management period of 2013 to 2022. The spatial analysis by ArcGIS indicated that 75% of the total non-irrigated arable lands in Ankara were not appropriate for sludge application. Optimization results showed that only 17% of the suitable lands could receive sludge application for the conditions considered in this study. Average costs for sludge transportation in the management period were $84,855/year, $77,299/year, and $62,349/year for truck capacities of 10, 16 and 24 t, respectively. Total sludge transportation costs decreased for higher truck capacities. Sensitivity analysis indicated that transportation costs and the area of suitable lands receiving sludge were sensitive to sludge application dosage, application frequency, travel distance, and unit fuel cost escalation. [ABSTRACT FROM AUTHOR]

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Manufactured nanoparticles (NPs) present in consumer products could enter soils through re-use of biosolids. Among these NPs are those based on silver (Ag), which are found sulphidised (e.g. silver sulphide, Ag2S) in biosolids. Herein, our aim was to examine the release of retained Ag(0) and Ag2S NPs in soils and biosolids as facilitated by environmentally and agriculturally relevant ligands. Under natural soil conditions, exemplified by potassium nitrate and humic acid experiments, release of Ag retained in soil was limited. The highest total Ag release was facilitated by ligands that simulated root exudates (citrate) or fertilisers (thiosulphate). Released Ag was predominantly present in the colloidal phase (>3 kDa–< 0.45 μm); intact NPs only identified in Ag2S-NP extracts. For biosolids containing nanoparticulate-Ag-S, release was also enhanced by thiosulphate, though mostly as colloidal-Ag–not intact NPs. These results suggest that exposure to NPs as a result of its release from soils or biosolids will be low. [ABSTRACT FROM AUTHOR]

The measurement of dielectric properties of materials is critical to understanding the electromagnetic field distribution in the materials. Reliable knowledge of the dielectric constant is also important when designing a microwave pyrolysis unit for effective pyrolysis of materials of interest. The dielectric probe technique was used to evaluate the dielectric properties of biosolids. Biosolid samples were collected from various sources and the dielectric properties were measured across the microwave frequency range of 1.0 GHz to 10.0 GHz. The dielectric constant of the materials varied in the range from 80 to 2 and depended mainly on the origin of the sample, the electrical conductivity and the moisture content of the material. A mathematical model was developed to accurately predict the values of complex permittivity. This model was verified using the measured data. [ABSTRACT FROM AUTHOR]