Wastewater Treatment Plant Effluent Research Articles

Abundance and seasonal variation of microplastics in the effluents of a wastewater treatment plant: A case study in Greece

Microplastics (MPs) have been detected in numerous ecosystems worldwide. To better understand their distribution and establish a foundation for risk assessment protocols, detailed information on MP concentrations and polymer compositions is essential. This study assessed the presence and chemical composition of MPs, ranging from 5 mm to 125 µm, in the effluents of a Greek wastewater treatment plant (WWTP) over a one-year period to understand the temporal variation in MP input into the receiving water fidentification and mass data were obtained through pyrolysis coupled with gas chromatography/mass spectrometry (Py-GC/MS) analysis. The study found that fibers (50–78 %) were the predominant form of MPs compared to particles, with the most common size range being 125–200 μm for fibers and 200–2000 μm for particles. Py-GC/MS analysis indicated a clear dominance of polyolefins among the polymers analyzed, with MP mass concentrations ranging from 4.5 to 69.29 μg/L. Increased concentrations of MP items and mass were observed following rainfall events (due to elevated discharge and altered hydraulic parameters) and during windy conditions. This underscores the need for improved assessment of background parameters in future MP monitoring strategies. By providing data on MP input in WWTP effluents over a one-year period, this study enhances our understanding of seasonal MP dynamics and can serve as a crucial reference for future measurements.

Ecosystem risk-based prioritization of micropollutants in wastewater treatment plant effluents across China

Identifying priority pollutants in wastewater treatment plant (WWTP) effluents is crucial for optimizing monitoring efforts, improving regulations, and developing targeted mitigation strategies. Despite the presence of numerous trace organic pollutants in WWTP effluents, a comprehensive prioritization scheme is lacking, hindering effective control. This study screened 216 micropollutants, including pharmaceuticals, pesticides, and industrial chemicals, which had been detected in effluents from 46 WWTPs across China. A multi-criteria prioritization method was developed, considering exposure potential based on median concentrations and detection frequencies, as well as hazard potential determined by persistence, bioaccumulation, in vitro toxicity, and in vivo toxicity. Pollutants with low exposure or hazard potential were filtered out, and a priority index was calculated to rank the remaining 59 substances. The top 15 priority pollutants included regulated persistent organic pollutants like perfluorooctanoic acid and their alternatives such as perfluorobutane sulfonate, pesticide transformation products, and emerging contaminants such as bisphenol A, which are not currently regulated in WWTP effluents. This study provides a systematic approach to identify priority pollutants and generates a guiding framework for monitoring, regulation, and control of both well-recognized and overlooked contaminants in WWTP effluents.

Towards carbon neutrality and circular economy: an innovative combination of enhanced biogas production and nutrient recovery from sludge dewatering liquor at a municipal wastewater treatment plant in Germany.

An innovative circular economy (CE) system was implemented at the wastewater treatment plant (WWTP) in Brunswick. The performance of the CE system was evaluated for 4 years: the thermal pressure hydrolysis enhanced the methane production by 18% and increased the digestate dewaterability by 14%. Refractory COD formed in thermal hydrolysis and increased the COD concentration in the WWTP effluent by 4 mg L-1 while still complying with the legal threshold. Struvite production reached high phosphorus recovery rates of >80% with a Mg:P molar ratio ≥0.8. Nitrogen was successfully recovered as ammonium sulfate with high recovery rates of 85-97%. The chemical analyses of secondary fertilizers showed a low pollutant content, posing low risks to soil and groundwater ecosystems. The total carbon footprint of the WWTP decreased due to enhanced biogas production, the recovery of renewable fertilizers and a further reduction of nitrous oxide emissions. Using green energy will be crucial to reach carbon neutrality for the entire WWTP.

A new chemometrically optimised HPLC method for the simultaneous determination of imatinib mesylate and capecitabine, the active medicinal components

ABSTRACT Anticancer drugs such as imatinib mesylate (IMP) and capecitabine (CAP) and their metabolites enter the water cycle through wastewater treatment plant effluents or directly into the water cycle due to their limited biodegradability in typical wastewater treatment plants. However, their long-term effects on water resources are unknown due to their toxicity. The hazards concerned with chronic exposure to these substances raise concerns about their impact on organisms, environmental safety and biodiversity conservation. Therefore, in this study, a chemometrically optimised HPLC method was developed for the simultaneous determination of trace amounts of cytotoxic agents IMP and CAP used in cancer treatment in environmental water, synthetic urine samples and drug samples. Using the Box-Behnken design, optimum conditions discovered using the traditional method were optimised. The effect of each element was evaluated in the design by four factors based on HPLC determination. For the examined levels, mobile phase 1, mobile phase 2 ratio, flow rate, and column temperature parameters for the HPLC method were determined. Using regression analysis on the experimental results, the factors influencing resolution were identified. To achieve the reliability of the results, the Analysis of Variance (ANOVA) test was used. The ANOVA test was employed to verify the consistency of the data. With the information gathered, a model was developed. HPLC was used to examine the target chemicals. A good linearity (R2 > 0.99) was established for the IMP and CAP in the concentration ranges of 1.18–23.59 µg mL−1 and 0.76–15.09 µg mL−1, respectively, under optimum circumstances. The recoveries for spiked samples at three concentration levels ranged from 98.31 to 101.11. The created method has been applied to synthetic urine samples, regional environmental water samples, and pharmaceutical samples with success.

Sexual hormones monitoring in surface waters and wastewaters from Northern Italy by thin film microextraction coupled with HPLC-MS/MS.

The occurrence of sex steroid hormones, viz. oestrogens and progestins, in aquatic ecosystems is of global concern due to their role as endocrine disrupting chemicals, even at low concentration (μg L-1 or less). Thus, it is essential to monitor these organic pollutants to get a realistic picture of their presence and to control their contamination levels in environmental water bodies. In this respect, we have explored the use of self-prepared polymeric films as novel sorptive phase for the microextraction of 17β-estradiol, 17α-ethinylestradiol, estrone, progesterone, medroxyprogesterone acetate and hydroxyprogesterone. The thin film microextraction procedure has been developed, evaluating different film compositions, sample volumes and elution conditions to recover the sorbed analytes. The overall method provides good reproducibility (RSD < 12%) and recoveries higher than 60%. The final method has been applied to environmental monitoring in surface waters (river and lake samples) and urban wastewater treatment plant effluents and influents from Northern Italy, to get a contamination snapshot of this highly urbanized area.

Variable contribution of wastewater treatment plant effluents to downstream nitrous oxide concentrations and emissions

Abstract. Nitrous oxide (N2O), a potent greenhouse gas and ozone-destroying agent, is produced during nitrogen transformations in both natural and human-constructed environments. Wastewater treatment plants (WWTPs) produce and emit N2O into the atmosphere during the nitrogen removal process. However, the impact of WWTPs on N2O emissions in downstream aquatic systems remains poorly constrained. By measuring N2O concentrations at a monthly resolution over a year in the Potomac River estuary, a tributary of the Chesapeake Bay in the eastern United States, we found a strong seasonal variation in N2O concentrations and fluxes: N2O concentrations were larger in fall and winter, but the flux was larger in summer and fall. Observations at multiple stations across the Potomac River estuary revealed hotspots of N2O emissions downstream of WWTPs. N2O concentrations were higher at stations downstream of WWTPs compared to other stations (median: 21.2 nM vs. 16.2 nM) despite the similar concentration of dissolved inorganic nitrogen, suggesting the direct discharge of N2O from WWTPs into the aquatic system or a higher N2O production yield in waters influenced by WWTPs. Meta-analysis of N2O measurements associated with WWTPs globally revealed variable influence of WWTPs on downstream N2O concentrations and emissions. Since wastewater production has increased substantially with the growing population and is projected to continue to rise, accurately accounting for N2O emissions downstream of WWTPs is important for constraining and predicting future global N2O emissions. Efficient N2O removal, in addition to dissolved nitrogen removal, should be an essential part of water quality control in WWTPs.

Artificial neural network modeling for the prediction, estimation, and treatment of diverse wastewaters: A comprehensive review and future perspective

The application of artificial neural networks (ANNs) in the treatment of wastewater has achieved increasing attention, as it enhances the efficiency and sustainability of wastewater treatment plants (WWTPs). This paper explores the application of ANN-based models in WWTPs, focusing on the latest published research work, by presenting the effectiveness of ANNs in predicting, estimating, and treatment of diverse types of wastewater. Furthermore, this review comprehensively examines the applicability of the ANNs in various processes and methods used for wastewater treatment, including membrane and membrane bioreactors, coagulation/flocculation, UV-disinfection processes, and biological treatment systems. Additionally, it provides a detailed analysis of pollutants viz organic and inorganic substances, nutrients, pharmaceuticals, drugs, pesticides, dyes, etc., from wastewater, utilizing both ANN and ANN-based models. Moreover, it assesses the techno-economic value of ANNs, provides cost estimation and energy analysis, and outlines promising future research directions of ANNs in wastewater treatment. AI-based techniques are used to predict parameters such as chemical oxygen demand (COD) and biological oxygen demand (BOD) in WWTP influent. ANNs have been formed for the estimation of the removal efficiency of pollutants such as total nitrogen (TN), total phosphorus (TP), BOD, and total suspended solids (TSS) in the effluent of WWTPs. The literature also discloses the use of AI techniques in WWT is an economical and energy-effective method. AI enhances the efficiency of the pumping system, leading to energy conservation with an impressive average savings of approximately 10%. The system can achieve a maximum energy savings state of 25%, accompanied by a notable reduction in costs of up to 30%.

Genome and metabolome analysis of Bacillus sp. Hex-HIT36: A newly screened functional microorganism for the degradation of 1-hexadecene in industrial wastewater

1-Hexadecene has been detected at a level of mg/L in both influent and effluent of wastewater treatment plants situated in chemical/pharmaceutical industrial parks, which poses a potential threat to the environment. However, few reports are available on aerobic metabolic pathways and microorganisms involved in 1-Hexadecene degradation. In this study, a new strain of 1-Hexadecene-degrading bacteria, Bacillus sp. Hex-HIT36 (HIT36), was isolated from the activated sludge of a wastewater treatment plants located in an industrial park. The physicochemical properties and degradation efficacy of HIT36 were investigated. HIT36 was cultured on a medium containing 1-Hexadecene as a sole carbon source; it was found to remove ∼67% of total organic carbon as confirmed by mass spectrometric analysis of intermediate metabolites. Metabolomic and genomic analysis showed that HIT36 possesses various enzymes, namely, pyruvate dehydrogenase, dihydropolyhydroxyl dehydrogenase, and 2-oxoglutarate-2-oxoiron oxidoreductase (subunit alpha), which assist in the metabolization of readily available carbon source or long chain hydrocarbons present in the growth medium/vicinity. This suggests that HIT36 has efficient long-chain alkane degradation efficacy, and understanding the alkane degradation mechanism of this strain can help in developing technologies for the degradation of long-chain alkanes present in wastewater, thereby assisting in the bioremediation of environment.

Discovering transformation products of pharmaceuticals in domestic wastewaters and receiving rivers by using non-target screening and machine learning approaches

Wastewater treatment plants (WWTPs) are an important source of pharmaceuticals in surface water, but information about their transformation products (TPs) is very limited. Here, we investigated occurrence and transformation of pharmaceuticals and TPs in WWTPs and receiving rivers by using suspect and non-target analysis as well as target analysis. Results showed identification of 113 pharmaceuticals and 399 TPs, including mammalian metabolites (n = 100), environmental microbial degradation products (n = 250), photodegradation products (n = 44) and hydrolysis products (n = 5). The predominant parent pharmaceuticals (n = 37) and transformation products (n = 68) were mainly derived from antimicrobials, accounting for 32.7 % and 17.0 %, respectively. The identified compounds were found in the influent (387–428) and effluent (227–400) of WWTPs, as well as upstream (290–451) and downstream (322–416) of receiving rivers, most predominantly from antimicrobials, followed by analgesic and antipyretic drugs. A total of 399 identified TPs were transformed by 110 pathways, of which the oxidation reaction was predominant (27.0 %), followed by photodegradation reaction (10.7 %). Of the 399 TPs, 49 (with lower PNECs) were predicted to be more toxic than their parents. Compounds with potential high risks (hazard quotient >1 and risk index (RI) > 0.1) were found in the WWTP influent (126), effluent (53) and river (61), and the majority were from the antimicrobial and antihypertensive classes. In particular, the potential risks (RI) of TPs from roxithromycin and irbesartan were found higher than those for their corresponding parents. The findings from this study highlight the need to monitor TPs from pharmaceuticals in the environment.

Determination and risk assessment of UV filters and benzotriazole UV stabilizers in wastewater from a wastewater treatment plant in Lüneburg, Germany

UV filters and benzotriazole UV stabilizers are considered emerging contaminants in the environment. LC–MS/MS and GC–MS methods, involving a single solid phase extraction protocol, were developed and validated to determine eight UV filters and seven UV stabilizers, respectively in wastewater from a wastewater treatment plant (WWTP) in Lüneburg, Germany. The LC–MS/MS method exhibited extraction recoveries of ≥ 71% at six different fortification levels with limits of detection (LODs) range of 0.02 ng mL−1 – 0.09 ng mL−1. Extraction recoveries of 47 to 119% at six different fortification levels were obtained for the GC–MS method with LODs range of 0.01 – 0.09 ng mL−1. Among the UV filters, the highest mean concentration was determined for octocrylene (OCR) in influent (3.49 ng mL−1) while the highest mean concentration was measured for 2-hydroxy-4-octyloxybenzophenone (UV 531) in influent (0.44 ng mL−1) among the UV stabilizers. Potential risk to aquatic organisms was assessed by the risk quotient approach. Only OCR presented a high risk to aquatic invertebrates whereas 2-ethylhexyl 4-methoxycinnamate (EHMC) and 2-ethylhexyl salicylate (EHS) posed high risks to algae. Benzotriazole UV stabilizers presented negligible risks to aquatic invertebrates and fish. This work reports the detection of rarely studied 4-aminobenzoic acid (PABA) and UV 531 in WWTP influent and effluent. The occurrence and risk assessment of target benzotriazole UV stabilizers in wastewater from a German WWTP was demonstrated for the first time.

Biopolymeric Composite Columns for Improving Water Quality in a Freshwater Stream Receiving Wastewater Treatment Plant Effluents

Inefficiently treated wastewater, which contains a high concentration of pollutants, is hazardous when it is mixed with the clean water of rivers and lakes. Nitrate in particular is a major global problem that leads to eutrophication and poses a threat to both aquatic ecosystems and human health. To address this issue, this work assessed the efficiency of polymeric cryogel (PC) and biopolymer (EPS)-blended composites (EPS@PC) in removing nitrates. Tests were also conducted to quantify the decrease in phosphate, chloride ions, and chemical oxygen demand (COD) in real water samples taken from the Ankara stream, which receives effluents from both urban (UWTP) and industrial (IWTP) wastewater treatment plants. Five different columns with varying adsorptive properties were prepared, some of which were combined with iron. The EPS-@PC-C5 column demonstrated the highest adsorption ratio for nitrate removal compared to the other tested columns. The EPS@PC-C5 achieved a high removal efficiency of 126.38 mg nitrate/g and showed COD reduction ranging from 60.2 to 94.1%. The removal ratio of chloride concentration varied between 56.0 and 75.7%, while the removal of phosphates ranged from 87 to 99%. Columns composed of EPS (EPS@PC) with both negatively and positively charged ligands are dependable and suitable options for water remediation.Graphical

Biodegradation kinetics of organic micropollutants in biofilters for advanced wastewater treatment – Impact of operational conditions and biomass origin on removal

Biofiltration processes are often part of advanced wastewater treatment (aWWT) technologies for the removal of organic micropollutants (OMP) from conventional wastewater treatment plant (WWTP) effluents. Although biological effects are not always the main focus of these technologies (e.g. filtration through granular activated carbon), they have been shown to contribute significantly to total OMP removal. While OMP biodegradation kinetics in conventional biological wastewater treatment are well researched, no systematic comparison to biomass from aWWT is available. This biomass faces different growth conditions and higher OMP concentrations relative to the background organic matter. Adaptation to these conditions could be possible and could lead to faster OMP biodegradation kinetics, which would show in a larger pseudo first-order biodegradation kinetic constant kbiol. In this work, kbiol values for biomass obtained from aWWT biofilters were determined by evaluating OMP removals measured in lab-scale biofilters using a mechanistic model of the experimental setup. A comparison to kbiol values from literature for conventional wastewater treatment (with nutrient removal) revealed similar OMP biodegradation kinetics without any advantages of biomass from aWWT. A conceptual evaluation of influencing factors on OMP removal in biofilters showed that operational parameters (such as the biomass concentration or the empty bed contact time) and the affinity of OMPs to adsorb on biomass have a significant additional effect on biological OMP removal. Therefore, kbiol values alone are not sufficient to estimate biological OMP removal in biofilters and further information about the system is required.

Catalytic Ozonation of Pharmaceuticals Using CeO2-CeTiOx-Doped Crossflow Ultrafiltration Ceramic Membranes.

The removal of persistent organic micropollutants (OMPs) from secondary effluent in wastewater treatment plants is critical for meeting water reuse standards. Traditional treatment methods often fail to adequately degrade these contaminants. This study explored the efficacy of a hybrid ozonation membrane filtration (HOMF) process using CeO2 and CeTiOx-doped ceramic crossflow ultrafiltration ceramic membranes for the degradation of OMPs. Hollow ceramic membranes (CM) with a 300 kDa molecular weight cut-off (MWCO) were modified to serve as substrates for catalytic nanosized metal oxides in a crossflow and inside-out operational configuration. Three types of depositions were tested: a single layer of CeO2, a single layer of CeTiOx, and a combined layer of CeO2 + CeTiOx. These catalytic nanoparticles were distributed uniformly using a solution-based method supported by vacuum infiltration to ensure high-throughput deposition. The results demonstrated successful infiltration of the metal oxides, although the yield permeability and transmembrane flow varied, following this order: pristine > CeTiOx > CeO2 > CeO2 + CeTiOx. Four OMPs were examined: two easily degraded by ozone (carbamazepine and diclofenac) and two recalcitrant (ibuprofen and pCBA). The highest OMP degradation was observed in demineralized water, particularly with the CeO2 + CeTiOx modification, suggesting O3 decomposition to hydroxyl radicals. The increased resistance in the modified membranes contributed to the adsorption phenomena. The degradation efficiency decreased in secondary effluent due to competition with the organic and inorganic load, highlighting the challenges in complex water matrices.

Identifying the fate of dissolved organic matter in wastewater treatment plant effluent-dominated urban river based on fluorescence fingerprinting and flux budget approach

Effluent organic matter from wastewater treatment plants (WWTPs) is an important source of dissolved organic matter (DOM) in urban rivers worldwide and is an important water quality factor. Identifying the fate of DOM in urban river is crucial for water quality management. To address this concern, a fluorescent flux budget approach was conducted to probe the fate of DOM in WWTP effluent-dominated urban river, in combination with field measurement and fluorescence fingerprinting. An urban river receiving two WWTP effluents in Hefei City, China was chosen as the study site, where longitudinal measurements of river hydrology and water quality were performed. The fluorescence fingerprinting revealed the presence of two humic-like components (C1, C4), one fulvic-like component (C2) and one protein-like component (C3) in this investigated river, among which C2 and C4 were indicative of anthropogenic influences, closely associated with treated effluents. For each fluorescent component, the WWTP effluent contributed over 80 % of the total fluorescent dissolved organic matter (FDOM) input in this river. Using the developed FDOM flux budget model, it was found that the C1 and C3 were almost conserved within the waterbody, while the C2 and C4 experienced losses due to biogeochemical reactions. The decay rates of C2 and C4 were estimated to be 0.109–0.174 d−1 and 0.096–0.320 d−1, respectively. Spatial heterogeneity of decay rates for C2 and C4 were associated with the varied chemistries of the lateral input sources including two treated effluents and one tributary flow. Our study highlights that after treated effluent is released into the receiving waterbody, the FDOM would undergo loss from the waters particularly for anthropogenic fulvic-like substance C2 and humic-like substance C4. Additionally, the quantified FDOM decay rate in actual urban water environment provides insights for river water quality management, especially when using DOM as the surrogate indicator of organic pollutants.

Pesticides in wastewater treatment plant effluents in the Yeongsan River Basin, Korea: Occurrence and environmental risk assessment

Pesticides are among the main drivers posing risks to aquatic environments, with effluents from wastewater treatment plants (WWTPs) serving as a major source. This study aimed to identify the primary pesticides for which there was a risk of release into aquatic environments through WWTP effluents, thereby enabling more effective contamination management in public water bodies. In this study, monitoring, risk assessment, and risk-based prioritization of 87 pesticides in effluents from three WWTPs in the Yeongsan River Basin, Korea, were conducted. A total of 59 pesticides were detected at concentrations from 0.852 ng/L to 82.044 μg/L and exhibited variable patterns across different WWTP locations. An environmental risk assessment based on the risk quotient (RQ) of individual pesticides identified 13 substances implicated in significant ecotoxicological risks, as they exceeded RQ values of 1 at least once. An optimized risk (RQf)-based prioritization, considering the frequency of the measured environmental concentration (MEC) exceeding the predicted environmental concentration (PNEC), was conducted to identify pesticides that potentially posed risks and thus should be managed as a priority. Four pesticides had an RQf value >1; metribuzin exhibited the highest RQf value of 4.951, followed by 3-phenoxybenzoic acid, atrazin-2-hydroxy, and atrazine. Additionally, five pesticides (terbuthylazine, methabenzthiazuron, diuron, thiacloprid, and fipronil) and another four pesticides (propazine, imidacloprid, hexaconazole, and hexazione) had RQf values >0.1 and > 0.01, respectively. By calculating the contributions of individual pesticides to the RQf of these mixtures (RQf, mix) based on the concentration addition model, it was determined that >95 % of the sum of RQf, mix was driven by the top seven pesticides. These findings highlight the importance of prioritizing pesticides for effective management of contamination sources.

Non-target liquid chromatography high-resolution mass spectrometry screening to prioritize unregulated micropollutants that persist through domestic wastewater treatment

Efforts to regulate and monitor emerging contaminants are insufficient because new chemicals are continually brought to market, and many are unregulated and potentially harmful. Domestic wastewater treatment plants are not designed to remove micropollutants and are important sources of emerging contaminants in the aquatic environment. In this study, non-target screening, an unbiased method for analyzing compounds without prior information, was used to identify compounds that may be emitted in wastewater treatment plant effluent and should be monitored. Nine wastewater treatment plants using different treatment methods were studied, and a non-target screening data-processing method was used. The frequencies at which the contaminants were detected and contaminant persistence through the treatment processes were considered, and then the contaminants were prioritized. The predicted no-effect concentration of each prioritized contaminant was used to determine whether further analysis and monitoring of the contaminant was necessary. Quantitative analyses of five compounds (amantadine, atenolol, benzotriazole, diphenhydramine, and sulpiride) were performed using reference standards. Probable molecular formulae and structures were proposed for 17 contaminants, and the risks posed by the contaminants were estimated using predicted no-effect concentrations. The results provide valuable insights into how unregulated micropollutants can be identified and prioritized for monitoring in future studies.

Effect of chloride ions on persulfate/UV-C advanced oxidation of an alcohol ethoxylate (Brij 30)

In the present study, the effect of chloride ions on the oxidative degradation of an alcohol ethoxylate (Brij 30) by persulfate (PS)/UV-C was experimentally explored using Brij 30 aqueous solution (BAS) and a domestic wastewater treatment plant effluent spiked with Brij 30. Brij 30 degradation occurred rapidly during the early stages of oxidation without affecting the water/wastewater matrix. Mineralization of intermediates of Brij 30 degradation markedly influenced by presence of chloride ions. Chloride ions at concentrations up to 50 mg/L accelerated the mineralization through reactions involving reactive chlorine species, which reduced the sink of SO4·− by Cl− scavenging at both initial pH of 6.0 and 3.0 in the case of BAS. The fastest mineralization was achieved under acidic conditions. The WWTP effluent matrix significantly influenced mineralization efficacy of the intermediates. Co-existence of HCO3-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{HCO}}_{3}^{-}$$\\end{document} and Cl− anions accelerated the mineralization of degradation products. Organic matter originating from the WWTP effluent itself had an adverse effect on the mineralization rate. The positive effects of organic and inorganic components present in the WWTP effluent were ranked in the following order of increasing influence: (Organic matter originating from the effluent + Cl− +HCO3-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{HCO}}_{3}^{-}$$\\end{document}) < (Cl−) < (Cl− +HCO3-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{HCO}}_{3}^{-}$$\\end{document}).

Earthy/musty odour bioaccumulation in Plecoglossus altivelis grown in a land-based aquaculture fed by reclaimed secondary effluent in wastewater treatment plant

ABSTRACT Reclaimed wastewater (RWW) has been used globally for centuries, though its application in aquaculture is less extensive. Limited study has addressed impacts of RWW-derived volatile odour compounds (VOCs), such as 2,4,6-trichloroanisole (TCA), 2-methylisoborneol (MIB), and geosmin (GSM), on fish quality. This study aims to (1) assess the feasibility of reusing secondary effluent from a municipal wastewater treatment plant (WWTP) for Plecoglossus altivelis aquaculture in a land-based flow-through system and (2) evaluate the sensory effects of selected VOCs on fish quality. Results showed that increased temperature and ammonia levels in summer RWW negatively affected fish growth, while autumn RWW did not. Heavy metals in fish did not cause health issues. TCA, MIB, and GSM concentrations in fish tissues were 4.7–5.7, 0.3–40.5, and 1.1–1.9 mg kg−1, respectively. TCA emerged as the most concerning odorant, with higher relative odour intensity than MIB and GSM in RWW-cultured fish, regardless of seasonal change. This study is the first to report on a self-constructed aquaculture system using RWW at a WWTP, recommending effective VOC and ammonia removal for sustainable RWW use in aquaculture. Additionally, the study highlighted TCA's impact as an anthropogenic indicator in aquatic environments amid increasing WWTP prevalence in developed cities.

Exploring spatial and temporal symptoms of the freshwater salinization syndrome in a rural to urban watershed

The freshwater salinization syndrome (FSS), a concomitant watershed-scale increase in salinity, alkalinity, and major-cation and trace-metal concentrations, over recent decades, has been described for major rivers draining extensive urban areas, yet few studies have evaluated temporal and spatial FSS variations, or causal factors, at the subwatershed scale in mixed-use landscapes. This study examines the potential influence of land-use practices and wastewater treatment plant (WWTP) effluent on the export of major ions and trace metals from the mixed-use East Branch Brandywine Creek watershed in southeastern Pennsylvania, during the 2019 water year. Separate analysis of baseflow and stormflow subsets revealed similar correlations among land-use characteristics and streamwater chemistry. Positive associations between percent impervious surface cover, which ranged from 1.26 % to 21.9 % for the 13 sites sampled, and concentrations of Ca2+, Mg2+, Na+, and Cl− are consistent with road-salt driven reverse cation exchange and weathering of the built environment. The relative volume of upstream WWTP was correlated with Cu and Zn, which may be derived in part from corroded water-conveyance infrastructure; chloride to sulfate mass ratios (CSMR) ranged from ~6.3 to ~7.7× the 0.5 threshold indicating serious corrosivity potential. Observed exceedances of U.S. Environmental Protection Agency Na+ and Cl− drinking water and aquatic life criteria occurred in winter months. Finally, correlations between percent cultivated cropland and As and Pb concentrations may be explained by the persistence of agricultural pesticides that had been used historically. Study results contribute to the understanding of FSS solute origin, fate, and transport in mixed-use watersheds, particularly those in road salt-affected regions. Study results also emphasize the complexity of trace-metal source attribution and explore the potential for FSS solutes to affect human health, aquatic life, and infrastructure.

Evaluation of microplastic particle transmission in a microfiltration process using fluorescence measurements: Effect of pore size and flux

Microplastic (MP) pollution in the aquatic environment is widespread, with a significant fraction of these particles originating from municipal wastewater treatment plant (WWTP) effluents. Whereas membrane filtration processes are touted as an effective MP removal strategy, the rejection of irregularly-shaped plastic particles, similar to those found in WWTPs, is poorly understood. Here, we characterize the filtration of irregularly-shaped MP particles (∼10 μm) through Durapore® microfiltration membranes (0.45 and 5 μm pore sizes). These particles were produced via ball-milling/sieving processes from a fluorescent polyethylene feedstock, enabling particle concentrations to be quantified using a standard fluorometric plate reader. Permeate samples from the 0.45 μm membrane exhibited low fluorescent intensities relative to feed samples, implying minimal MP transmission. Conversely, appreciable MP transmission through the 5 μm membrane was noted, with sizable MPs (∼2–7 μm) found in the permeate. This transmission was exacerbated at higher fluxes which emphasizes how operating conditions can govern MP retention. Post-filtration analyses demonstrated that particle capture occurred largely at the feed-membrane interface, where greater MP intrusion into the membrane was seen at the larger pore size. These results reaffirm the importance of choosing an appropriate membrane/membrane pore size and operating conditions to maximize MP retention in WWTPs.