Wastewater Treatment Plant Discharge Research Articles

Microplastics and Endocrine Disruptors in Typical Wastewater Treatment Plants in Megacity Shanghai

The fast development of China’s urbanization has led to a notable release of emerging pollutants, including microplastics (MPs) and endocrine disruptors (EDCs). Generally, these pollutants enter the coastal environment through the discharge of wastewater treatment plants (WWTPs) and finally threaten the organisms in the receiving waterbody. The study investigated the environmental behavior of MPs and EDCs in two typical WWTPs in one of the megacities in China, Shanghai. The abundance of MPs in the influent ranged from 321 to 976 items/L. Four shapes (films, fragments, fibers, and microbead) were found, while fibers and films dominated. Transparent (31–63%) and white (20–47%) MPs were more frequently observed, while polyethylene terephthalate, cellulose, and cellophane were the main polymetric materials. The size of the MPs fell between 15.8 μm and 2220 μm, and the smaller one (<500 μm) dominated. The removal efficiencies of the two WWTPs for MPs ranged from 64% to 92%, and both WWTPs performed better for large pieces of MPs (>500 μm). For EDCs, total concentrations in the influent were detected, ranging from 113 to 2780 ng/L. Two groups, including phenolic estrogens (PEs) and steroid estrogens (SEs), were detected, and PEs, especially bisphenol A (BPA), were the predominant individuals among the studied EDCs. Specifically, PEs ranged from 82.8 to 2637 ng/L, while SEs ranged from 27.3 to 143 ng/L. The removal efficiencies of the WWTPs for EDCs varied (82.8–100%) as well, possibly due to the different treatment compartments and contamination load in the influent. Seasonal variations for both MPs and EDCs were observed. Specifically, concentrations of MPs and EDCs in WWTPs influent were higher in the wet season, as well as the removal efficiency. Furthermore, there was a correlation observed between the concentrations of MPs and EDCs, suggesting that MPs and EDCs may originate from the same source and that EDCs released by MPs cannot be ignored during treatment. Finally, the study evaluated the environmental risk of the effluents. MPs led to a minor risk (Level I), while EDCs might lead to an adverse impact on algae (RQs = 0.0014–0.024) and fish (RQs = 3.4–30.2). In summary, WWTPs received considerable amounts of MPs and EDCs. Although the WWTPs removed the contaminants efficiently, the environmental risk of the effluent needs to be noted.

Potential effects of the discharge of wastewater treatment plant (WWTP) effluents in benthic communities: evidence from three distinct WWTP systems.

Wastewater treatment plant (WWTP) effluents can be sources of environmental contamination. In this study, we aimed to understand whether effluents of three different WWTPs may have ecological effects in riverine recipient ecosystems. To achieve this, we assessed benthic phytobenthos and macroinvertebrate communities at three different locations relative to the effluent discharge: immediately upstream, immediately downstream and 500-m downstream the effluent discharge. Two approaches were employed: the ecological status classification as defined in the Water Framework Directive (WFD) based on biological indicators; constrained multivariate analysis to disentangle the environmental drivers (physicochemical variables and contaminants, namely metals, polycyclic aromatic hydrocarbons, pharmaceuticals, and personal care products) of ecological changes across the study sites. The results showed inconsistencies between the WFD approach and the multivariate approach, as well as between the responses of macroinvertebrates and diatoms. The WWTP effluents impacted benthic communities in a single case: macroinvertebrates were negatively affected by one of the WWTP effluents, likely by the transported pharmaceuticals (other stressors are essentially homogeneous among sites). Given the findings and the scarcity of consistent evidence on ecological impacts that WWTP effluents may have in recipient ecosystems, further research is needed towards more sustainable regulation and linked environmental protection measures.

Microplastic contamination in urban aquatic environments: Occurrence characteristics in urban streams and stormwater runoff from urban surfaces

This study investigates microplastics in urban environments, focusing on their abundance, types, and relationships with hydrological parameters. Microplastic analyses encompassed two steps: (1) examining urban streams including discharges from a wastewater treatment plant (WWTP) during non-rainy seasons, and (2) analyzing stormwater runoff from urban surfaces for microplastic content during rainy seasons. In urban streams, WWTP discharge exhibited higher microplastic concentrations compared to other streams, indicating WWTP discharge is a dominant source of microplastic pollution. The most prevalent microplastics detected were polypropylene, polyethylene, and their copolymer, although a variety of other types were also found. Concentrations of microplastics were notably influenced by specific urban land uses, as evidenced by a strong correlation (0.95) between microplastic concentrations and areas characterized by industrial and transportation activities. During rainy seasons, microplastics followed the pattern of stormwater runoff, but the highest concentrations, significantly exceeding those in urban streams, were observed before the peak runoff. These maximum concentrations and their timing of occurrence were linked to antecedent dry days, rain intensity, and runoff rate, showing significant statistical correlations. Regardless of their sizes, a diverse range of microplastic types was identified in these conditions, with no consistent pattern across different rain events. This highlights the complex nature of urban microplastic pollution. This study reveals that aquatic ecosystems are significantly affected by two primary factors: (1) the consistent contribution of microplastics from WWTP discharges, and (2) the short-term, but severe, impacts of microplastic pollution associated with stormwater runoff. Furthermore, it suggests the development of alternative strategies to mitigate microplastic pollution in aquatic ecosystems, informed by the findings on the characteristics of microplastics in urban environments. This research underscores the urgent need for integrated urban environmental management strategies, paving the way for future studies to further explore and address the multifaceted challenges posed by microplastic pollution in aquatic ecosystems.

Evidence of deviations between experimental and empirical mixing lengths: Multi-discharge field tests in an arid river system

Despite advances in wastewater treatment plant (WWTP) efficiencies, multiple contaminants of concern, such as microplastics, pharmaceuticals, and per- and poly-fluoroalkyl substances (PFAS) remain largely untreated near discharge points and can be highly concentrated before they are fully mixed within the receiving river. Environmental agencies enforce mixing zone permits for the temporary exceedance of water quality parameters beyond targeted control levels under the assumption that contaminants are well-mixed and diluted downstream of mixing lengths, which are typically quantified using empirical equations derived from one-dimensional transport models. Most of these equations were developed in the 1970s and have been assumed to be standard practice since then. However, their development and validation lacked the technological advances required to test them in the field and under changing flow conditions. While new monitoring techniques such as remote sensing and infrared imaging have been employed to visualize mixing lengths and test the validity of empirical equations, those methods cannot be easily repeated due to high costs or flight restrictions. We investigated the application of Lagrangian and Eulerian monitoring approaches to experimentally quantify mixing lengths downstream of a WWTP discharging into the Rio Grande near Albuquerque, New Mexico (USA). Our data spans river to WWTP discharges ranging between 2-22x, thus providing a unique dataset to test long-standing empirical equations in the field. Our results consistently show empirical equations could not describe our experimental mixing lengths. Specifically, while our experimental data revealed “bell-shaped” mixing lengths as a function of increasing river discharges, all empirical equations predicted monotonically increasing mixing lengths. Those mismatches between experimental and empirical mixing lengths are likely due to the existence of threshold processes defining mixing at different flow regimes, i.e., jet diffusion at low flows, the Coanda effect at intermediate flows, and turbulent mixing at higher flows, which are unaccounted for by the one-dimensional empirical formulas. Our results call for a review of the use of empirical mixing lengths in streams and rivers to avoid widespread exposures to emerging contaminants.

Coupling hydrological and sanitation datasets to simulate wastewater-derived contamination in European rivers: model development and calibration

Wastewater treatment plant (WWTP) discharges of microcontaminants negatively impact freshwater streams, underscoring the need for accurately mapping wastewater-derived contamination in water bodies across Europe (EU). In this study, we present a fast and open-source code for a microcontaminants fate and transport (MFT) model, capable of simulating contamination at a high resolution (15 arc second scale) across the EU. The model was developed using the best publicly available hydrological (HydroSHEDS) and sanitation (UWWTD) datasets and was rigorously calibrated, with a goodness of fit of 77.5% as measured by the . Importantly, the model demonstrated the ability to predict wastewater-derived contamination in water bodies, making it a valuable tool for planning the upgrade of WWTPs and improving the ecological condition of freshwater streams in the EU.

Microparticles in Wild and Caged Biota, Sediments, and Water Relative to Large Municipal Wastewater Treatment Plant Discharges.

Anthropogenically modified microparticles including microplastics are present in municipal wastewater treatment plant (WWTP) effluents; however, it is unclear whether biotic exposures are elevated downstream of these outfalls. In the fall of 2019, the present study examined whether microparticle levels in resident fish, environmental samples, and caged organisms were elevated near the Waterloo and Kitchener WWTP outfalls along the Grand River, Ontario, Canada. Wild rainbow darters (Etheostoma caeruleum) were collected from a total of 10 sites upstream and downstream of both WWTPs, along with surface water and sediment samples to assess spatial patterns over an approximately 70-km river stretch. Amphipods (Hyalella azteca), fluted-shell mussels (Lasmigona costata), and rainbow trout (Oncorhynchus mykiss) were also caged upstream and downstream of one WWTP for 14 or 28 days. Whole amphipods, fish digestive tracts, and mussel tissues (hemolymph, digestive glands, gills) were digested with potassium hydroxide, whereas environmental samples were processed using filtration and density separation. Visual identification, measurement, and chemical confirmation (subset only) of microparticles were completed. Elevated abiotic microparticles were found at several upstream reference sites as well as at one or both wastewater-impacted sites. Microparticles in amphipods, all mussel tissues, and wild fish did not show patterns indicative of increased exposures downstream of effluent discharges. In contrast, elevated microparticle counts were found in trout caged directly downstream of the outfall. Across all samples, cellulose fibers (mainly blue and clear colors) were the most common. Overall, results suggest little influence of WWTP effluents on microparticles in biota but rather a ubiquitous presence across most sites that indicates the importance of other point and nonpoint sources to this system. Environ Toxicol Chem 2024;00:1-15. © 2024 His Majesty the King in Right of Canada and The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. Reproduced with the permission of the Minister of Environment and Climate Change Canada.

Hidden threats in the plastisphere: Carbapenemase-producing Enterobacterales colonizing microplastics in river water

Carbapenem resistance poses a significant burden on healthcare systems worldwide. Microplastics (MPs) have emerged as potential contributors to antibiotic resistance spread in the environment. However, the link between MPs and carbapenem resistance remains unexplored. We investigated the prevalence of carbapenem-resistant bacteria colonizing MPs placed in a river. Three replicates of a mixture of polypropylene (PP), polyethylene (PE) and polyethylene terephthalate (PET) and of PET alone were placed both upstream and downstream a wastewater treatment plant (WWTP) discharge. Carbapenem-resistant Enterobacterales (CRE) were further characterized by phenotypic tests and whole-genome sequencing. The abundance of carbapenem-resistant bacteria on MPs increased significantly downstream the WWTP. Their prevalence was higher in the MPs mixture compared to PET alone. CRE strains colonizing MPs included Klebsiella pneumoniae (n = 3), Klebsiella quasipneumoniae (n = 3), Raoultella ornithinolytica (n = 2), Enterobacter kobei (n = 1) and Citrobacter freundii (n = 1), most (n = 8) recovered after the WWTP discharge. All strains exhibited at least one of the tested virulence traits (biofilm formation at 37 °C, haemolytic activity and siderophore production), were multi-drug resistant and carried carbapenemase-encoding genes [blaKPC-3 (n = 5), blaGES-5 (n = 2) or blaKPC-3 + blaGES-5 (n = 3)]. Uncommon phenotypes of resistance to imipenem/relebactam (n = 3) and ceftazidime/avibactam (n = 2) were observed. Two blaKPC−3-positive K. pneumoniae successfully transfer this gene trough conjugation. Genome analysis predicted all strains as human pathogens. The blaKPC−3 was associated with the Tn4401d transposon on a pBK30683-like plasmid in most of the isolates (n = 7). The blaGES-5 was mostly linked to class 3 integrons. A K. pneumoniae strain belonging to the outbreak-causing high-risk clone ST15 carried both blaKPC-3 and blaCTX-M-15. Two K. quasipneumoniae isolates carried the plasmid-mediated colistin resistance gene mcr-9. Our results underscore the role of MPs as vectors for CRE dissemination, particularly following WWTPs discharges. MPs may act as carriers, facilitating the dissemination of carbapenemase-encoding genes and potentially contributing to increased CRE incidence in the environment.

The fate of antibiotic resistance genes in wastewater containing microalgae treated by chlorination, ultra-violet, and Fenton reaction

Antibiotic resistance genes (ARGs) and bacteria (ARBs) in the effluent of wastewater treatment plants (WWTPs) are of utmost importance for the dissemination of ARGs in natural aquatic environments. Therefore, there is an urgent need for effective technologies to eliminate WWTP ARGs/ARBs and mitigate the associated risks posed by the discharged ARG in aquatic environments. To test the effective technology for eliminating ARGs/ARBs, we compared the removal of ARGs and ARBs by three different tertiary treatments, namely ultra-violet (UV) disinfection, chlorination disinfection, and Fenton oxidation. Then, the treated wastewater was co-cultured with Chlorella vulgaris (representative of aquatic biota) to investigate the fate of discharged ARGs into the aquatic environment. The results demonstrated that chlorination (at a chlorine concentration of 15 mg/L) and Fenton (at pH 2.73, with 0.005 mol/L Fe2+ and 0.0025 mol/L H2O2) treatment showed higher efficacy in ARG removal (1.8 - 4.17 logs) than UV treatment (15 min) (1.29 - 3.87 logs). Moreover, chlorine at 15 mg/L and Fenton treatment effectively suppressed ARB regeneration while UV treatment for 15 min could not. Regardless of treatments tested in this study, the input of treated wastewater to the Chlorella system increased the number of ARGs and mobile genetic elements (MGEs), indicating the potential risk of ARG dissemination associated with WWTP discharge. Among the wastewater-Chlorella co-culture systems, chlorination resulted in less of an increase in the number of ARGs and MGEs compared to Fenton and UV treatment. When comparing the wastewater systems to the co-culture systems, it was observed that Chlorella vulgaris reduced the number of ARGs and MGEs in chlorination and UV-treated wastewater; however, Chlorella vulgaris promoted ARG survival in Fenton-treated water, suggesting that aquatic microalgae might act as a barrier to ARG dissemination. Overall, chlorination treatment not only effectively removes ARGs and inhibits ARB regeneration but also shows a lower risk of ARG dissemination. Therefore, chlorination is recommended for practical application in controlling the spread of discharged ARGs from WWTP effluent in natural aquatic environments.

Land cover, stream discharge, and wastewater effluent impacts on baseflow sediment and nutrient concentrations in SW Ohio streams

AbstractElevated nutrient and suspended sediment concentrations often result in negative environmental impacts within freshwater environments. Studies that directly compare suspended sediment and bioavailable nutrients between predominantly agricultural and predominantly urban watersheds during baseflow conditions are largely lacking. The purpose of this study was to determine the impacts of land cover, stream discharge, and wastewater treatment plant (WWTP) discharge on nutrient and sediment concentrations, across a large land cover gradient in Southwest Ohio streams. Weekly baseflow samples were collected from eight streams over 1 year from November, 2016 through November, 2017. Total suspended sediment, nitrate, and phosphate concentrations were measured. Results indicate that agricultural land cover and WWTPs increase nitrate and phosphate concentrations in the study area. Total suspended sediment and nitrate concentrations increased with discharge, and discharge was a relatively weak predictor of phosphate concentrations. Seasonal water quality trends varied by parameter and land use also had unique impacts on seasonal water quality trends. Results suggest that to improve water quality in the study area, efforts should focus on improving WWTP effluent treatment and agricultural land management.

Conflict between urbanization and water environmental protection: Lessons from the Xiangjiang River Basin in China

China, the largest developing country, has experienced rapid urbanization since its reform and opening-up. However, the increasing pollution load from urban areas has deteriorated urban river water quality, contradicting the concept of sustainable and green development promoted by the Chinese government. This situation elucidates governmental shortcomings in systematic environmental protection. Our study revealed that the current wastewater treatment plant (WWTP) discharge standards in urban areas are insufficient for attaining the desired urban river water quality and thus intensify the conflict between urbanization and water environmental protection. As urbanization continues, the urban population will grow, further exacerbating pollution and conflict. Our focus was the Xiangjiang River basin in Zunyi, a typical urbanized city in China. Using a validated one-dimensional mathematical model, we compared the water quality in the Xiangjiang River between current and upgraded WWTP discharge standards. The results showed that the water quality in the Xiangjiang River falls short of the standards, with more than 60 % of the river exceeding limits. However, upgrading WWTP discharge standards significantly reduces the proportion of river sections exceeding limits, with only 0.4 % exceeding standards during specific periods. This enhancement greatly improved the Xiangjiang River's water quality, aided in restoring the entire water environment in the basin, and supported water environmental protection goals. Our research findings offer crucial support for local governments in shaping comprehensive water environmental protection policies and insights for addressing similar environmental challenges caused by rapid urbanization in other developing regions.

The COVID-19 Pandemic Impact of Hospital Wastewater on Aquatic Systems in Bucharest

The COVID-19 pandemic reshaped the global response to a pandemic, including the way of using chemical compounds such as disinfectants and antibiotics. The large-scale use of antibiotics and disinfectants during the COVID-19 pandemic caused environmental pressure not only due to the chemicals themselves but also due to their effect on bacterial communities, inducing resistance to chemicals and changing the population structure of bacterial communities, especially in aquatic environments. The dissemination of fecal bacteria, including antibiotic-resistant bacteria, and pathogens from hospital wastewater into the environment, via wastewater treatment plants (WWTPs), triggered the premises of a major public health issue. Rivers flowing through cities are natural streams for WWTP discharges, and they directly bear the impact of anthropic activities, disseminating domestic and industrial pollution over large areas. The aim of the present study was to assess the microbiological bacterial structure of municipal and hospital wastewaters as well as their impact on natural streams, covering the pre-to post-COVID-19 pandemic period of time. The results indicated that the COVID-19 pandemic had a direct impact on hospital wastewater microbiological quality and the environment due to an excessive use of antibiotics and disinfectants. In addition, the constant presence of antibacterial compounds increased the rate of bacterial selection and induced population structural changes in the bacterial communities from aquatic systems.

Transcriptomic profiles of brains in juvenile Atlantic cod (Gadus morhua) exposed to pharmaceuticals and personal care products from a wastewater treatment plant discharge

Pharmaceuticals and personal care products (PPCPs) are frequently detected in marine environments, posing a threat to aquatic organisms. Our previous research demonstrated the occurrence of neuroactive compounds in effluent and sediments from a wastewater treatment plant (WWTP) in a fjord North of Stavanger, the fourth-largest city in Norway. To better understand the influence of PPCP mixtures on fish, Atlantic cod (Gadus morhua) were caged for one month in 3 locations: site 1 (reference), site 2 (WWTP discharge), and site 3 (6.7 km west of discharge). Transcriptomic profiling was conducted in the brains of exposed fish and detection of PPCPs in WWTP effluent and muscle fillets were determined. Caffeine (47.8 ng/L), benzotriazole (10.9 ng/L), N,N-diethyl-meta-toluamide (DEET) (5.6 ng/L), methyl-1H-benzotriazole (5.5 ng/L), trimethoprim (3.4 ng/L), carbamazepine (2.1 ng/L), and nortriptyline (0.4 ng/L) were detected in the WWTP effluent. Octocrylene concentrations were observed in muscle tissue at all sites and ranged from 53 to 193 ng/g. Nervous system function and endocrine system disorders were the top enriched disease and function pathways predicted in male and female fish at site 2, with the top shared canonical pathways involved with estrogen receptor and Sirtuin signaling. At the discharge site, predicted disease and functional responses in female brains were involved in cellular assembly, organization, and function, tissue development, and nervous system development, whereas male brains were involved in connective tissue development, function, and disorders, nervous system development and function, and neurological disease. The top shared canonical pathways in females and males were involved in fatty acid activation and tight junction signaling. This study suggests that pseudopersistent, chronic exposure of native juvenile Atlantic cod from this ecosystem to PPCPs may alter neuroendocrine and neuron development.

Combined Effects of Fronts, Upwelling and the Biological Pump on Organophosphate Esters in the Changjiang (Yangtze) River Estuary During Summer

AbstractEstuarine and coastal environments are important transport pathways and regional sinks for anthropogenic pollutants. In this study, the occurrence and transport of the continuously released organophosphate esters (OPEs) was investigated together with physical and biochemical parameters throughout the water column in the Changjiang (Yangtze) River estuary during the summer. Total dissolved and particulate OPEs showed great spatial heterogeneity, with mean concentrations of 550 ± 280 ng/L in the estuary, 110 ± 270 ng/L in the front/upwelling zone, and 410 ± 450 ng/L in the continental shelf. OPE concentrations in the estuarine bottom waters were high due to massive terrestrial/sediment inputs. In contrast, the “surface enrichment and depth depletion” of OPEs in the continental shelf was closely related to seasonal stratification. Reduced OPE concentrations were observed in the frontal/upwelling zone due to isopycnal heaving. Frontal activity and upwelling induced phytoplankton blooms in the coastal regions, which jointly contributed to elevated OPEs beneath surface water with high phytoplankton aggregation. The OPEs mainly originated from wastewater treatment plant discharges, industrial pollution and consumer products. These OPEs generally posed a low ecological risk to aquatic lives, but their long‐term effects cannot be ignored due to their continuous high production, usage and release.

Removal of most frequent microplastic types and sizes in secondary effluent using Al2(SO4)3: choosing variables by a fuzzy Delphi method

Microplastics (MPs) as an emerging pollutant can affect aquatic organisms through physical ingestion, chemical problems and possible creation of biological layers on their surfaces in the environment. One of the significant ways for MPs to enter the aquatic environment is through the effluent discharge of wastewater treatment plants (WWTPs). In this study, first, the concentration and characteristics of MPs in secondary wastewater effluent, and the influential variables related to the coagulation process, for MPs removal were identified using systematic reviews of previous studies. Then, the most proper MPs characterization and coagulation variables were chosen by experts’ opinions using a fuzzy Delphi method. Therefore, the experiment tested in conditions close to the full-scale wastewater treatments. Finally, in the laboratory removal of MPs by coagulation of polyamide (PA), polystyrene (PS), and polyethylene (PE), < 125 and 300–600 μm in size, was tested by a jar test applying Al2(SO4)3 in doses of 5 to 100 mg/L plus 15 mg/L polyacrylamide as a coagulant aid. Using R and Excel software, the results were analyzed statistically. It was concluded that the maximum and minimum removal efficiency was 74.7 and 1.39% for small PA and large PE, respectively. Smaller MPs were found to have higher removal efficiency. The MPs type PA achieved greater removal efficiency than PS, while PE had the least removal efficiency.

Sedimentary abundance and major determinants of river microplastic contamination in the central arid part of Iran

The proliferation of anthropogenic activities around the Central Iranian Rivers shows a warning alarm of river microplastic (MP) pollution. In the Zayandeh-rood River, the mean abundance of sedimentary MPs trapped at the mouth of 21 modified sub-catchments was 588 items/kg d.w and followed the order: downstream (1701 items/kg d.w) > midstream (269.2 items/kg d.w) > upstream (57.2 items/kg d.w). The widespread distribution of fiber and fragment forms across all stations and the high MP abundance near the discharge of the largest wastewater treatment plant indicate their origin from both point and non-point sources. Using the linear multiple linear regression (MLR) and nonlinear artificial neural network (ANN), we assessed the contribution of three types of variables including the sediment physio-chemical properties, river geometry and land-use characteristics. According to both modeling results, the mean annual number of local people and tourist visitors (0.35 million people) are the most important determinants of river MP pollution whose contribution dominates through the use of plastic products and their direct and indirect release into the environment. The ANN model (R2 = 0.99) outperformed the MLR model (R2 = 0.80) and showed the importance of total organic carbon (TOC)-rich regions as MP hotspots. To alleviate the river MP pollution, suggested measures involve altering plastic usage and disposal practices among visitors and reducing the TOC content in the industrial/municipal wastewater entering the river.

Ammonium concentration in stream sediments resulting from decades of discharge from a wastewater treatment plant

A study of ammonium pollution in the sediments of a stream that receives wastewater treatment plant (WWTP) discharge has been carried out. It is urgently necessary to find environmental indicators that can help prevent and detect potential contamination of water, as water is an increasingly scarce resource. To understand the behaviour of ammonium ions introduced by a historical (50-year) contamination process, vertical boreholes were drilled in the stream banks to depths between 30 and 120 cm. Moisture, pH, ammonium (soluble and exchangeable), and clay fraction content were analysed. The variation profile of these parameters was evaluated as a function of depth to determine factors related to the distribution of ammonium in several locations along the stream banks.The ammonium concentration was asymmetrically distributed among samples collected in near-surface locations, with ammonium concentrations between 0.3048 mmol/kg soil and 0.0007 mmol/kg soil. Ammonium was typically concentrated at sediment depths of 30–40 cm, which also exhibited the highest clay fraction content. High positive correlations were detected (r > 0.8; p < 0.0001) among the different ammonium variables (exchanged and dissolved species). No contamination effect was observed below 60–70 cm depth, which was due to ammonium retention in a natural barrier layer of clayey sediment.The clays in our study area (previously identified as smectite, a 2:1 sheet silicate) were able to control the contamination by retaining ammonium in the interlayers, which retarded nitrification. It is suggested that clay could serve as a geo-indicator of ammonium pollution evolution.

Microplastics in the Syr Darya River Tributaries, Uzbekistan

The objective of the study was a pre-screening of the microplastic (MP) content in surface water and benthic sediments of Kara Darya and Chirchiq rivers, the first-order tributaries of the Syr Darya River (Uzbekistan). For the first time, surface water and benthic sediment samples were taken from this region, and quantitative screening of MPs 0.15–5.00 mm in size was performed. A combined visual and μRaman-based methodology was used to quantify and characterize artificial polymer microparticles from the surface water and bottom sediments of two rivers. The average abundance of MPs in the Kara Darya River and Chirchiq River waters was found to be 4.28 ± 0.09 and 0.95 ± 0.36 items per m3, and that in benthic sediments attained 244 ± 28.9 and 333 ± 11.5 items per kg of dry soil, respectively. MP concentration in surface water and benthic sediments of the Kara Darya River significantly exceeded (p-value &lt; 0.01) that in the Chirchiq River. Microfibers were most abundant; the proportion of MP fibers in the water of the Kara Darya and Chirchiq rivers amounted to 89 and 95%, respectively, and that in benthic sediments of the rivers was 86 and 84%, respectively. The dominance of microfibers may indicate the route of entry to the rivers through domestic wastewater treatment plant discharges. The polymer microparticles in the surface water and benthic sediments of the Kara Darya and Chirchiq rivers were mainly represented by polyethylenterephtalate (PET), which accounted for half of all MPs detected in the Kara Darya River. Microparticles of textile origin were particularly abundant in the Kara Darya River, where viscose and nylon fibers were also found, which suggests the leading role of synthetic textiles in the pollution. The reported data are the first experimental evidence of MP pollution of the Syr Darya tributaries, but the distribution and circulation of MPs in surface water in Central Asia requires further comprehensive studies.

Co-transport of Microplastics and a surrogate for Human Enteric Viruses in a saturated column packed with Quartz Sand

Groundwater can be contaminated with infective human enteric viruses from various sources, such as wastewater treatment plant discharge, landfills, septic tanks, agricultural practices, and artificial groundwater recharge. Anthropogenic pollutants, such as microplastics, may exhibit an affinity to transport biocolloids (bacteria, viruses) further and reduce their degradation rates in the natural environment. Human enteric viruses (poliovirus, hepatitis A, rotavirus, and adenovirus) can adsorb to the abiotic surface of microplastics and are simultaneously present in wastewater discharge. These newly formed clumps of pathogens and microplastics could penetrate deeper into soils as vectors for preferential flow and threaten groundwater systems, triggering a higher risk for drinking water and possibly followed by a disease outbreak. The mechanisms behind the adsorption of human enteric viruses on microplastic surfaces and their potential role in prolonging virus survival and promoting environmental transport remain unclear. This study aims to explore the possibility of co-transport of microplastics and human enteric viruses in saturated porous media, using PRD1 bacteriophage as a surrogate. PRD1 bacteriophages have been widely used as surrogates of rotavirus because they share many fundamental properties and features. Column experiments were performed using quartz sand (soil grain size: 0.60 - 1.30 mm) as a porous media in a 30 cm long and 7 cm diameter column. The column experiments were conducted by maintaining Darcy velocity of 2.65 m/day. Three different influent solution scenarios were considered in the experiments: PRD1 mixed with microplastics, PRD1 alone, and microplastics alone. The enumeration of PRD1 in the effluent solution was performed using quantitative polymerase chain reaction (qPCR) as well as the culture method, in order to differentiate between infective and inactive virus transport. Microplastics were quantified using Solid-Phase Cytometry (SPC). Results were analyzed by calculating the collision and sticking efficiencies of the microplastics and PRD1 using the classical colloid filtration theory and Hydrus 1D modeling tool. There was no evidence of interference or inhibition of microplastics on the performance of qPCR and DNA extraction in the methodological setup. Additionally, the efficacy of qPCR and DNA extraction methods did not yield significantly different results across any of the influent solution conditions. Preliminary results suggest that the presence of microplastics enhanced the transport of PRD1, which led to reduced attachment of PRD1 in the porous media. The concentration of infective phages showed a delayed sharp increase, indicating that there may be a sorption mechanism that delays their breakthrough. It is possible that a portion of the active phages possess a higher sticking efficiency and that population heterogeneity contributes to this phenomenon. A comprehensive understanding of the processes that govern virus transport with globally distributed microplastics is crucial for protecting public health.

The Potential Impacts of Statins and Beta-Blockers on West Virginia Ichthyofauna

Pharmaceuticals and personal care products (PPCPs), such as statins and beta-blockers, are commonly used to treat cardiovascular disease in adults. Active versions of these pharmaceuticals and their various metabolites enter surface waters via wastewater treatment plant (WWTP) discharge, as well as from other point sources. Sub-lethal effects of statins and beta-blockers on wild fish at environmental concentrations have been understudied up to this point. The objectives of this study were to use several health condition metrics and determine if there was a relationship between fish condition and environment concentrations of statins and beta-blockers near two West Virginia WWTPs. Water samples were collected from upstream, downstream, and effluent pipe from August to November 2022, and analyzed for atorvastatin, simvastatin, metoprolol, and carvedilol via liquid chromatography with tandem mass spectrometry. Fish were sampled upstream, at the discharge, and downstream of each WWTP in November 2022. Fish health was assessed with three metrics: relative weight (Wr), hepatosomatic index (HSI), and gonadosomatic index (GSI). ANOVAs were used to assess differences among the health metrics based on sex, genus/species, and location relative to WWTPs. Additionally, changes in Wr relative to surface water concentrations of statins and beta-blockers was modeled with a Bayesian linear mixed effects model, with surface water concentrations as fixed effects with a random slope, while the section and genus parameters were treated as random intercepts. Surface concentrations for atorvastatin (0.47–4.36 ng/L), simvastatin (0.27–0.95 ng/L), metoprolol (2.80–21.01 ng/L), and carvedilol (0.43–0.90 ng/L) varied across sampling sections. HSI based on sex and species were nearly significant. GSI was significantly higher in females. Wr differed among genera, as well as the interaction between genus and sample section (p &lt; 0.001). Fixed effects from the linear mixed effects model showed Wr was negatively related to simvastatin (−0.139 [−2.072–1.784]) and carvedilol (−0.262 [−2.164–1.682]) while atorvastatin (0.207 [−1.371–1.845]) and metoprolol (0.052 [−0.533–0.584]) were positively related to Wr. Individual genera responded differently to each pharmaceutical based on location, indicating that it is likely that other factors were also influencing the fish health metrics. Further research targeting individual tissues and controlled experiments with different exposure regimes will be required to further enlighten the long-term effects of cardiovascular PPCPs on fish health.

Modelling micropollutant cycle in Lake Como in a winter scenario: Implications for water use and reuse, ecosystem services, and the EU zero pollution action plan

The fate and effects of 42 pharmaceuticals was studied in Lake Como (Italy), in wastewater treatment plants delivering water to the lake, in two rivers and in potable water obtained from lake water. Lake Como is one of the deepest and largest lakes in Northern Italy, serving important ecosystem services (i.e., drinking water, recreational, industrial, irrigation uses), some of which are currently at risk giving the current water scarcity and climate change scenarios. The highest concentrations measured in lake water were those of diclofenac, followed by carbamazepine, its metabolite, and clarithromycin. The data measured allowed to calibrate and run a fugacity-based lake model, which showed that the most important chemical load generally comes from the advective water from the north of the lake, rather than from the direct wastewater treatment plant (WWTP) discharges. This indicates that only an important reduction of chemical discharge (reduced use or extensive treatment) at a drainage basin level could significantly reduce concentrations in water. This has strong implications on how to implement the EU zero pollution action plan to significantly improve water ecosystem and human health protection.