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The emergence and dissemination of mcr-1-positive Escherichia coli (MCRPEC) represent a critical public health threat. Here, we conducted a prospective analysis of MCRPEC isolates from wastewater treatment plants (WWTPs), local residents' fecal (LRF), and international airplane waste (IAW) to investigate their genetic characteristics and transmission patterns circulating in human-environment domains. The MCRPEC prevalence was 2.43 % in WWTPs, 1.37 % in IAW and 0.69 % in LRF. MCRPEC showed substantial genetic diversity, encompassing 61 sequence types (primarily ST1011, ST101, and ST2705), 7 plasmid types (primarily IncI2), 8 phylogroups (primarily A and B1), 9 mcr-1-flanked lineages (primarily L5), 6 clusters (primarily C2 and C4), diverse serotypes, and 61.95 % transposon-containing strains. The mcr-1 gene co-existed with 46 antibiotic resistance genes (ARGs) and 19 virulence factor genes (VFGs). Notably, 6 IncI2 plasmids carried the bla CTX-M , IS1380, and mcr-1 genes. MCRPEC from WWTPs harbored a greater number of ARGs (56.95 ± 5.99) but fewer VFGs (15.03 ± 6.40) compared to those from human-associated sources (LRF and IAW). ST1011, ST2705, IncHI2, and L7 were prevalent in WWTP-derived MCRPEC, whereas IncX4 and L3 were more common in human-derived MCRPEC. Genetic features such as ST101, ST48, IncI2, L4, L5, C2, and C4 were simultaneously present in strains from LRF, IAW, and WWTPs. Core genetic analyses also showed genetically similar MCRPEC strains across various geographic locations. The findings underscore the extensive dissemination, strong environmental adaptation, and clonal transmission of MCRPEC across diverse reservoirs, reinforcing the urgent need for coordinated multisectoral surveillance of human and environment interfaces to effectively mitigate further transmission., (Copyright © 2024. Published by Elsevier B.V.)

Wastewater treatment plants (WWTP) are recognized as major sources of microplastic (MP) particles in terrestrial environments, particularly in agricultural soils through biosolids application. While many reviews have focused on the distribution, detection, and mitigation of MPs in wastewater effluent to limit their discharge into oceans, our understanding of methods to mitigate biosolid contamination remains limited. This review focuses on methods for mitigating MPs contamination in biosolids at various intervention points, including sources, WWTP including the primary and secondary treatment stages where sludge is generated, and post-contamination. These methods are categorized as physical, physicochemical, and biological approaches, and their advantages and limitations are discussed. For instance, physicochemical methods, especially froth flotation, are cost-effective but are hindered by contaminants and reagents. Physical methods like microfibre filtration devices (MFD) are safe but their efficiency depends on the filter pore size and design. Biological methods, particularly microbial degradation, are limited by the varying efficiencies of microorganisms in breaking down MPs and the extended time required for their effective degradation. Other physical methods including dissolved air flotation, and ultrasonication already exist in WWTPs but may require retrofitting or optimization to enhance MP removal from biosolids. As each method inherently has limitations, the key to achieving MP-free biosolids, and thus preventing their release into agricultural soil, lies in integrating these methods through multi-coupling strategies., (Copyright © 2024. Published by Elsevier B.V.)

As antimicrobial resistance continues to pose a significant threat to global health, this study provided a focused examination of the prevalence and behavior of key antibiotic resistance genes in aquatic environments. We investigated the quantitative distribution of intI1, sul1, bla TEM , bla NDM , bla VIM , mcr-1, tetQ, and crAssphage within wastewater influents (n = 12), effluents (n = 12) and river water samples (n = 12), from three municipal wastewater treatment plants and three river locations in an urbanized watershed in Central Thailand over dry and wet seasons. The qPCR method demonstrated that intI1, sul1, bla TEM , and tetQ were the most abundant in all samples (2.71-7.89 mean log 10 copies/100 mL), with all genes exhibiting consistently uniform levels across diverse locations, suggesting the potential for any site to act as a monitoring sentinel. Although there is a significant reduction of ARG concentrations by WWTPs (0.62 - >4.05 LRV), the persistence of these genes in effluents points to the limited effectiveness of existing treatment methodologies. Temporal data indicated stable ARG concentrations over time, but tetQ levels rose during the wet season, in alignment with the monsoonal climate in Thailand. Additionally, we identified crAssphage, a marker of human sewage contamination, exhibited strong correlations with the more abundant ARGs (rho 0.65 - 0.81), implying that human waste contributes significantly to the environmental burden of ARGs. The results of this research highlight the widespread nature of ARGs in water systems and the need for improved treatment and sanitation strategies to mitigate the public health threat posed by antimicrobial resistance., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

This study investigated the occurrence and fate of 19 biocides in 8 wastewater treatment plants and receiving aquatic environments (both freshwater and estuarine systems) in Thailand. The predominant compound in wastewater and surface water was methylparaben with the maximum concentration of 15.2 μg/L detected in the receiving river, while in sludge and sediment was triclocarban with the maximum concentration of 8.47 μg/g in sludge. Triclosan was the main contaminants in the fish samples with the maximum concentration of 1.20 μg/g. Similar results of biocides were found in the estuarine system in Pattaya city, with the maximum concentration of 185 ng/L in sea water for methylparaben, and 242 ng/g in estuarine sediment for triclocarban. The aqueous removal rates for the biocides ranged from 15% to 95% in average. The back estimated-usage and total estimated emission of Ʃ19 biocides in Thailand was 279 and 202 tons/year, respectively. Preliminary ecological risk assessment showed that clotrimazole and triclosan could pose high risks to aquatic organisms in the receiving aquatic environments. Unlabelled Image • Biocides were widely detected at high levels in WWTPs and their receiving rivers. • Parabens were removed with high efficiency in WWTPs. • 9 biocides were detected in the collected fish. • Clotrimazole and triclosan showed high risks to aquatic organisms. [ABSTRACT FROM AUTHOR]

Due to the impact of methane, carbon dioxide and nitrous oxide on global warming, the quantity of these greenhouse gases (GHG) emissions from municipal wastewater treatment plants (WWTPs) has attracted more and more attention. Consequently, GHG emissions from the two popular treatment technologies: anaerobic/anoxic/oxic (AAO) process and sequencing batch reactor (SBR) should be properly identified and discussed toward the current situation in developing countries. Direct and indirect carbon dioxide (with and/or without including in Intergovernmental Panel on Climate Change (IPCC) report) are all discussed in this article. This literature study observed that a quantity of total carbon dioxide emissions from SBR (374 g/m3 of wastewater) was double that of AAO whilst 10% of these was direct carbon dioxide. Methane emitted from an SBR was 0.50 g/m3 wastewater while 0.18 g CH 4 /m3 wastewater was released from an AAO. The level of nitrous oxide from AAO and SBR accounted for 0.97 g/m3 wastewater and 4.20 g/m3 wastewater, respectively. Although these results were collected from different WWTPs and where influent was in various states, GHGs emitted from both biological units and other treatment units in various processes are significant. The results also revealed that aerated zone is the major contributing factor in a wastewater treatment plant to the large amount of GHG emissions. Unlabelled Image • Aerated zones significantly contribute to GHGEs in both AAO and SBR. • Higher emission was found in SBR than in AAO in terms of CO 2 , CH 4 and N 2 O. • To quantify direct emissions with low uncertainty is essential for GHG controlling. • GHGEs impact factors help in establishing the rational control strategies. [ABSTRACT FROM AUTHOR]

Abstract The emerged threat of microplastics (MPs) in aquatic ecosystems is posing a new challenges in environmental management, in particular the civil Wastewater Treatment Plants (WWTPs) which can act both as collectors of MPs from anthropic use and as a source to natural environments. In this study, MP fate was investigated in one of the biggest WWTPs of Northern Italy, built at the beginning of the 2000s and which serves a population equivalent of about 1,200,000, by evaluating their presence at the inlet (IN), the removal efficiency after the settler (SET) and at the outlet (OUT), and their transfer to sludge. Samples were collected in three days of a week and plastic debris was characterized in terms of shape, size and polymer composition using the Fourier Transform Infrared Microscope System (μFT-IR). The number of detected MPs was 2.5 ± 0.3 MPs/L in the IN, 0.9 ± 0.3 MPs/L after the SET and 0.4 ± 0.1 MPs/L in the OUT, indicating a total removal efficiency of 84%. However, considering that this WWTP treats about 400,000,000 L wastewaters/day, the potential release of MPs to the receiving aquatic system would be approximately 160,000,000 MPs/day, mainly polyesters (35%) and polyamide (17%). Furthermore, a great amount of MPs removed from wastewater was detected in the recycled activated sludge, with 113 ± 57 MPs/g sludge dry weight, corresponding to about 3,400,000,000 MPs deposited in the 30 tons of sludge daily produced by this WWTP. Given the possible re-use of WWTP sludge in fertilizers for agriculture, our results highlight that WWTPs could represent a potential source of MPs also to agroecosystems. Graphical abstract Unlabelled Image Highlights • Selected Wastewater Treatment Plant (WWTP) removes the 84% of microplastics (MPs). • 160,000,000 MPs were released daily by selected WWTP. • 3,400,000,000 MPs were deposited daily in 30 tons of sludge by selected WWTP. • WWTPs are a source of MPs in both aquatic and terrestrial environment. [ABSTRACT FROM AUTHOR]

Abstract The importance of noroviruses (NoVs) in the epidemiology of waterborne diseases has increased globally in the last decades. The present study aimed to monitor genogroup I and II noroviruses in different treatment stages of four wastewater treatment plants (WWTPs) in the metropolitan São Paulo. WWTPs consist of secondary (activated sludge) and tertiary treatments (coagulation, sand-anthracite filters, membrane bioreactor (MBR)/reverse osmosis (RO) and chlorination). Raw sewage (500 mL) and treated effluents (1 L) were concentrated by celite and reclaimed water (40 L) by hollow-fiber ultrafiltration system. Quantitative (qPCR) and nested PCR with nucleotide sequencing were used for quantification and molecular characterization. NoVs were widely distributed in raw wastewater samples (83.3%–100% NoV GI and 91.6%–100% NoV GII) and viral loads varied from 3.8 to 6.66 log 10 gc L−1 for NoV GI and 3.8 to 7.3 log 10 gc L−1 for NoV GII. Mean virus removal efficiencies obtained for activated sludge processes ranged from 0.3 to 0.8 log 10 for NoV GI and 0.4 to 1.4 log 10 for NoV GII. NoVs were not detected in the reuse water produced by MBR/RO system, while sand-anthracite filters resulted in a NoV GI and GII decay of 1.1–1.6 log 10 and 0.7–1.6 log 10 , respectively. A variety of genotypes (GI.2, GI.3a, GI.3b, GI.5, GII.1, GII.4 Sydney 2012, GII.5, GII.6, GII.17) was observed, with a predominance of GI.2 and GII.17 in the different genogroups. These results corroborate with recent data about the entry and dissemination of the emerging genotype GII.P17-GII.17 Kawasaki 2014 in the country, and may indicate a change in the epidemiological patterns of norovirus strains circulation in this region. This is the first large-scale study to evaluate burden and genotypes of noroviruses in WWTPs in Brazil, providing a rapid diagnosis of viruses circulating in the population. Graphical abstract Unlabelled Image Highlights • Noroviruses are widely disseminated in the municipal wastewaters of São Paulo city. • Higher viral loads were observed in winter season. • Activated sludge processes showed higher impact on NoV GII removal than NoV GI. • Results demonstrated the best performance of the MBR/RO systems in virus removal. • Prevalence of GII.17 indicates a shift in the epidemiology of NoV GII in the city. [ABSTRACT FROM AUTHOR]

Abstract Microplastics, as emerging contaminants in the global environment, have become a cause for concern for both academics and the public. The present understanding of microplastic pollution is primarily focused on marine environments, and less attention has been given to freshwater environments, in particular, to urban rivers. In this study, microplastics were sampled from surface water and sediments in 14 sites located in the lower course of the Pearl River. These sampling sites are located along Guangzhou of South China, with built-up areas being the dominant land use. The abundances of microplastics in surface water and sediments ranged from 379 to 7924 items·m−3 and 80 to 9597 items·kg−1, respectively. Polyethylene and polypropylene were the common types of microplastics, together accounting for 64.3% and 73.8% of surface water and sediment samples, respectively. Fibers were the dominant microplastic shapes in both water and sediment samples. The abundances of microplastics varied in surface water and sediments with each site, which might be affected by multiple factors. Our results indicated that wastewater treatment plants (WWTP) could reduce microplastics from municipal sewage which was finally discharged into the Pearl River along Guangzhou. Graphical abstract Unlabelled Image Highlights • Microplastics in the Pearl River along Guangzhou were investigated for the first time. • Fibers were detected in both surface water and sediment samples. • PE and PP were the dominant polymer types in surface water and sediments. • WWTP in Guangzhou could reduce microplastic pollution in the municipal sewage. [ABSTRACT FROM AUTHOR]

This study investigated the spatiotemporal distribution of 17 pharmaceuticals in wastewater treatment plants (WWTPs) from 17 provinces across China, and explored structural insights into their removal in full-scale wastewater treatment processes by quantum chemistry. Briefly, 10 pharmaceuticals were detected in above 85 % of samples, of which ibuprofen and sulfamethoxazole dominated with concentrations up to the μg/L level. Seasonally, concentrations of psychoactive drugs (PDs) were 1.3-2.6 times higher in summer than in other seasons. Spatially, higher average concentrations were detected in northern WWTPs, and regions with similar economic levels exhibited similar contamination patterns. Pharmaceutical removal in WWTPs ranged from 41.4 % (carbamazepine) to 87.2 % (sulfamethizole), with the secondary treatment segment, especially aerobic treatment units, maintaining an important position. Molecular structural mechanisms behind these removal performances were further revealed. Firstly, we demonstrated a significant association of pharmaceutical overall removal with electrophilicity index (ωcubic) as well as the lowest unoccupied molecular orbital energy (ELUMO). Highly electrophilic pharmaceuticals may persist in WWTPs and their sensitivity to electron exchange reactions accounted for the discrepant removal. In terms of treatment segments, pharmaceuticals with reaction sites masked in molecular structure, such as ibuprofen and venlafaxine, showed a propensity for tertiary treatment suitability. Furthermore, enzymes of aerobic units exhibited excellent docking affinity to pharmaceutical molecules with an average affinity of -7.2 kcal/mol, and hydrogen-bond interactions played an important factor in promoting biodegradation. Our results emphasize the necessity of assessing pharmaceutical contamination on a larger spatiotemporal scale. Moreover, the structural insights into removal phenomena offer scientific molecular-level justification for the design and optimization of pharmaceutical treatment technologies in WWTPs., (Copyright © 2023. Published by Elsevier B.V.)

In this work, the presence of 20 pharmaceuticals in wastewater from Colombia is investigated. Several widely consumed compounds have been detected in wastewater samples from different origins and geographical areas in Colombia. The studied pharmaceuticals included antibiotics, analgesics and anti-inflammatories, cholesterol lowering statin drugs, lipid regulators, and anti-depressants. The investigated samples were urban wastewater collected during one whole week before (influent) and after treatment (effluent) in the wastewater treatment plants (WWTPs) of Bogotá and Medellin. Raw wastewater from the Hospital of Tumaco and from the city of Florencia were also collected. Analyses performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed that most of the target analytes were present in all the wastewater samples. The highest concentrations (up to 50 μg/L) corresponded to acetaminophen, but several antibiotics, such as azithromycin, ciprofloxacin and norfloxacin, and antihypertensive drugs, such as losartan and valsartan, were commonly present in influent wastewater (IWW) at levels above 1 μg/L. Moreover, the treatment applied in WWTPs seemed to not efficiently remove the compounds under study, because most pharmaceuticals were also present in effluent wastewater (EWW) at concentrations close to those of the IWW. Special emphasis was made in this work on the quality of data reported, performing a detailed study of quality control (QC) samples. The analytical approach used –direct injection of 5-fold diluted samples without any additional treatment – is simpler and faster than the commonly applied solid phase extraction (SPE). The use of 12 isotope-labelled internal standards ensured the satisfactory correction of matrix effects for the corresponding analytes. For the remaining 8 compounds, no drastic matrix effects were observed, and only four compounds (cloxacillin, doxycycline, losartan, tetracycline) presented QC recoveries near or slightly below 60%, revealing ionization suppression, particularly in the IWW. Data on the occurrence of pharmaceuticals reported in this paper are the basis for current studies that aim to develop efficient systems for the degradation/removal of these compounds from the aquatic environment. [ABSTRACT FROM AUTHOR]

Pharmaceuticals (PhCs) are organic contaminants that have been detected in wastewater, surface water, and soils throughout the world. The presence of 10 commonly used PhCs in Spain (azithromycin, benzylpenicillin, citalopram, fluconazole, fluoxetine, ibuprofen, irbesartan, olanzapine, telmisartan, and venlafaxine) was analysed at four wastewater treatment plants, and the changes in their concentrations during treatment were assessed. Although certain some PhCs were degraded in the treated water, their presence in sewage sludge increased in all cases. The sewage sludge was composted using rice straw to degrade the PhCs, and the composting efficiency was modified by changes in the relative C/N ratio of the composting blend. Using a simple microbiological culture process for enrichment, 11 different strains of microorganisms that degraded specific PhCs were identified. Ibuprofen and azithromycin were metabolized by one and four strains, respectively, and both PhCs were used as a carbon source; in addition, six strains used irbesartan as a nitrogen source. [ABSTRACT FROM AUTHOR]

Shewanella species have a diverse respiratory ability and wide distribution in environments and play an important role in bioremediation and the biogeochemical cycles of elements. Primers with more accuracy and broader coverage are required with consideration of the increasing number of Shewanella species and evaluation of their roles in various environments. In this work, a new primer set of 640F/815R was developed to quantify the abundance of Shewanella species in natural and engineered environments. In silico tools for primer evaluation, quantitative polymerase chain reaction (qPCR) and clone library results showed that 640F/815R had a higher specificity and coverage than the previous primers in quantitative analysis of Shewanella . Another newly developed primer pair of 211F/815cR was also adopted to analyze the Shewanella diversity and demonstrated to be the best candidate in terms of specificity and coverage. We detected more Shewanella -related species in freshwater environments and found them to be substantially different from those in marine environments. Abundance and diversity of Shewanella species in wastewater treatment plants were largely affected by the process and operating conditions. Overall, this study suggests that investigations of abundance and diversity of Shewanella in various environments are of great importance to evaluate their ecophysiology and potential ecological roles. [ABSTRACT FROM AUTHOR]

Local adaptation is of fundamental importance for populations to cope with fast, human-mediated environmental changes. In the past, analyses of local adaptation were restricted to few model species. Nowadays, due to the increased affordability of high-throughput sequencing, local adaptation can be studied much easier by searching for patterns of positive selection using genomic data. In the present study, we analysed effects of wastewater treatment plant and ore mining effluents on stream invertebrate populations. The two different anthropogenic stressors have impacted on stream ecosystems over different time scales and with different potencies. As target organisms we selected two macroinvertebrate species with different life histories and dispersal capacities: the caddisfly Glossosoma conformis and the flatworm Dugesia gonocephala . We applied a genome-wide genetic marker technique, termed ddRAD (double digest restriction site associated DNA) sequencing, to identify local adaptation. Ten and 18% of all loci were identified as candidate loci for local adaptation in D . gonocephala and G . conformis , respectively. However, after stringent re-evaluation of the genomic data, strong evidence for local adaptation remained only for one population of the flatworm D . gonocephala affected by high copper concentration from ore mining. One of the corresponding candidate loci is arnt , a gene associated with the response to xenobiotics and potentially involved in metal detoxification. Our results support the hypotheses that local adaptation is more likely to play a central role in environments impacted by a stronger stressor for a longer time and that it is more likely to occur in species with lower migration rates. However, these findings have to be interpreted cautiously, as several confounding factors may have limited the possibility to detect local adaptation. Our study highlights how genomic tools can be used to study the adaptability and thus resistance of natural populations to changing environments and we discuss prospects and limitations of the methods. [ABSTRACT FROM AUTHOR]

The occurrence of pharmaceutical and steroid compounds in groundwater due to wastewater reuse has been reported and is of concern in tropical islands which primarily rely on groundwater. The objective of this study was to investigate the occurrence and removal of 43 pharmaceutical and steroid compounds detected in wastewater at four different wastewater treatment plants (WWTPs) in Hawai‘i and to understand their environmental behavior through tropical soils as the treated effluents are used in landscapes for irrigation. Eight soil sampling locations, collected at three different depths, representing the most common soil types in Hawai‘i and four WWTPs located across the major Hawaiian Islands were used. Disturbed soil samples were used to conduct the soil sorption and degradation studies and to estimate the leaching risk associated to the identified compounds. Quantification of selected compounds was conducted using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Among the investigated compounds, only ten were detected in the treated effluents at concentrations ranging from 0.004 to 0.900 μg L −1 . Caffeine (64 μg L −1 ) and ibuprofen (96.5 μg L −1 ) showed the highest concentration in raw samples, while diphenhydramine (0.9 μg L −1 ) showed the highest concentration in treated effluent samples. Sulfamethoxazole showed the lowest removal (0–75%). Several pharmaceuticals showed consistently higher sorption capacity and longer persistency compared with steroids regardless of soil types and depths. Poamoho (Oxisol soil) and Waimānalo (Mollisol soil) showed the highest sorption capacity, while Waimea (Entisol soil) showed the lowest sorption capacity. Soil physico-chemical properties (i.e., clay content, level of organic carbon, and presence of metal oxide) and soil depth highly impacted the sorption behavior of the selected pharmaceutical compounds. In particular, the sorption capacity decreased with soil depth due to the higher level of organic carbon present in the first 30 cm compared with the deeper depths (60–90 cm). [ABSTRACT FROM AUTHOR]

The present work describes the first known study to date on the occurrence of pharmaceuticals in surface water and wastewater of Cuernavaca, the capital of the state of Morelos (México). Selected pharmaceuticals (a total of 35) were extracted from the collected water samples with a generic solid phase extraction (SPE) protocol and determined in the sample extracts by means of high-performance liquid chromatography coupled to electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS). A screening level risk assessment combining the measured environmental concentrations (MECs) with dose-response data based on predicted no-effect concentrations (PNECs) was also applied to estimate Hazard Quotients (HQs) for the pharmaceuticals detected in the investigated area. A total of twelve pharmaceuticals were found in the water samples analyzed, with detection frequencies above 78% and in most cases of 100%. Overall, the most abundant pharmaceuticals in surface water were the analgesic and anti-inflammatory drugs naproxen (732–4880 ng/L), acetaminophen (354–4460 ng/L), and diclofenac (258–1398 ng/L), and the lipid regulator bezafibrate (286–2100 ng/L). On the contrary, other compounds like the β-blocker atenolol and the psychiatric drug carbamazepine were found at only a few ng or tens of ng per liter in the Apatlaco River. Despite the fact that some of the most abundant compounds showed good removal (> 97%) during wastewater treatment, concentrations downstream the WWTP were only slightly lower than upstream. This indicates the existence of additional inputs of untreated wastewater into the river. Based on the obtained HQ-values, the concentrations of ibuprofen, sulfamethoxazole, diclofenac and naproxen present in the river could pose a high toxicity risk for the aquatic ecosystem. These findings highlight these pharmaceuticals as relevant organic contaminants in the area of study and the need to further monitor them in order to adopt appropriate measures to safeguard the ecosystem, and eventually human health. [ABSTRACT FROM AUTHOR]

Contamination of receiving waters with pharmaceutical compounds is of pressing concern. This constitutes the first study to report on the development of a semi-quantitative risk assessment (RA) model for evaluating the environmental threat posed by three EU watch list pharmaceutical compounds namely, diclofenac, 17-beta-estradiol and 17-alpha-ethinylestradiol, to aquatic ecosystems using Irish data as a case study. This RA model adopts the Irish Environmental Protection Agency Source-Pathway-Receptor concept to define relevant parameters for calculating low, medium or high risk score for each agglomeration of wastewater treatment plant (WWTP), which include catchment, treatments, operational and management factors. This RA model may potentially be used on a national scale to (i) identify WWTPs that pose a particular risk as regards releasing disproportionally high levels of these pharmaceutical compounds, and (ii) help identify priority locations for introducing or upgrading control measures (e.g. tertiary treatment, source reduction). To assess risks for these substances of emerging concern, the model was applied to 16 urban WWTPs located in different regions in Ireland that were scored for the three different compounds and ranked as low, medium or high risk. As a validation proxy, this case study used limited monitoring data recorded at some these plants receiving waters. It is envisaged that this semi-quantitative RA approach may aid other EU countries investigate and screen for potential risks where limited measured or predicted environmental pollutant concentrations and/or hydrological data are available. This model is semi-quantitative, as other factors such as influence of climate change and drug usage or prescription data will need to be considered in a future point for estimating and predicting risks. [ABSTRACT FROM AUTHOR]

We quantified pesticide contamination and its ecological impact up- and downstream of seven wastewater treatment plants (WWTPs) in rural and suburban areas of central Germany. During two sampling campaigns, time-weighted average pesticide concentrations ( c TWA ) were obtained using Chemcatcher® passive samplers; pesticide peak concentrations were quantified with event-driven samplers. At downstream sites, receiving waters were additionally grab sampled for five selected pharmaceuticals. Ecological effects on macroinvertebrate structure and ecosystem function were assessed using the biological indicator system SPEAR pesticides (SPEcies At Risk) and leaf litter breakdown rates, respectively. WWTP effluents substantially increased insecticide and fungicide concentrations in receiving waters; in many cases, treated wastewater was the exclusive source for the neonicotinoid insecticides acetamiprid and imidacloprid in the investigated streams. During the ten weeks of the investigation, five out of the seven WWTPs increased in-stream pesticide toxicity by a factor of three. As a consequence, at downstream sites, SPEAR values and leaf litter degradation rates were reduced by 40% and 53%, respectively. The reduced leaf litter breakdown was related to changes in the macroinvertebrate communities described by SPEAR pesticides and not to altered microbial activity. Neonicotinoids showed the highest ecological relevance for the composition of invertebrate communities, occasionally exceeding the Regulatory Acceptable Concentrations (RACs). In general, considerable ecological effects of insecticides were observed above and below regulatory thresholds. Fungicides, herbicides and pharmaceuticals contributed only marginally to acute toxicity. We conclude that pesticide retention of WWTPs needs to be improved. [ABSTRACT FROM AUTHOR]

For the first time the occurrence of 26 nitrogen heterocyclic polyaromatic hydrocarbons (N-HETs) and the antiepileptic drug carbamazepine (CBZ) as a marker for anthropogenic influence was determined in an entire river system and its influents. Besides the investigation of diurnal and annual variations in concentrations, dilution and load calculations, the aims were to facilitate transferability to other rivers by identifying sources of the different substances. To create a sufficient database over 180 aqueous samples from the River Fuhse (Lower Saxony, Germany), its catchment area, effluents of municipal and industrial wastewater treatment plants (WWTPs) and rainwater were analyzed. Typical substances found in background water samples and rain samples were quinoline and isoquinoline, whereas 1-/3-methylisoquinoline were traced back to an industrial WWTP. Due to similar concentration levels in the effluents of municipal WWTPs, their impact on the river correlated with their nominal loads. In municipal WWTP effluents CBZ (c median = 1693 ng L − 1 ), 2-methylquinoline (c median = 64 ng L − 1 ), and acridine (c median = 62 ng L − 1 ) prevailed. Although the occurrence of N-HETs at contaminated sites is a widely discussed scientific topic, this study showed that the investigated site was a source with only small volumetric contribution to N-HET concentrations in the adjacent river. In total the River Fuhse discharges 20 kg a − 1 N-HETs and 21 kg a − 1 CBZ into the receiving river. [ABSTRACT FROM AUTHOR]

This review presents the state-of-the-art sludge reduction technologies applied in both wastewater and sludge treatment lines. They include chemical, mechanical, thermal, electrical treatment, addition of chemical un-coupler, and predation of protozoa/metazoa in wastewater treatment line, and physical, chemical and biological pretreatment in sludge treatment line. Emphasis was put on their effect on sludge reduction performance, with 10% sludge reduction to zero sludge production in wastewater treatment line and enhanced TS (total solids) or volatile solids removal of 5–40% in sludge treatment line. Free nitrous acid (FNA) technology seems good in wastewater treatment line but it is only under the lab-scale trial. In sludge treatment line, thermal, ultrasonic (< 4400 kJ/kg TS), FNA pretreatment and temperature-phased anaerobic digestion (TPAD) are promising if pathogen inactivation is not a concern. However, thermal pretreatment and TPAD are superior to other pretreatment technologies when pathogen inactivation is required. The new wastewater treatment processes including SANI®, high-rate activated sludge coupled autotrophic nitrogen removal and anaerobic membrane bioreactor coupled autotrophic nitrogen removal also have a great potential to reduce sludge production. In the future, an effort should be put on the effect of sludge reduction technologies on the removal of organic micropollutants and heavy metals. [ABSTRACT FROM AUTHOR]

Municipal wastewater treatment plants (WWTPs) are an important source of pharmaceuticals released into the environment. Understanding how various pharmaceuticals are distributed and handled in WWTPs is a prerequisite to optimize their abatement. Here we investigated the spatial distribution and removal efficiencies pharmaceuticals in China's WWTPs. A total of 35 pharmaceuticals in wastewater samples from 12 WWTPs at different cities of China were analyzed. Among these detected pharmaceuticals, caffeine showed the highest concentration (up to 1775.98 ng L − 1 ) in the WWTP influent. In addition, there were significant regional differences in pharmaceutical distribution with higher influent concentrations of total pharmaceuticals detected in WWTPs in the northern cities than the southern ones. The state-of-the-art treatment processes were generally inefficient in removing pharmaceuticals. Only 14.3% of pharmaceuticals were removed effectively (mean removal efficiency > 70%), while 51.4% had a removal rate of below 30%. The anaerobic/anoxic/oxic (AAO)-membrane bioreactor (MBR) integrated process and sequencing batch reactor (SBR) showed better performance than the AAO and oxidation ditch (OD) processes. Ofloxacin, erythromycin-H 2 O, clarithromycin, roxithromycin and sulfamethoxazole in WWTP effluents exhibited a high or medium ecological risk and deserved special attention. [ABSTRACT FROM AUTHOR]