Investigation of PPCPs in wastewater treatment plants in Greece: occurrence, removal and environmental risk assessment

Use of micropollutant indicator ratios to characterize wastewater treatment plant efficiency and to identify wastewater impact on groundwater

Contamination by wastewater has been traditionally assessed by measuring faecal coliforms, such as E. coli and entereococci. However, using micropollutants to track wastewater input is gaining interest. In this study, we identified nine micropollutant indicators that could be used to characterize water quality and wastewater treatment efficiency in pond-based wastewater treatment plants (WWTPs) of varying configuration. Of 232 micropollutants tested, nine micropollutants were detected in treated wastewater at concentrations and frequencies suitable to be considered as indicators for treated wastewater. The nine indicators were then classified as stable (carbamazepine, sucralose, benzotriazole, 4+5-methylbenzotriazole), labile (atorvastatin, naproxen, galaxolide) or intermediate/uncertain (gemfibrozil, tris(chloropropyl)phosphate isomers) based on observed removals in the pond-based WWTPs and correlations between micropollutant and dissolved organic carbon removal. The utility of the selected indicators was evaluated by assessing the wastewater quality in different stages of wastewater treatment in three pond-based WWTPs, as well as selected groundwater bores near one WWTP, where treated wastewater was used to irrigate a nearby golf course. Ratios of labile to stable indicators provided insight into the treatment efficiency of different facultative and maturation ponds and highlighted the seasonal variability in treatment efficiency for some pond-based WWTPs. Additionally, indicator ratios of labile to stable indicators identified potential unintended release of untreated wastewater to groundwater, even with the presence of micropollutants in other groundwater bores related to approved reuse of treated wastewater.

Comprehensive analysis of a widely pharmaceutical, furosemide, and its degradation products in aquatic systems: Occurrence, fate, and ecotoxicity

Many pharmaceutical compounds end up in the environment due to incomplete removal by wastewater treatment plants (WWTPs). Some compounds are sometimes present in significant concentrations and therefore represent a risk to the aquatic environment. Furosemide is one of the most widely used drugs in the world. Considered as an essential drug by the World Health Organization, this powerful loop diuretic is used extensively to treat hypertension, heart and kidney failure and many other purposes. However, this important consumption also results in a significant release of furosemide in wastewater and in the receiving environment where concentrations of a few hundred ng/L to several thousand have been found in the literature, making furosemide a compound of great concern. Also, during its transport in wastewater systems and WWTPs, furosemide can be degraded by various processes resulting in the production of more than 74 by-products. Furosemide may therefore present a significant risk to ecosystem health due not only to its direct cytotoxic, genotoxic and hepatotoxic effects in animals, but also indirectly through its transformation products, which are poorly characterized. Many articles classify furosemide as a priority pollutant according to its occurrence in the environment, its persistence, its elimination by WWTPs, its toxicity and ecotoxicity. Here, we present a state-of-the-art review of this emerging pollutant of interest, tracking it, from its consumption to its fate in the aquatic environment. Discussion points include the occurrence of furosemide in various matrices, the efficiency of many processes for the degradation of furosemide, the subsequent production of degradation products following these treatments, as well as their toxicity.

Unravelling psychoactive substances and their metabolites and transformation products: High-Resolution Mass Spectrometry approaches for comprehensive target and suspect screening in wastewater

Untangling the consumption rates of psychiatric drugs and their metabolites/ transformation products-(TPs) through wastewater gains attention lately. However, the potential environmental impact caused by their release remains ambiguous. As it follows, the monitoring of this class of pharmaceuticals as well as the evaluation of their potential toxicity is a matter of high concern. In the light of the above, here, wastewater samples, were collected in a 1-year and a half sampling campaign (2020-2021) and were further subjected to solid phase extraction. A Q Exactive Focus Orbitrap mass analyzer was employed for the analysis of the samples. For the data curation, except of the monitoring of targets, a comprehensive suspect screening workflow was developed and slightly optimized based on a lab made HRMS database for the investigation of legally or illegally prescribed psychiatric drugs and their relevant metabolites/TPs in influents and effluents. Carbamazepine and amisulpride were quantified at the highest mean concentrations 243 and 225 ng/L respectively, in influents. In effluents, the highest mean concentrations were calculated for carbamazepine (180 ng/L) and venlafaxine (117 ng/L). The implementation of suspect screening approach enhanced the comprehensiveness of analysis by detecting 29 compounds not included in the target list. O-Desmethylvenlafaxine was the predominant metabolite in influents presenting a mean concentration equal to 87 ng/L while the same pattern was also noticed in effluents where the mean concentration was up to 91 ng/L. From the group of suspect compounds for which no analytical standards were available, the predominant compounds with detection frequency 100 % were norephedrine and codeine in influents while in effluents, oxazepam was detected in 81 % of the analyzed samples. Finally, in silico and mathematical tools were employed for the assessment of the risk posed to environmental systems. Most of the detected compounds present high risk in all trophic levels.

Unveiling combined ecotoxicity: Interactions and impacts of engineered nanoparticles and PPCPs

Emerging contaminants such as engineered nanoparticles (ENPs), pharmaceuticals and personal care products (PPCPs) are of great concern because of their wide distribution and incomplete removal in conventional wastewater and soil treatment processes. The production and usage of ENPs and PPCPs inevitably result in their coexistence in different environmental media, thus posing various risks to organisms in aquatic and terrestrial ecosystems. However, the existing literature on the physicochemical interactions between ENPs and PPCPs and their effects on organisms is rather limited. Therefore, this paper summarized the ecotoxicity of combined ENPs and PPCPs by discussing: (1) the interactions between ENPs and PPCPs, including processes such as aggregation, adsorption, transformation, and desorption, considering the influence of environmental factors like pH, ionic strength, dissolved organic matter, and temperature; (2) the effects of these interactions on bioaccumulation, bioavailability and biotoxicity in organisms at different trophic levels; (3) the impacted of ENPs and PPCPs on cellular-level biological process. This review elucidated the potential ecological hazards associated with the interaction of ENPs and PPCPs, and serves as a foundation for future investigations into the ecotoxicity and mode of action of ENPs, PPCPs, and their co-occurring metabolites.

Toxic effects of triclosan in aquatic organisms: A review focusing on single and combined exposure of environmental conditions and pollutants

Triclosan (TCS) is an antibacterial agent commonly used in personal care products. Due to its widespread use and improper disposal, it is also a pervasive contaminant, particularly in aquatic environments. When released into water bodies, TCS can induce deleterious effects on developmental and physiological aspects of aquatic organisms and also interact with environmental stressors such as weather, metals, pharmaceuticals, and microplastics. Multiple studies have described the adverse effects of TCS on aquatic organisms, but few have reported on the interactions between TCS and other environmental conditions and pollutants. Because aquatic environments include a mix of contaminants and natural factors can correlate with contaminants, it is important to understand the toxicological outcomes of combinations of substances. Due to its lipophilic characteristics, TCS can interact with a wide range of substances and environmental stressors in aquatic environments. Here, we identify a need for caution when using TCS by describing not only the effects of exposure to TCS alone on aquatic organisms but also how toxicity changes when it acts in combination with multiple environmental stressors.

Occurrence of Pharmaceutical Micropollutants in Lake Nahuel Huapi, Argentine Patagonia

Tourism is one of the most important activities for the economy of Nor Patagonia Argentina. In Bariloche City, located on the shores of Lake Nahuel Huapi, both the permanent and the temporary populations have increased significantly in recent decades, and this has not necessarily been accompanied by an improvement in sewage networks. Emerging micropollutants such as pharmaceutical compounds reach aquatic systems directly, in the absence of a domestic sewage network, or through effluents from wastewater treatment plants (WWTP), which do not efficiently remove these substances and represent a major threat to the environment. Therefore, the objective of our study was to monitor the presence of pharmaceutical compounds discharged both through wastewater effluents and diffusely from housing developments into Lake Nahuel Huapi. The results obtained demonstrate the presence of pharmaceuticals in Lake Nahuel Huapi with concentrations ranging from not detectable (ND) to 110.6 ng L-1 (caffeine). The highest pharmaceutical concentration recorded in WWTP influent corresponded to caffeine (41728 ng L-1), and the lowest concentration was paracetamol (18.8 ng L-1). The removal efficiency of pharmaceuticals in the WWTP was calculated, and ranged from 0% for carbamazepine to 66% for ciprofloxacin. This antibiotic showed the lowest % of attenuation (73%) in Lake Nahuel Huapi. These results on the occurrence of a wide variety of pharmaceuticals are the first generated in Patagonia, representing a regional baseline for this type of micropollutant and valuable information for the subsequent design of removal strategies for emerging pharmaceutical pollutants in surface water. Environ Toxicol Chem 2024;00:1-11. © 2024 SETAC.

Enhanced properties of a positive-charged nanofiltration membrane containing quaternarized chitosan through second interfacial polymerization for the removal of salts and pharmaceuticals

Nanofiltration (NF) membrane technology has been widely used in the removal of salts and trace organic pollutants, such as pharmaceuticals and personal care products (PPCPs), due to its superiority. A positive-charged composite NF membrane with an active skin layer was prepared by polyethyleneimine (PEI), trimethyl benzene chloride, and quaternate chitosan (HTCC) through second interfacial polymerization on the polyethersulfone ultrafiltration membrane. The physicochemical properties of the nanocomposite membrane were investigated using surface morphology, hydrophilicity, surface charge, and molecular weight cut-off (MWCO). The influence of the concentration and reaction time of PEI and HTCC was documented. The optimized membrane had a MWCO of about 481 Da and possessed a pure water permeability of 25.37 L·m-2·h-1·MPa-1. The results also exhibited salt rejection ability as MgCl2 > CaCl2 > MgSO4 > Na2SO4 > NaCl > KCl, showing a positive charge on the fabricated membrane. In addition, the membrane had higher rejection to atenolol, carbamazepine, amlodipine, and ibuprofen at 89.46, 86.02, 90.12, and 77.21%, respectively. Moreover, the anti-fouling performance and stability of the NF membrane were also improved.

Determination of caffeine in treated wastewater discharged in the Nile River with emphasis on the effect of zinc and physicochemical factors

The present study aimed to investigate the occurrence of caffeine residues in the Nile River according to drainage of treated wastewater at Assiut, Egypt, and the effects of physicochemical parameters and zinc on its concentration. Four different sites were selected to perform the study: S, wastewater treatment plant (WWTP) canal (source site); J, a junction site between WWTP canal and the Nile; R, a reference site in the Nile before J site; and A, a site located after J site in the Nile. Water and sediment samples were collected in Summer 2022 and Winter 2023. Caffeine and Zn concentrations and physicochemical parameters were measured in the collected samples. The caffeine concentrations in water samples ranged from 5.73 to 53.85 μg L-1 at S in winter and summer, respectively, while those in sediment ranged from 0.14 mg kg-1 at R in winter to 1.54 mg kg-1 at S in summer. Caffeine and Zn concentrations were higher in summer samples. The Water Quality Index (WQI) of the collected samples recorded the lowest values in winter season at S and J sites. The study found that caffeine and zinc concentrations are positively correlated with water temperature and conductivity, while negatively correlated with pH. The association between caffeine and Zn highlights the environmental impact of heavy metals and pharmaceutical residues, and stresses the need for future research on these interactions.

Exploring patterns of antibiotics during and after COVID-19 pandemic in wastewaters of northern Greece: Potential adverse effects on aquatic environment

Antibiotics, recognized as Emerging Contaminants (ECs), have raised concerns due to their pervasive presence in wastewater treatment plants (WWTPs) and subsequent release into aquatic environments, posing potential ecological risks and contributing to the development of antibiotic-resistant genes. The COVID-19 pandemic prompted an unprecedented surge in antibiotic consumption, necessitating a comprehensive assessment of its impact on antibiotic levels in wastewater. In this light, a four-year monitoring study (2020-2023) was conducted in a WWTP located in the Northern Greece (Thessaloniki), employing High-Resolution Mass Spectrometry (HRMS) technology to monitor twenty antibiotics, during distinct phases pre-, during, and post-COVID-19. Our findings revealed that macrolides and fluoroquinolones were among the most often detected categories during the sampling period. Among the compounds detected, azithromycin and clarithromycin showed the most significant increases during the pandemic, doubling their average concentrations. This establishes a clear correlation between the rise in their concentrations and the incidence of COVID-19 cases. A general downward trend after 2021 was attributed to the new restrictions posed in Greece during this year, regarding the liberal prescription of antibiotics. Seasonal variation revealed a minute augmentation of antibiotics' use during the months that infections are increased. Additionally, the study highlights the ecological risks associated with elevated antibiotic presence and emphasizes the need for continued monitoring and regulatory measures to mitigate potential ecological repercussions. These findings contribute to our understanding of the complex interplay between antibiotic consumption, environmental presence, and the COVID-19 pandemic's impact on antibiotic pollution in WWTPs.

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.

Ecotoxicological and human health risk assessment of triclosan antibacterial agent from municipal wastewater treatment plants

In this study, the occurrence and environmental risks related to triclosan (TCS) in the two wastewater treatment plants (WWTPs) were investigated in Isfahan, Iran. Influent and effluent samples were collected and analyzed by dispersive liquid-liquid microextraction (DLLME)-GC-MS method with derivatization. Moreover, the risk of TCS exposure was conducted for aquatic organisms (algae, crustaceans, and fishes) and humans (males and females). TCS mean concentrations in influent and effluent of WWTPs were in the range of 3.70-52.99 and 0.83-1.09 μg/L, respectively. There were also no differences in the quantity of TCS and physicochemical parameters among the two WWTPs. The mean risk quotient (RQ) for TCS was higher than 1 (in algae) with dilution factors (DFs) equal to 1 in WWTP1. Moreover, the RQ value was higher than 1 for humans based on the reference dose of MDH (RFDMDH) in WWTP1. Furthermore, TCS concentration in wastewater effluent was the influential factor in varying the risk of TCS exposure. The results of the present study showed the risk of TCS exposure from the discharge of effluent of WWTP1 was higher than WWTP2. Moreover, the results of this study may be suitable for promoting WWTP processes to completely remove micropollutants.

Influence of leachate microenvironment on the occurrence of phthalate esters in landfills

Phthalate esters (PAEs) are added to various products as plasticizers. Plastic waste containing PAEs enters landfills as they age with use. However, the influence of microenvironmental changes on the occurrence of PAEs during landfill stabilization is still unknown. In this study, we evaluated the relationship between the physical and chemical properties of leachate, the structure of bacterial communities and the chemical structure of dissolved organic matter (DOM), and the occurrence of PAEs and the mechanism underlying their responses to changes. Landfill leachate in different stabilization states had high Cl- and NH4+ contents and its metal element (Cr, Pb, and Zn) contents generally decreased with the increase in landfill ages. Proteobacteria, Bacteroidetes, and Firmicutes were important phyla and had an average relative abundance of 68.63%. The lignin/carboxylate-rich alicyclic molecule structure was the main component of DOM (56%-64%). Of the 6-priority controlled PAEs in leachate, di-n-butyl phthalate was the most abundant (1046 μg L-1), while butyl phthalate was not detected. The results showed that pH, the relative abundance of Chloroflexi, and the value of SUVA254 can directly influence the occurrence of PAEs in leachate. The positive and negative effects vary depending on the PAE content and molecular weight. DBP and DEHP have higher environmental risks in the aquatic system. These results are intended to provide a scientific basis for the evolutionary characterization of the microenvironment in complex environmental systems and the control of novel contaminants, such as PAEs.

Composting post-anaerobic digestion for emerging contaminant biodegradation: Impacts of operating conditions

Sustainable manure management technologies are needed, and combining anaerobic digestion (AD) for energy generation and aerobic composting (AC) to stabilize digestate and remove emerging contaminants (ECs), including veterinary pharmaceuticals and steroid hormones, is promising. This study identified post-AD, AC operating conditions that maximized degradation of study ECs, expected to be present in cattle manure digested using treated municipal wastewater as the water source. Study ECs included sulfamethoxazole (SMX), chlortetracycline (CTC), oxytetracycline (OTC), estrone (E1), and naproxen (NPX). Composting conditions were simulated in bench-scale reactors, with microorganisms from digestate produced in an AD system (25L scale), by varying temperatures, pH, and carbon source compositions (representing food waste/manure co-digestion with different residence times). Results indicate maximum SMX biodegradation occurred at 35°C, pH 7, and with high levels of easily degradable carbon (≥99%, 99%, and 98%), and maximum E1 biodegradation occurred at 35°C, and with low levels of easily degradable carbon (≥97% and 99%). Abiotic degradation was responsible for the nearly complete removal of tetracyclines under all conditions and for partial degradation of NPX (between 20% and 48%). Microorganisms originating from the AD system putatively capable of SMX and E1 biodegradation, or of contributing to biodegradation during the AC phase, were identified, including phylotypes previously shown to biodegrade SMX (Brevundimonas and Alcaligenes).

Occurrence and prevalence of antibiotics in wastewater treatment plants and effluent receiving rivers in South Africa using UHPLC-MS determination

The increased usage of antibiotics over the recent years has led to an increased interest in monitoring their presence in wastewater all over the world. In this study the occurrence of sixteen (16) selected antibiotics (amoxicillin, ampicillin, azithromycin, ciprofloxacin, doxycycline, erythromycin, gentamicin, metronidazole, norfloxacin, ofloxacin, penicillin, sulfamethoxazole, sulfapyridine, sulfamethizole, tetracycline and trimethoprim) were determined in two wastewater treatment plants and two effluent receiving rivers in Northern part of Pretoria, South Africa. Targeted screening and identification of antibiotics was done using ultra high-performance liquid chromatography coupled with mass spectrometry after sample clean-up and pre-concentration using solid phase extraction. The concentrations of the targeted antibiotics detected in influent samples ranged between 0.78 and 96.8 ng mL-1 and those in effluent were between 0.12 and 9.89 ng mL-1. The highest recorded concentrations in all samples were those of doxycycline (30.9-120 ng mL-1) and sulfamethoxazole (2.52-96.8 ng mL-1) in effluent and influent samples, respectively. The concentrations of antibiotics in the rivers receiving effluents were between 0.03 and 72.8 ng mL-1 in upstream samples and 0.008-76.8 ng mL-1 in downstream samples, indicating that there is other source of contaminate to these rivers other than the treatment plants. Risk assessment using the hazard quotients ranged between 0.24 and 889 indicating that the presence of these antibiotics and antibiotic mixtures posed higher ecological risks to aquatic organisms. From the study, it could be concluded that wastewater treatment plants were releasing antibiotics to the environment and posing a risk to the aquatic ecosystem and public health. Therefore, there is a need to research into developing more efficient conventional wastewater treatment technologies that can completely remove antibiotics from wastewater.

Assessment of selected pharmaceuticals in Riyadh wastewater treatment plants, Saudi Arabia: Mass loadings, seasonal variations, removal efficiency and environmental risk

Despite increasing interest in pharmaceutical emissions worldwide, studies of environmental contamination with pharmaceuticals arising from wastewater discharges in Saudi Arabia are scarce. Therefore, this study examined occurrence, mass loads and removal efficiency for 15 pharmaceuticals and one metabolite (oxypurinol) from different therapeutic classes in three wastewater treatment plants (WWTPs), in Riyadh city in Saudi Arabia. A total of 144 samples were collected from the influents and effluents between March 2018 and July 2019 and analyzed using Solid Phase Extraction followed by triple quadrupole LC-MS/MS. The average concentrations in the influents and effluents were generally higher than their corresponding concentrations found either in previous Saudi Arabian or global studies. The four most dominant compounds in the influent were acetaminophen, ciprofloxacin, caffeine, and diclofenac, with caffeine and acetaminophen having the highest concentrations ranging between 943 and 2282 μg/L. Metformin and ciprofloxacin were the most frequently detected compounds in the effluents at concentrations as high as 33.2 μg/L. Ciprofloxacin had the highest mass load in the effluents of all three WWTPs, ranging between 0.20 and 20.7 mg/day/1000 inhabitants for different WWTPs. The overall average removal efficiency was estimated high (≥80), with no significant different (p > 0.05) between the treatment technology applied. Acetaminophen and caffeine were almost completely eliminated in all three WWTPs. The samples collected in the cold season generally had higher levels of detected compounds than those from the warm seasons, particularly for NSAID and antibiotic compounds. The estimated environmental risk from pharmaceutical compounds in the studied effluents was mostly low, except for antibiotic compounds. Thus, antibiotics should be considered for future monitoring programmes of the aquatic environment in Saudi Arabia.

Emerging organic contaminants in the River Ganga and key tributaries in the middle Gangetic Plain, India: Characterization, distribution & controls

The presence and distribution of emerging organic contaminants (EOCs) in freshwater environments is a key issue in India and globally, particularly due to ecotoxicological and potential antimicrobial resistance concerns. Here we have investigated the composition and spatial distribution of EOCs in surface water along a ∼500 km segment of the iconic River Ganges (Ganga) and key tributaries in the middle Gangetic Plain of Northern India. Using a broad screening approach, in 11 surface water samples, we identified 51 EOCs, comprising of pharmaceuticals, agrochemicals, lifestyle and industrial chemicals. Whilst the majority of EOCs detected were a mixture of pharmaceuticals and agrochemicals, lifestyle chemicals (and particularly sucralose) occurred at the highest concentrations. Ten of the EOCs detected are priority compounds (e.g. sulfamethoxazole, diuron, atrazine, chlorpyrifos, perfluorooctane sulfonate (PFOS), perfluorobutane sulfonate, thiamethoxam, imidacloprid, clothianidin and diclofenac). In almost 50% of water samples, sulfamethoxazole concentrations exceeded predicted no-effect concentrations (PNECs) for ecological toxicity. A significant downstream reduction in EOCs was observed along the River Ganga between Varanasi (Uttar Pradesh) and Begusarai (Bihar), likely reflecting dilution effects associated with three major tributaries, all with considerably lower EOC concentrations than the main Ganga channel. Sorption and/or redox controls were observed for some compounds (e.g. clopidol), as well as a relatively high degree of mixing of EOCs within the river. We discuss the environmental relevance of the persistence of several parent compounds (notably atrazine, carbamazepine, metribuzin and fipronil) and associated transformation products. Associations between EOCs and other hydrochemical parameters including excitation emission matrix (EEM) fluorescence indicated positive, significant, and compound-specific correlations between EOCs and tryptophan-, fulvic- and humic-like fluorescence. This study expands the baseline characterization of EOCs in Indian surface water and contributes to an improved understanding of the potential sources and controls on EOC distribution in the River Ganga and other large river systems.

Screening of pharmaceutical and personal care products (PPCPs) along wastewater treatment system equipped with root zone treatment: A potential model for domestic waste leachate management

We present the use of root zone treatment (RZT) based system for the removal of pharmaceutical and personal care products (PPCPs) from domestic wastewater. The occurrence of more than a dozen PPCPs were detected in an academic institution wastewater treatment plant (WWTP) at three specific locations, i.e., influent, root treatment zone, and effluents. The comparisons of observed compounds detected at various stages of WWTP suggest that the presence of PPCPs, like homatropine, cytisine, carbenoxolone, 4,2',4',6'-tetrahydroxychalcone, norpromazine, norethynodrel, fexofenadine, indinavir, dextroamphetamine, 3-hydroxymorphinan, phytosphingosine, octadecanedioic acid, meradimate, 1-hexadecanoyl-sn-glycerol, and 1-hexadecylamine, are unusual than the usual reported PPCPs in the WWTPs. In general, carbamazepine, ibuprofen, acetaminophen, trimethoprim, sulfamethoxazole, caffeine, triclocarban, and triclosan are often reported in wastewater systems. The normalized abundances of PPCPs range between 0.037-0.012, 0.108-0.009, and 0.208-0.005 in main influent, root zone effluent, and main effluents, respectively, of the WWTP. In addition, the removal rates of PPCPs were observed from -200.75% to ∼100% at RZT phase in the plant. Interestingly, we observed several PPCPs at later stages of treatment which were not detected in the influent of the WWTP. This is probably owing to the presence of conjugated metabolites of various PPCPs present in the influent, which subsequently got deconjugated to reform the parent compounds during the biological wastewater treatment. In addition, we suspect the potential release of earlier absorbed PPCPs in the system, which were absent on that particular day of sampling but have been part of earlier influents. In essence, RZT-based WWTP was found to be effective in removing the PPCPs and other organic contaminants in the study but results in stress the need for further comprehensive research on RZT system to conclude the exact removal efficacy and fate of PPCPs during treatment in the system. As a current research gap, the study also recommended RZT to be appraised for PPCPs in-situ remediation from landfill leachates, an underestimated source of PPCPs intrusion in the environment.

Abnormal fluoride distribution, human health risk assessment, predicted no-effect concentration (PNEC) and environmental hazards in an Egyptian lake connected to the Mediterranean Sea

Fluoride can affect the metabolism and physiological functioning of humans and aquatic organisms like any hazardous substance when it exceeds its permissible limits and PNEC values. The fluoride content of the lake water and sediment samples collected from different locations was determined to assess its risks to humans and its ecological toxicity in Lake Burullus. Statistical analyses show that the proximity of the supplying drains had an impact on the fluoride content. Fluoride ingestion and skin contact in lake water and sediment during swimming for child, female and male were evaluated at 95, 90, and 50%. The values of hazard quotient (HQ) and total hazard quotient (THQ) for children, females and males were less than one, reflecting that exposure to fluoride through ingestion and skin-to-skin contact while swimming poses no risks to human health. PNEC values for fluoride in lake water and sediment were estimated using the equilibrium partitioning method (EPM). The ecological risk assessment of fluoride for acute and chronic toxicity was performed for the three trophic levels based on the PNEC, the half-maximal effective concentration (EC₅₀), the median lethal dose (LC₅₀), the no-observed effect concentration (NOEC), and the 5% lethal concentration (EC₀₅). The risk quotient (RQ), mixture risk characterization ratios (RCR_mix), relative contribution (RC), toxic unit (TU), and sum of toxic units (STU) were estimated. The acute and chronic RCR_mix(STU) and RCR_{mix(MEC/PNEC)} produced similar values for the three trophic levels in lake water and sediment, indicating that invertebrates are the most sensitive species to fluoride. These results of evaluating the environmental risks of fluoride in lake water and sediments reflected its significant impact on aquatic organisms living in the lake area in the long term.

Insight into pharmaceutical and personal care products removal using constructed wetlands: A comprehensive review

Pharmaceutical and personal care products (PPCPs) were regarded as emerging environmental pollutants due to their ubiquitous appearance and high environmental risks. The wastewater treatment plants (WWTPs) became the hub of PPCPs receiving major sources of PPCPs used by humans. Increasing concern has been focused on promoting cost-effective ways to eliminate PPCPs within WWTPs for blocking their route into the environment through effluent discharging. Among all advanced technologies, constructed wetlands (CWs) with a combination of plants, substrates, and microbes attracted attention due to their cost-effectiveness and easier maintenance during long-term operation. This study offers baseline data for risk control and future treatment by discussing the extent and dispersion of PPCPs in surface waters over the past ten years and identifying the mechanisms of PPCPs removal in CWs based on the up-to-present research, with a special focus on the contribution of sediments, vegetation, and the interactions of microorganisms. The significant role of wetland plants in the removal of PPCPs was detailed discussed in identifying the contribution of direct uptake, adsorption, phytovolatilization, and biodegradation. Meanwhile, the correlation between the physical-chemical characteristics of PPCPs, the configuration operation of wetlands, as well as the environmental conditions with PPCP removal were also further estimated. Finally, the critical issues and knowledge gaps before the real application were addressed followed by promoted future works, which are expected to provide a comprehensive foundation for study on PPCPs elimination utilizing CWs and drive to achieve large-scale applications to treat PPCPs-contaminated surface waters.

Magnetic Solid-Phase Extraction Based on Silica and Graphene Materials for Sensitive Analysis of Emerging Contaminants in Wastewater with the Aid of UHPLC-Orbitrap-MS

With the advancement of technology and nanotechnology, new extraction sorbents have been created and effectively used for the magnetic solid-phase extraction of target analytes. Some of the investigated sorbents have better chemical and physical properties, exhibiting high extraction efficiency and strong repeatability, combined with low detection and quantification limits. In this study graphene oxide (GO) magnetic composites were prepared and used as magnetic solid-phase extraction (MSPE) adsorbents along with synthesized silica based magnetic nanoparticles (MNPs) functionalized with the C18 group for the preconcentration of emerging contaminants (ECs) in wastewater samples generated from hospital and urban facilities. The sample preparation with magnetic materials was followed by UHPLC-Orbitrap MS analysis for the accurate identification and determination of trace amounts of pharmaceutical active compounds and artificial sweeteners in effluent wastewater. Optimal conditions were used for the extraction of ECs from the aqueous samples, prior to UHPLC-Orbitrap MS determination. The proposed methods achieved low quantitation limits between 1.1-33.6 ng L^-1 and 1.8-98.7 ng L^-1 and satisfactory recoveries in the range of 58.4%-102.6%. An intra-day precision of less than 23.1% was achieved, while inter-day RSD% values in the range of 5.6-24.8% were observed. These figures of merit suggest that our proposed methodology is suitable for the determination of target ECs in aquatic systems.

A year-long study of the occurrence and risk of over 140 contaminants of emerging concern in wastewater influent, effluent and receiving waters in the Republic of Ireland

Despite being a developed country in the European Union (EU), knowledge of the nature and extent of contamination of water bodies with contaminants of emerging concern (CECs) in Ireland is limited. In this study, >140 CECs including pharmaceuticals, pesticides and personal care products were monitored in monthly samples of wastewater treatment plant (WWTP) influent, effluent and receiving surface waters at both an urban and a rural location (72 samples in total) in Ireland over a 12-month period in 2018-2019. In total, 58 CECs were detected, including several EU Water Framework Directive Watch List compounds. Of all classes, the highest concentrations were measured for pharmaceuticals across all media, i.e., propranolol in surface waters (134 ng·L^-1), hydrochlorothiazide in effluent (1067 ng·L^-1) and venlafaxine in influent wastewater (8273 ng·L^-1). Overall, high wastewater treatment removal was observed and a further reduction in CEC occurrence and concentration was measured via dilution in the receiving river environment. Lastly, an environmental risk assessment (ERA) was performed using risk quotients (RQ), which revealed that in surface waters, total RQ for all CECs was an order of magnitude lower than in effluents. The majority of CECs in surface waters posed a lower risk except E2 and EE2 which presented a medium risk (RQs of 3.5 and 1.1, respectively) in the rural area. This work represents the most comprehensive CEC monitoring dataset to date for Ireland which allowed for an ERA prioritisation to be performed for the first time.

Wide-scope target screening characterization of legacy and emerging contaminants in the Danube River Basin by liquid and gas chromatography coupled with high-resolution mass spectrometry

A state-of-the-art wide-scope target screening of 2,362 chemicals and their transformation products (TPs) was performed in samples collected within the Joint Danube Survey 4 (JDS4) performed in 2019. The analysed contaminants of emerging concern (CECs) included three major categories: plant protection products (PPPs), industrial chemicals and pharmaceuticals and personal care products (PPCPs). In total, 586 CECs were detected in the samples including 158 PPPs, 71 industrial chemicals, 348 PPCPs, and 9 other chemicals. A wide-variety of sample matrices were collected including influent and effluent wastewater, groundwater, river water, sediment and biota. Forty-five CECs (19 PPPs, 8 industrial chemicals, 18 PPCPs) were detected at levels above their ecotoxicological thresholds (lowest predicted no-effect concentration (PNEC) values) in one or more of the investigated environmental compartments, indicating potential adverse effects on the impacted ecosystems. Among them 12 are legacy substances; 33 are emerging and qualify as potential Danube River Basin Specific Pollutants (RBSPs). Moreover, the efficiency of the wastewater treatment plants (WWTPs) was evaluated using 20 selected performance indicator chemicals. WWTPs showed effective removal (removal rate ≥80%) and medium removal (removal rate 25-80%) for 6 and 8 of the indicator chemicals, respectively. However, numerous contaminants passed the WWTPs with a lower removal rate. Further investigation on performance of WWTPs is suggested at catchment level to improve their removal efficiency. WWTP effluents are proven to be one of the major sources of contaminants in the Danube River Basin (DRB). Other sources include sewage discharges, industrial and agricultural activities. Continuous monitoring of the detected CECs is suggested to ensure water quality of the studied area.

Long-term effects on the agroecosystem of using reclaimed water on commercial crops

The use of reclaimed water for crop irrigation has been proposed as a suitable alternative for farmers in the coastal areas of Mediterranean countries, which suffer from greater water scarcity. In this work we study the impact on the water-soil-plant continuum of using reclaimed water for commercial crops irrigated over a long period, as well as the human risks associated with consuming the vegetables produced. Forty-four CECs were identified in the reclaimed water used for crop irrigation. Of these, twenty-four CECs were identified in the irrigated soil samples analysed. Tramadol, ofloxacin, tonalide, gemfibrozil, atenolol, caffeine, and cetirizine were the pharmaceuticals detected at the highest levels in the water samples (between 11 and 44 μg/L). The CECs with the highest average soil concentrations were tramadol (14.6 μg/kg), followed by cetirizine (13.2 μg/kg) and clarithromycin (12.7 μg/kg). In the irrigated vegetable samples analysed over the study period, carbamazepine, lidocaine, and caffeine were only detected at levels from 0.1 to 1.7 μg/kg. The CEC accumulation rate detected in the edible parts of the vegetables permanently irrigated with reclaimed water was very low (~1 %), whereas it was 33 % in the soils. The results revealed that consuming fruits harvested from plants irrigated for a long period with reclaimed water does not represent a risk to human health, opening the door to a circular economy of water. Nevertheless, for crop irrigation, future studies need to be conducted over longer periods and in other matrices to provide more scientific data on the safety of using reclaimed water.

Bisphenol A and its substitutes in the aquatic environment: Occurrence and toxicity assessment

Bisphenol A is classified as a high production volume chemical commonly used in the manufacture of polycarbonate plastics, epoxy resins and thermal paper. The endocrine disrupting properties of this xenobiotic have led to the restriction and prohibition of its use in many consumer products. To date, many chemical compounds with a chemical structure similar to bisphenol A have been used in consumer products as its replacement. The ubiquitous occurrence of bisphenol A and its substitutes in the environment and their endocrine activity as well as adverse effects on aquatic organisms is a global concern, especially because many available literature reports show that many substitutes (e.g. bisphenol AF, bisphenol AP, bisphenol B, bisphenol C, bisphenol F, bisphenol G, bisphenol FL, tetrabromobisphenol A) exert adverse effects on aquatic organisms, similar to, or even stronger than bisphenol A. Therefore, the objective of this paper is to provide a comprehensive overview of the production, sources, occurrence and associated toxicity, as well as the endocrine activity of bisphenol A and its substitutes on aquatic species. The environmental levels and ecotoxicological data presented in this review allowed for a preliminary assessment and prediction of the risk of bisphenol A and its substitutes for aquatic organisms. Furthermore, the data collected in this paper highlight that several compounds applied in bisphenol A-free products are not safe alternatives and regulations regarding their use should be introduced.

Using zebrafish embryo bioassays to identify chemicals modulating the regulation of the epigenome: a case study with simvastatin

Contaminants of emerging concern have been increasingly associated with the modulation of the epigenome, leading to potentially inherited and persistent impacts on apical endpoints. Here, we address the performance of the OECD Test No. 236 FET (fish embryo acute toxicity) in the identification of chemicals able to modulate the epigenome. Using zebrafish (Danio rerio) embryos, acute and chronic exposures were performed with the pharmaceutical, simvastatin (SIM), a widely prescribed hypocholesterolemic drug reported to induce inter and transgenerational effects. In the present study, the epigenetic effects of environmentally relevant concentrations of SIM (from 8 ng/L to 2000 ng/L) were addressed following (1) an acute embryo assay based on OECD Test No. 236 FET, (2) a chronic partial life-cycle exposure using adult zebrafish (90 days), and (3) F1 embryos obtained from parental exposed animals. Simvastatin induced significant effects in gene expression of key epigenetic biomarkers (DNA methylation and histone acetylation/deacetylation) in the gonads of exposed adult zebrafish and in 80 hpf zebrafish embryos (acute and chronic parental intergenerational exposure), albeit with distinct effect profiles between biological samples. In the chronic exposure, SIM impacted particularly DNA methyltransferase genes in males and female gonads, whereas in F1 embryos SIM affected mostly genes associated with histone acetylation/deacetylation. In the embryo acute direct exposure, SIM modulated the expression of both genes involved in DNA methylation and histone deacetylase. These findings further support the use of epigenetic biomarkers in zebrafish embryos in a high throughput approach to identify and prioritize epigenome-modulating chemicals.

Treatment Trends and Combined Methods in Removing Pharmaceuticals and Personal Care Products from Wastewater-A Review

When discharged into wastewater, pharmaceuticals and personal care products (PPCPs) become microorganic contaminants and are among the largest groups of emerging pollutants. Human, animal, and aquatic organisms' exposures to PPCPs have linked them to an array of carcinogenic, mutagenic, and reproductive toxicity risks. For this reason, various methods are being implemented to remove them from water bodies. This report critically reviews these methods and suggests improvements to removal strategies. Biological, physical, and chemical methods such as biological degradation, adsorption, membrane filtration, and advanced electrical and chemical oxidation are the common methods used. However, these processes were not integrated into most studies to take advantage of the different mechanisms specific to each process and are synergistic in the removal of the PPCPs that differ in their physical and chemical characteristics (charge, molecular weight, hydrophobicity, hydrogen bonding, structure). In the review articles published to date, very little information is available on the use of such integrated methods for removing PPCPs. This report attempts to fill this gap with our knowledge.

Photocatalytic Degradation of Inherent Pharmaceutical Concentration Levels in Real Hospital WWTP Effluents Using g-C(3)N(4) Catalyst on CPC Pilot Scale Reactor

The objective of this work was to evaluate the efficiency of a solar photocatalytic process using g-C₃N₄ as photocatalyst on the degradation of pharmaceutical compounds detected in hospital wastewater treatment plant secondary effluents. A compound parabolic collector pilot plant, established in the secondary effluent stream of the Ioannina city hospital wastewater treatment plant, was used for the photocatalytic experiments. The analysis of the samples before and after the photocatalytic treatment was accomplished using solid phase extraction (SPE), followed by UHPLC-LTQ/Orbitrap HRMS. Initial effluent characterization revealed the presence of ten pharmaceutical compounds. Among these, amisulpride, O-desmethyl venlafaxine, venlafaxine and carbamazepine were detected in all experiments. Initial concentrations ranged from 73 ng L^-1 for citalopram to 2924.53 ng L^-1 for O-desmethyl venlafaxine. The evolution of BOD₅ and COD values were determined before and after the photocatalytic treatment. All detected pharmaceuticals were removed in percentages higher than 54% at an optimum catalyst loading ranging between 200 and 300 mg L^-1. The potential of the catalyst to be reused without any treatment for two consecutive cycles was studied, showing a significant efficiency decrease.

Efficient peroxymonosulfate activation by biochar-based nanohybrids for the degradation of pharmaceutical and personal care products in aquatic environments

Recently, pharmaceutical and personal care products (PPCPs) have been of wide concern due to their ecological toxicity, persistence, and ubiquity in aquatic environments. Peroxymonosulfate-based advanced oxidation processes (PMS-AOPs) have shown great potential for eliminating PPCPs due to their superior oxidation ability and adaptability. Biochar-based nanohybrids have been employed as emerging catalysts for peroxymonosulfate (PMS) activation. Until now, few researchers have summarized PMS activation by biochar-based catalysts for PPCPs removal. In this review, the types, sources, fates, and ecological toxicities of PPCPs were first summarized. Furthermore, various preparation and modification methods of biochar-based catalysts were systematically introduced. Importantly, the application of activating PMS with biochar-based multifunctional nanocomposites for eliminating PPCPs was reviewed. The influencing factors, such as catalysts dosage, PMS dosage, solution pH, temperature, anions, natural organic matters (NOMs), and pollutants concentration were broadly discussed. Biochar-based catalysts can act as electron donors, electron acceptors, and electron shuttles to activate PMS for the removal of PPCPs through radical pathways or/and non-radical pathways. The degradation mechanisms of PPCPs are correlated with persistent free radicals (PFRs), metal species, defective sites, graphitized degree, functional groups, electronic attributes, and the hybridization modes of biochar-based catalysts. Finally, the current problems and further research directions on the industrial application of biochar-based nanocomposites were proposed. This study provides some enlightenment for the efficient removal of PPCPs with biochar-based catalysts in PMS-AOPs.

Antibiotic Toxicity Isolated and as Binary Mixture to Freshwater Algae Raphidocelis subcapitata: Growth Inhibition, Prediction Model, and Environmental Risk Assessment

Antibiotics in aqueous environments can have extremely adverse effects on non-targeted organisms. However, many research projects have only focused on the toxicological evaluation of individual antibiotics in various environments. In the present work, individual and binary mixture toxicity experiments have been conducted with the model organism Raphidocelis subcapitata (R. subcapitata), and a mixture concentration-response curve was established and contrasted with the estimated effects on the basis of both the concentration addition (CA) and the independent action (IA) models. In addition, different risk assessment methods were used and compared to evaluate the environmental risk of binary mixtures. The toxic ranking of the selected antibiotics to R. subcapitata was erythromycin (ERY) > sulfamethoxazole (SMX) > sulfamethazine (SMZ). In general, the conclusion of this study is that the adverse effects of binary mixtures are higher than the individual antibiotics. The CA model and RQSTU are more suitable for toxicity prediction and risk assessment of binary mixtures. This study reveals the potential ecological risks that antibiotics and their mixtures may pose to water ecosystems, thus providing scientific information for environmental quality regulation.

Removal of Non-Steroidal Anti-Inflammatory Drugs from Drinking Water Sources by GO-SWCNT Buckypapers

Pharmaceutical products such as antibiotics, analgesics, steroids, and non-steroidal anti-inflammatory drugs (NSAIDs) are new emerging pollutants, often present in wastewater, potentially able to contaminate drinking water resources. Adsorption is considered the cheapest and most effective technique for the removal of pollutants from water, and, recently, membranes obtained by wet filtration method of SWCNT aqueous solutions (SWCNT buckypapers, SWCNT BPs) have been proposed as self-standing porous adsorbents. In this paper, the ability of graphene oxide/single-walled carbon nanotube composite membranes (GO-SWCNT BPs) to remove some important NSAIDs, namely Diclofenac, Ketoprofen, and Naproxen, was investigated at different pH conditions (pH 4, 6, and 8), graphene oxide amount (0, 20, 40, 60, and 75 wt.%), and initial NSAIDs concentration (1, 10, and 50 ppm). For the same experimental conditions, the adsorption capacities were found to strongly depend on the graphene oxide content. The best results were obtained for 75 wt.% graphene oxide with an adsorption capacity of 118 ± 2 mg g^-1 for Diclofenac, 116 ± 2 mg g^-1 for Ketoprofen, and 126 ± 3 mg g^-1 for Naproxen at pH 4. Overall, the reported data suggest that GO-SWCNT BPs can represent a promising tool for a cheap and fast removal of NSAIDs from drinking water resources, with easy recovery and reusability features.

Occurrence, transport and environmental risk assessment of pharmaceuticals and personal care products (PPCPs) at the mouth of Jiaozhou Bay, China based on stir bar sorptive extraction

In recent years, research on pharmaceuticals and personal care products (PPCPs) in the marine environment has attracted increasing attention worldwide. However, more work is needed to improve PPCPs detection methods, specifically for seawater environments. An analytical method based on stir bar sorptive extraction (SBSE) had been developed and fully optimized for the pretreatment and detection of ten widely used PPCPs that are commonly found in seawater samples. By optimizing several variables including the material of the stir bars, extraction temperature, extraction time, ionic strength, desorption solvent, and desorption time, the optimized method has achieved excellent results in the detection and quantification of target PPCPs with detection limits ranging from 0.03 to 1 ng/L. The distribution of target PPCPs at the mouth of Jiaozhou Bay was successfully determined by this method, and the concentrations and detection frequencies of PPCPs varied greatly from N.D. to 449.36 ng/L and from 9.1 % to 100 %, respectively. Moreover, the distributions of PPCPs were explained by the Lagrangian particle-tracking model, and the results showed that the Tuandao sewage treatment plant had the most significant impact on the study area. The environmental risk assessment results showed that several target PPCPs might pose risks to aquatic organisms. In particular, triclocarban should receive more attention and the risk quotients of the mixtures (MRQ) should not be ignored.

Enzyme immobilization on biomass-derived carbon materials as a sustainable approach towards environmental applications

Enzymes with their environment-friendly nature and versatility have become highly important 'green tools' with a wide range of applications. Enzyme immobilization has further increased the utility and efficiency of these enzymes by improving their stability, reusability, and recyclability. Biomass-derived matrices when used for enzyme immobilization offer a sustainable solution to environmental pollution and fuel depletion at low costs. Biochar and other biomass-derived carbon materials obtained are suitable for the immobilization of enzymes through different immobilization strategies. Environmental pollution has become an utmost topic of research interest due to an ever-increasing trend being observed in anthropogenic activities. This has widely contributed to the release of various toxic effluents into the environment in their native or metabolized forms. Therefore, more focus is being directed toward the utilization of immobilized enzymes in the bioremediation of water and soil, biofuel production, and other environmental applications. In this review, up-to-date literature concerning the immobilization and potential uses of enzymes immobilized on biomass-derived carbon materials has been presented.

Occurrence and distribution of antibiotics in coastal water of the Taizhou Bay, China: impacts of industrial activities and marine aquaculture

The occurrence, spatial distribution, and source analysis of antibiotics in global coastal waters and estuaries are not well documented or understood. Therefore, the distribution of 14 antibiotics in inflowing river and bay water of Taizhou Bay, East China Sea, was studied. Thirteen antibiotics, excluding roxithromycin (ROM), were all detected in inflowing river and bay water. The total antibiotic concentrations in bay water ranged from 3126.62 to 26,531.48 ng/L, which were significantly higher than those in the inflowing river (17.20-25,090.25 ng/L). Macrolides (MAs) and sulfonamides (SAs) were dominant in inflowing river (accounting for 24.40% and 74.9% of the total antibiotic concentrations, respectively), while SAs in bay water (93.6% of the total concentrations). Among them, clindamycin (CLI) (concentration range: ND-8414 ng/L, mean 1437.59 ng/L) and sulfadimidine (SMX) (ND-25,184.00 ng/L, mean concentrations: 9107.88 ng/L) were the highest in those surface water samples. Source analysis showed that MAs and SAs in the inflowing river mainly came from the wastewater discharge of the surrounding residents and pharmaceutical companies, while SAs in the bay water mainly came from surrounding industrial activities and mariculture. However, the contribution of the inflowing river to the bay water cannot be ignored. The risk assessment showed that SMX and ofloxacin (OFX) have potential ecological risks. These data will support the various sectors of the environment in developing management strategies and to prevent antibiotic pollution.

Adsorption of caffeine using steel wastes

Caffeine is the most widespread active pharmaceutical compound in the world, generally studied as a tracer of human pollution, since caffeine levels in surface water correlate with the anthropogenic load of domestic wastewater. This work investigated the use of different steel wastes named as SW-I, SW-II, SW-II, SW-IV, SW-V, and SW-VI in the adsorption of caffeine. These materials were pretreated and characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and point of zero charge. The samples are mainly composed of iron (hematite and magnetite). The caffeine adsorption test indicated that SW-VI (steel slag dust) is the most efficient and promising (removal around 51.68%) in relation to the other residues, which it was selected for further studies. Equilibrium time was reached within 96 h of contact between the adsorbent and the adsorbate, with removal of 84.00%, 81.09%, and 73.19% for the initial concentrations of 10 mg L^-1, 20 mg L^-1, and 30 mg L^-1 of caffeine. The pseudo-first-order, pseudo-second-order, and Elovich models presented a good fit to the experimental data. However, the pseudo-first order model described better the experimental behavior. Adsorption isotherms were performed at three temperatures (298, 308, and 318 K). The maximum adsorption capacity was 17.46 ± 2.27 mg g^-1, and experimental data were better fitted by the Sips isotherm. Values of ΔG° and parameters equilibrium of the models of Langmuir, Sips, and Temkin were calculated from the standard enthalpies and standard entropies estimated. The values of ΔG° were negative for the temperatures studied indicating that the adsorption process is viable and spontaneous. Negative values for ΔH° were also found, indicating that the process of caffeine adsorption by SW-VI is an exothermic process (0 to -40 kJ mol^-1). Thus, the adsorption of caffeine by SW-VI is a physical process. The SW-VI material showed economic viability and promising for the adsorption of caffeine in aqueous media.

Global groundwater vulnerability for Pharmaceutical and Personal care products (PPCPs): The scenario of second decade of 21st century

The global production of PPCPs have increased by multiple folds promoting excessive exposure of its metabolites to humans via different aquatic systems. The higher residence time of toxic precursors of these metabolites pose direct human health risk. Among the different aquatic systems, the contamination of groundwater by PPCPs is the most concerning threat. This threat is especially critical considering the lesser oxidizing potential of the groundwater as compared to freshwater/river water. A major challenge also arises due to excessive dependency of the world's population on groundwater, which is exponentially increasing with time. This makes the identification and characterization of spatial contamination hotspots highly probabilistic as compared to other freshwater systems. The situation is more vulnerable in developing countries where there is a reported inadequacy of wastewater treatment facilities, thereby forcing the groundwater to behave as the only available sequestrating sink for all these contaminants. With increased consumption of antibiotics and other pharmaceuticals compounds, these wastes have proven capability in terms of enhancing the resistance among the biotic community of the soil systems, which ultimately can become catastrophic and carcinogenic in near future. Recent studies are supporting the aforementioned concern where compounds like diclofenac (analgesic) have attained a concentration of 1.3 mgL^-1 in the aquifer systems of Delhi, India. The situation is far worse for developed nations where prolonged and indiscriminate usage of antidepressants and antibiotics have life threating consequences. It has been confirmed that certain compounds like ofloxacin (antibiotics) and bis-(2-ethylhexyl)phthalate are present in some of the most sensitive wells/springs of the United States and Mexico. The current trend of the situation has been demonstrated by integrating a comparative approach of the published literatures in last three years. This review provides first-hand information report for formulating a directive policy framework for tackling PPCPs issues in the groundwater system.

Fate of selected pharmaceuticals in hospital and municipal wastewater effluent: occurrence, removal, and environmental risk assessment

The concentrations and distribution of β-blockers, lipid regulators, and psychiatric and cancer drugs in the influent and effluent of the municipal wastewater treatment plant (WWTP) and the effluent of 16 hospitals that discharge into the wastewater treatment plant mentioned in this study at two sampling dates in summer and winter were examined. The pharmaceutical contribution of hospitals to municipal wastewater was determined. The removal of target pharmaceuticals was evaluated in a WWTP consisting of conventional biological treatment using activated sludge. Additionally, the potential environmental risk for the aquatic receiving environments (salt lake) was assessed. Beta-blockers and psychiatric drugs were detected in high concentrations in the wastewater samples. Atenolol (919 ng/L) from β-blockers and carbamazepine (7008 ng/L) from psychiatric pharmaceuticals were detected at the highest concentrations in hospital wastewater. The total pharmaceutical concentration determined at the WWTP influent and effluent was between 335 and 737 ng/L in summer and between 174 and 226 ng/L in winter. The concentrations detected in hospital effluents are higher than the concentrations detected in WWTP. The total pharmaceutical contributions from hospitals to the WWTP in summer and winter were determined to be 2% and 4%, respectively. Total pharmaceutical removal in the WWTP ranged from 23 to 54%. According to the risk ratios, atenolol could pose a high risk (risk quotient > 10) for fish in summer and winter. There are different reasons for the increase in pharmaceutical consumption in recent years. One of these reasons is the COVID-19 pandemic, which has been going on for 2 years. In particular, hospitals were operated at full capacity during the pandemic, and the occurrence and concentration of pharmaceuticals used for the therapy of COVID-19 patients has increased in hospital effluent. Pandemic conditions have increased the tendency of people to use psychiatric drugs. It is thought that beta-blocker consumption has increased due to cardiovascular diseases caused by COVID-19. Therefore, the environmental risk of pharmaceuticals for aquatic organisms in hospital effluent should be monitored and evaluated.

Impacts of the COVID-19 pandemic on pharmaceuticals in wastewater treated for beneficial reuse: Two case studies in central Pennsylvania

During the COVID-19 pandemic, wastewater surveillance was leveraged as a powerful tool for monitoring community-scale health. Further, the well-known persistence of some pharmaceuticals through wastewater treatment plants spurred concerns that increased usage of pharmaceuticals during the pandemic would increase the concentrations in wastewater treatment plant effluent. We collected weekly influent and effluent samples from May 2020 through May 2021 from two wastewater treatment plants in central Pennsylvania, the Penn State Water Reclamation Facility and the University Area Joint Authority, that provide effluent for beneficial reuse, including for irrigation. Samples were analyzed for severe acute respiratory syndrome coronavirus 2 (influent only), two over-the-counter medicines (acetaminophen and naproxen), five antibiotics (ampicillin, doxycycline, ofloxacin, sulfamethoxazole, and trimethoprim), two therapeutic agents (remdesivir and dexamethasone), and hydroxychloroquine. Although there were no correlations between pharmaceutical and virus concentration, remdesivir detection occurred when the number of hospitalized patients with COVID-19 increased, and dexamethasone detection co-occurred with the presence of patients with COVID-19 on ventilators. Additionally, Penn State decision-making regarding instruction modes explained the temporal variation of influent pharmaceutical concentrations, with detection occurring primarily when students were on campus. Risk quotients calculated for pharmaceuticals with known effective and lethal concentrations at which 50% of a population is affected for fish, daphnia, and algae were generally low in the effluent; however, some acute risks from sulfamethoxazole were high when students returned to campus. Remdesivir and dexamethasone persisted through the wastewater treatment plants, thereby introducing novel pharmaceuticals directly to soils and surface water. These results highlight connections between human health and water quality and further demonstrate the broad utility of wastewater surveillance.

Prioritizing Pharmaceutical Contaminants in Great Lakes Tributaries Using Risk-Based Screening Techniques

In a study of 44 diverse sampling sites across 16 Great Lakes tributaries, 110 pharmaceuticals were detected of 257 monitored. The present study evaluated the ecological relevance of detected chemicals and identified heavily impacted areas to help inform resource managers and guide future investigations. Ten pharmaceuticals (caffeine, nicotine, albuterol, sulfamethoxazole, venlafaxine, acetaminophen, carbamazepine, gemfibrozil, metoprolol, and thiabendazole) were distinguished as having the greatest potential for biological effects based on comparison to screening-level benchmarks derived using information from two biological effects databases, the ECOTOX Knowledgebase and the ToxCast database. Available evidence did not suggest substantial concern for 75% of the monitored pharmaceuticals, including 147 undetected pharmaceuticals and 49 pharmaceuticals with screening-level alternative benchmarks. However, because of a lack of biological effects information, screening values were not available for 51 detected pharmaceuticals. Samples containing the greatest pharmaceutical concentrations and having the highest detection frequencies were from Lake Erie, southern Lake Michigan, and Lake Huron tributaries. Samples collected during low-flow periods had higher pharmaceutical concentrations than those collected during increased-flow periods. The wastewater-treatment plant effluent content in streams correlated positively with pharmaceutical concentrations. However, deviation from this correlation demonstrated that secondary factors, such as multiple pharmaceutical sources, were likely present at some sites. Further research could investigate high-priority pharmaceuticals as well as those for which alternative benchmarks could not be developed. Environ Toxicol Chem 2022;41:2221-2239. Published 2022. This article is a U.S. Government work and is in the public domain in the USA. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

First report on the occurrence of pharmaceuticals and cocaine in the coastal waters of Santa Catarina, Brazil, and its related ecological risk assessment

The worldwide occurrence of pharmaceuticals and personal care products (PPCPs) in aquatic ecosystems is reason for public concern. These emerging micropollutants include a large and diverse group of organic compounds, with continuous input, high environmental persistence and potential threat to biota and human health. The aim of this study was to evaluate, for the first time, the occurrence of twenty-seven PPCPs of various therapeutic classes (including cocaine and its primary metabolite, benzoylecgonine), in the coastal waters of Santa Catarina, southern Brazil. Water samples were taken in November 2020, during the low tide periods, at eight sampling points located along the coast of Santa Catarina, covering its entire geographical extension. Sampling was carried out in triplicate and at different depths of the water column. Nine compounds were detected through liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS): caffeine (12.58-119.80 ng/L), diclofenac (1.34-7.92 ng/L), atenolol (1.13-2.50 ng/L), losartan (0.43-3.20 ng/L), acetaminophen (0.21-10.04 ng/L), orphenadrine (0.07-0.09 ng/L), cocaine (0.02-0.17 ng/L), benzoylecgonine (0.01-1.1 ng/L) and carbamazepine (0.02-0.27 ng/L). The highest occurrence of these compounds was detected in the northern and central coastal region of Santa Catarina, namely in Penha and Palhoça cities. Moreover, the risk assessment showed that almost compounds (atenolol, benzoylecgonine, carbamazepine, cocaine and orphenadrine) presented no ecological risk in the recorded concentrations. However, a few compounds suggest low (caffeine and diclofenac) to moderate (acetaminophen and losartan) risk taking into consideration the acute and chronic effects for the three trophic levels (algae, crustacean and fish) tested. These compounds are usually found in areas with high population density, aggravated by tourism, because of the sanitary sewage and solid waste. Although in low concentrations, the occurrence of these chemical compounds can imply deleterious effects on the environmental health of Santa Catarina coastal zone, and therefore deserve more attention by the public authorities and environmental agencies.

A QSAR-ICE-SSD model prediction of the PNECs for alkylphenol substances and application in ecological risk assessment for rivers of a megacity

Alkylphenols (APs) are ubiquitous and generally present in higher residue levels in the environment. The present work focuses on the development of a set of in silico models to predict the aquatic toxicity of APs with incomplete/unknown toxicity data in aquatic environments. To achieve this, a QSAR-ICE-SSD model was constructed for aquatic organisms by combining quantitative structure-activity relationship (QSAR), interspecies correlation estimation (ICE), and species sensitivity distribution (SSD) models in order to obtain the hazardous concentrations (HCs) of selected APs. The research indicated that the keywords "alkylphenol" and "nonylphenol" were most commonly studied. The selected ICE models were robust (R2: 0.70-0.99; p-value < 0.01). All models had a high reliability cross- validation success rates (>75%), and the HC5 predicted with the QSAR-ICE-SSD model was 2-fold than that derived with measured experimental data. The HC5 values demonstrated nearly linear decreasing trend from 2-MP to 4-HTP, while the decreasing trend from 4-HTP to 4-DP became shallower, indicates that the toxicity of APs to aquatic organisms increases with the addition of alkyl carbon chain lengths. The ecological risks assessment (ERA) of APs revealed that aquatic organisms were at risk from exposure to 4-NP at most river stations (the highest risk quotient (RQ) = 1.51), with the highest relative risk associated with 2.9% of 4-NP detected in 82.9% of the sampling sites. The targeted APs posed potential ecological risks in the Yongding and Beiyun River according to the mixture ERA. The potential application of QSAR-ICE-SSD models could satisfy the immediate needs for HC5 derivations without the need for additional in vivo testing.

Occurrence of antibiotics and bacterial resistance genes in wastewater: resistance mechanisms and antimicrobial resistance control approaches

Antimicrobial pharmaceuticals are classified as emergent micropollutants of concern, implying that even at low concentrations, long-term exposure to the environment can have significant eco-toxicological effects. There is a lack of a standardized regulatory framework governing the permissible antibiotic content for monitoring environmental water quality standards. Therefore, indiscriminate discharge of antimicrobials at potentially active concentrations into urban wastewater treatment facilities is rampant. Antimicrobials may exert selective pressure on bacteria, leading to resistance development and eventual health consequences. The emergence of clinically important multiple antibiotic-resistant bacteria in untreated hospital effluents and wastewater treatment plants (WWTPs) has been linked to the continuous exposure of bacteria to antimicrobials. The levels of environmental exposure to antibiotics and their correlation to the evolution and spread of resistant bacteria need to be elucidated to help in the formulation of mitigation measures. This review explores frequently detected antimicrobials in wastewater and gives a comprehensive coverage of bacterial resistance mechanisms to different antibiotic classes through the expression of a wide variety of antibiotic resistance genes either inherent and/or exchanged among bacteria or acquired from the reservoir of antibiotic resistance genes (ARGs) in wastewater systems. To complement the removal of antibiotics and ARGs from WWTPs, upscaling the implementation of prospective interventions such as vaccines, phage therapy, and natural compounds as alternatives to widespread antibiotic use provides a multifaceted approach to minimize the spread of antimicrobial resistance.

A comparative study, distribution, predicted no-effect concentration (PNEC) and contamination assessment of phenol with heavy metal contents in two coastal areas on the Egyptian Mediterranean Sea coast

This study comparing the expected pollution status of phenol along with heavy metals in sediments of two economic regions on the Mediterranean Sea coast using equilibrium partitioning method (EPM) as well as exposure of fishermen and populations to these sediments through ingestion and skin contact while swimming. El-Dekhila (ED) and Abu Talat (AT) regions were different in sediment texture and pollution sources. The expected ecological hazards of phenol in the studied areas were carried out using the equilibrium partitioning method (EPM) by which the partition coefficient of organic carbon-water, K_OC (logK_OC> 0.95-3.49), octanol-water coefficient, K_OW (logK_OW> 1.46-1.48) and sediment/liquid partition coefficient, K_d (log K_d < 3) detected high availability amounts of phenol in seawater. Risk quotient (RQ) for phenol in ED region ranged from high to moderate risk, while for AT region was low risk (<0.1); whereas, RQ values of heavy metals in sediments of two studied areas reflected the overall low risk without human hazards (HQ & HI < 1). RQ_Acute and RQ_Chronic values were above 1 for phenol and heavy metals (Cu and Zn) reflecting that fish were the most sensitive to them in the two regions. Interestingly, this current investigation predicts future contamination of the studied areas especially phenol contamination and its relationship to heavy metals using some reasonable information and allowing the managers to manage how they decide on and protect these two areas. Thus, there is a constant need to use relatively simple tools capable of ensuring protection objectives with a quantity of information with realistic feasibility.

Degradation of Acyclovir by Zero-valent Iron Activated Persulfate Oxidation: Kinetics and Pathways Research

Acyclovir (ACV) is a commonly used antiviral drug; however, its poor bioavailability can lead to at least ng/L level residue in natural water. Sulfate radical, produced from persulfate (PS) by zero-valent iron (ZVI) activation, was demonstrated to effectively degrade ACV in this study. Influencing parameters, including ZVI dose, PS usage, initial ACV concentration, solution pH, and temperature, were evaluated to find the optimal degradation conditions. Intermediates were identified and main degradation pathways were proposed. Experiments showed that ACV degradation by ZVI/PS oxidation followed a pseudo zero-order reaction well (R² > 0.99). At pH ≦ 9, the optimal combination was 0.4 mM PS with 1.2 mM ZVI, in order to completely remove 10 μM ACV during 60-min reaction. Heat activation of PS would hinder the effect of ZVI if temperature was 45 °C or above. ACV could be oxidized to four major degradation products, including methoxyacetic acid (P1, C₃H₆O₃, m/z = 91), 1,1,2-trinitroethane (P2, C₂H₃N₃O₆, m/z = 165), trinitromethane (P3, CHN₃O₆, m/z = 151), and dinitromethane (P4, CH₂N₂O₄, m/z = 105). Though the mineralization rate was not high (about 24.0%), ZVI/PS oxidation was proved to be an available treatment method for ACV-induced water pollution.

Modeling Risk Dynamics of Contaminants of Emerging Concern in a Temperate-region Wastewater Effluent-dominated Stream

Wastewater effluent-dominated streams are becoming increasingly common worldwide, including in temperate regions, with potential impacts on ecological systems and drinking water sources. We recently quantified the occurrence/ spatiotemporal dynamics of pharmaceutical mixtures in a representative temperate-region wastewater effluent-dominated stream (Muddy Creek, Iowa) under baseflow conditions and characterized relevant fate processes. Herein, we quantified the ecological risk quotients (RQs) of 19 effluent-derived contaminants of emerging concern (CECs; including: 14 pharmaceuticals, 2 industrial chemicals, and 3 neonicotinoid insecticides) and 1 run-off-derived compound (atrazine) in the stream under baseflow conditions, and estimated the probabilistic risks of effluent-derived CECs under all-flow conditions (i.e., including runoff events) using stochastic risk modeling. We determined that 11 out of 20 CECs pose medium-to-high risks to local ecological systems (i.e., algae, invertebrates, fish) based on literature-derived acute effects under measured baseflow conditions. Stochastic risk modeling indicated decreased, but still problematic, risk of effluent-derived CECs (i.e., RQ≥0.1) under all-flow conditions when runoff events were included. Dilution of effluent-derived chemicals from storm flows thus only minimally decreased risk to aquatic biota in the effluent-dominated stream. We also modeled in-stream transport. Thirteen out of 14 pharmaceuticals persisted along the stream reach (median attenuation rate constant k<0.1 h^-1) and entered the Iowa River at elevated concentrations. Predicted and measured concentrations in the drinking water treatment plant were below the human health benchmarks. This study demonstrates the application of probabilistic risk assessments for effluent-derived CECs in a representative effluent-dominated stream under variable flow conditions (when measurements are less practical) and provides an enhanced prediction tool transferable to other effluent-dominated systems.

Sustainable Treatment Techniques for Emerging Pollutants—The Case of Personal Hygiene Products

Personal care products (PCPs) enter wastewater primarily through greywater. Treatment plants have not been able to remove this type of contaminant, although PCP abatement techniques have been developed in recent years. The objective of the current study has been to encounter the sustainable technique that keeps the optimal balance between the criteria considered in the comparison. Therefore, a bibliographic review was conducted in scientific databases of the last eight years, demonstrating that co-composting, anaerobic–aerobic sequencing bioreactors and contaminant absorption through the use of carbon nanotubes are the ones with the least environmental impact. Subsequently, the Saaty and Modified Saaty methods were applied, with a comparative criteria of construction costs, maintenance costs, efficiency and the stage of development. The results indicated that the co-composting technique is the best sustainable technique of those studied, with a score of 0.86/1, which means that the criteria analyzed maintain very close values between them. The co-composting technique yields a low environmental impact in eliminating personal care products. This research work constitutes a practical and easy-to-use tool for decision makers, since it allows finding an optimal elimination treatment for PCPs.

Effects of dissolved organic matter characteristics on the photosensitized degradation of pharmaceuticals in wastewater treatment wetlands

Wastewater treatment wetlands are aquatic systems where diverse dissolved organic matter (DOM) compositions physically interact. Complex photochemical behaviors ensue, leading to uncertainties in the prediction of indirect photodegradation rates for organic contaminants. Here, we evaluate the photosensitization ability of whole water DOM samples from a treatment wetland and wastewater treatment plant (WWTP) in North Carolina to photodegrade target pharmaceuticals. Optical characterization using ultraviolet-visible and excitation-emission matrix spectroscopy shows that wetland DOM has higher aromaticity than WWTP DOM and that WWTP secondary treatment processes increase aromaticity, overall molecular weight, and humic character of wastewater DOM. Our application of a reversed-phase HPLC method to assess DOM polarity distinctly reveals that a subset of the wetland samples possesses an abundance of hydrophobic DOM moieties. Hydroxyl radicals (˙OH) mediate the majority (>50%) of the indirect photodegradation for amoxicillin (AMX), atenolol (ATL), and 17α-ethinylestradiol (EE2), while singlet oxygen (¹O₂) is presumed to be solely responsible for the photodegradation of cimetidine (CME). Our findings suggest that hydrophobic interactions and improved accessibility to photogenerated reactive intermediates lead to significant increases in photosensitization efficiencies and overall indirect photodegradation rates of AMX, ATL, and EE2 for the hydrophobic wetland samples. In contrast, CME photosensitization yields are unaffected by polarity and trend positively with optical indicators of sunlight-induced DOM photobleaching and humification, suggesting that wetland processing favors faster ¹O₂ photogeneration. These relationships highlight the uncertainties in photosensitization yields and effects of DOM optical properties and polarity on the photochemical fate of organic contaminants.

Diclofenac removal from the wastewater using activated sludge and analysis of multidrug resistant bacteria from the sludge

Diclofenac is an anti-inflammatory drug and has been frequently detected from the wastewater. In the present study, factors affecting diclofenac adsorption on sewage sludge was evaluated. At 1 mg/L initial diclofenac concentration, more than 80% diclofenac removal was achieved. Adsorption increased at higher concentration (100 mg/L concentration) and more than 99% diclofenac was adsorbed from the wastewater. Significant removal of diclofenac was observed after 5 min contact time. The adsorption efficacy was more than 98% after 50 and 60 min. Pseudo-first and second order kinetics revealed reasonable regression value (0.9) indicated that the model is best fitted. Diclofenac adsorption was extremely high at acidic pHs than alkaline range. The sludge samples showed the presence of multi drug resistant bacteria. Vancomycin-resistant enterococcus stains were 27%, Methicillin-resistant Staphylococcus aureus positive strains were 16.5% and Extended-spectrum betal-lactamase-harbouring Enterobacteriacea were 65.4% in the sludge. The drug resistance Enterobacteriaceae revealed 14 Klebsiella pneumonia strains, 11 strains from E. coli and two from the genus Enterobacter. To conclude, the activated sludge could be effectively utilized for the removal of diclofenac from wastewater.

Occurrence, sources and environmental risk assessment of pharmaceuticals in the Sea of Marmara, Turkey

In the present study, the occurrence and spatial distribution of selected eleven pharmaceuticals were investigated in the Sea of Marmara, Turkey. Samples were collected from different depths of the nine stations in April and October 2019. Pharmaceuticals were analyzed using liquid-liquid and solid-phase extraction (SPE) methods followed by high-performance liquid chromatography (HPLC). All target pharmaceutical compounds were detected at least once in the study area. Gemfibrozil, which belongs to the lipid regulatory group, was the most frequently detected in seawater at high concentrations (<0.016-9.71 μg/L). Ibuprofen (<0.015-2.13 μg/L) and 17α-ethynylestradiol (<0.010-3.55 μg/L) were identified as the other frequently detected pharmaceuticals. In addition, the presence of these selected compounds in April was higher than in October. According to the risk assessment results, naproxen, diclofenac, clofibric acid, gemfibrozil, 17β-estradiol, and 17α-ethynylestradiol represent a high risk to aquatic organisms in the Sea of Marmara. These findings underline the importance of continued monitoring of these compounds as relevant organic contaminants in the study area to take appropriate measures to protect the ecosystem and, ultimately, human health.