Behavior of pharmaceuticals, cosmetics and hormones in a sewage treatment plant

Occurrence and distribution of emerging contaminants in wastewater treatment plants: A globally review over the past two decades

Emerging contaminants are pervasive in aquatic environments globally, encompassing pharmaceuticals, personal care products, steroid hormones, phenols, biocides, disinfectants and various other compounds. Concentrations of these contaminants are detected ranging from ng/L to μg/L. Even at trace levels, these contaminants can pose significant risks to ecosystems and human health. This article systematically summarises and categorizes data on the concentrations of 54 common emerging contaminants found in the influent and effluent of wastewater treatment plants across various geographical regions: North America, Europe, Oceania, Africa, and Asia. It reviews the occurrence and distribution of these contaminants, providing spatial and causal analyses based on data from these regions. Notably, the maximum concentrations of the pollutants observed vary significantly across different regions. The data from Africa, in particular, show more frequent detection of pharmaceutical maxima in wastewater treatment plants.

The behavior of pharmaceutically active compounds and contrast agents during wastewater treatment - Combining sampling strategies and analytical techniques: A critical review

Increasing consumption of pharmaceuticals and the respective consequences for the aquatic environment have been the focus of many studies over the last thirty years. Various aspects in this field were investigated, considering diverse pharmaceutical groups and employing a wide range of research methodologies. Various questions from the perspectives of different research areas were devised and answered, resulting in a large mix of individual findings and conclusions. Collectively, the results of the studies offer a comprehensive overview. The large variety of methods and strategies, however, demands close attention when comparing and combining information from heterogeneous projects. This review critically examines the application of diverse sampling techniques as well as analytical methods in investigations concerning the behavior of pharmaceutically active compounds (PhACs) and contrast agents (CAs) in wastewater treatment plants (WWTPs). The combination of sampling and analysis is discussed with regard to its suitability for specific scientific problems. Different research focuses need different methods and answer different questions. An overview of studies dealing with the fate and degradation of PhACs and CAs in WWTPs is presented, discussing their strategic approaches and findings. This review includes surveys of anticancer drugs, antibiotics, analgesics and anti-inflammatory drugs, antidiabetics, beta blockers, hormonal contraceptives, lipid lowering agents, antidepressants as well as contrast agents for X-ray and magnetic resonance imaging.

Aqueous photolysis of naproxen exposed to UV and natural sunlight: Formation of excited triplet and photosensitizing product

Photochemical transformation is an important attenuation process for the non-steroidal anti-inflammatory drug naproxen (NPX) in both engineered and natural waters. Herein, we investigated the photolysis of NPX in aqueous solution exposed to both ultraviolet (UV, 254 nm) and natural sunlight irradiation. Results show that N2 purging significantly promoted NPX photolysis under UV irradiation, suggesting the formation of excited triplet state (3NPX*) as a critical transient. This inference was supported by benzophenone photosensitization and transient absorption spectra. Sunlight quantum yield of NPX was only one fourteenth of that under UV irradiation, suggesting the wavelength-dependence of NPX photochemistry. 3NPX* formed upon irradiation of NPX underwent photodecarboxylation leading to the formation of 2-(1-hydroxyethyl)-6-methoxynaphthalene (2HE6MN), 2-(1-hydroperoxyethyl)-6-methoxynaphthalene (2HPE6MN), and 2-acetyl-6-methoxynaphthalene (2A6MN). Notably, the conjugation and spin-orbit coupling effects of carbonyl make 2A6MN a potent triplet sensitizer, therefore promoting the photodegradation of the parent NPX. In hospital wastewater, the photolysis of NPX was influenced because the photoproduct 2A6MN and wastewater components could competitively absorb photons. Bioluminescence inhibition assay demonstrated that photoproducts of NPX exhibited higher toxicity than the parent compound. Results of this study provide new insights into the photochemical behaviors of NPX during UV treatment and in sunlit surface waters.

Review on antibiotic pollution dynamics: insights to occurrence, environmental behaviour, ecotoxicity, and management strategies

Antibiotic contamination poses a significant global concern due to its far-reaching impact on public health and the environment. This comprehensive review delves into the prevalence of various antibiotic classes in environmental pollution and their interactions with natural ecosystems. Fluoroquinolones, macrolides, tetracyclines, and sulphonamides have emerged as prevalent contaminants in environmental matrices worldwide. The concentrations of these antibiotics vary across diverse environments, influenced by production practices, consumer behaviours, and socio-economic factors. Low- and low-middle-income countries face unique challenges in managing antibiotic contamination, with dominant mechanisms like hydrolysis, sorption, and biodegradation leading to the formation of toxic byproducts. Ecotoxicity reports reveal the detrimental effects of these byproducts on aquatic and terrestrial ecosystems, further emphasizing the gravity of the issue. Notably, monitoring the antibiotic parent compound alone may be inadequate for framing effective control and management strategies for antibiotic pollution. This review underscores the imperative of a comprehensive, multi-sectoral approach to address environmental antibiotic contamination and combat antimicrobial resistance. It also advocates for the development and implementation of tailored national action plans that consider specific environmental conditions and factors. Thus, an approach is crucial for safeguarding both public health and the delicate balance of our natural ecosystems.

Occurrence, removal, and prioritization of organic micropollutants in four full-scale wastewater treatment plants in Korea

This study investigated the occurrence, removal rate, and potential risks of 43 organic micropollutants (OMPs) in four municipal wastewater treatment plants (WWTPs) in Korea. Results from two-year intensive monitoring confirmed the presence of various OMPs in the influents, including pharmaceuticals such as acetaminophen (pain relief), caffeine (stimulants), cimetidine (H2-blockers), ibuprofen (non-steroidal anti-inflammatory drugs- NSAIDs), metformin (antidiabetics), and naproxen (NSAIDs) with median concentrations of >1 μg/L. Some pharmaceuticals (carbamazepine-anticonvulsants, diclofenac-NSAIDs, propranolol-β-blockers), corrosion inhibitors (1H-benzotriazole-BTR, 4-methyl-1H-benzotriazole-4-TTR), and perfluorinated compounds (PFCs) were negligibly removed during WWTP treatment. The OMP concentrations in the influents and effluents were mostly lower in August than those of other months (p-value <0.05) possibly due to wastewater dilution by high precipitation or enhanced biodegradation under high-temperature conditions. The anaerobic-anoxic-oxic process (A2O) with a membrane bioreactor exhibited higher OMP removal than other processes, such as A2O with sedimentation or the conventional activated sludge process (p-value <0.05). Pesticides (DEET and atrazine), corrosion inhibitors (4-TTR and BTR), and metformin were selected as priority OMPs in toxicity-driven prioritization, whereas PFCs were determined as priority OMPs given their persistence and bioaccumulation properties. Overall, our results contribute to an important database on the occurrence, removal, and potential risks of OMPs in Korean WWTPs.

Limitations of wastewater treatment plants in removing trace anthropogenic biomarkers and future directions: A review

This review highlights the limitations faced by conventional wastewater treatment plants (WWTPs) in effectively removing contaminants of emerging concern (CECs), heavy metals (HMs), and Escherichia coli (E. coli). This emphasises the limitations of current treatment methods and advocates for innovative approaches to enhance the removal efficiency. By following the PRISMA guidelines, the study systematically reviewed relevant literature on detecting and remedying these pollutants in wastewater treatment facilities. Conventional wastewater treatment plants struggle to eliminate CECs, HMs, and E. coli owing to their small size, persistence, and complex nature. The review suggests upgrading WWTPs with advanced tertiary processes to significantly improve contaminant removal. This calls for cost-effective treatment parameters and standardised assessment techniques to enhance the fate of MPs in WWTPs and WRRFs. It recommends integrating insights from mass-balance model studies on MPs in WWTP to overcome modelling challenges and ensure model reliability. In conclusion, this review underscores the urgent need for advancements in wastewater treatment processes to mitigate the environmental impact of trace anthropogenic biomarkers. Future efforts should focus on conducting comprehensive studies, implementing advanced treatment methods, and optimising management practices in WWTPs and WRRFs.

Impact of long-term temperature shifts on activated sludge microbiome dynamics and micropollutant removal

Micropollutants removal efficiency strongly vary across different aerobic wastewater treatment plants, resulting in their frequent detection in surface and ground waters. Seasonal temperature variation is a major factor influencing plant performance, but it is still unclear how prolonged periods of temperature change impact microbiome and micropollutant biotransformation. This work investigates the effect of long-term temperature variation on the microbial dynamics in an activated sludge system, and the impact on micropollutant biotransformation. Sequencing batch reactors were used as model system and 4-40 °C temperature range was studied. 16S rRNA amplicon sequencing showed that temperature drives microbial structure (gDNA) and activity (RNA), rather than time, and this was stronger below 15 °C and above 25 °C. The microbial community was richest and more diverse at 20 °C, while rarer and more specific taxa became predominant over time, at more extreme temperatures. This suggested that less abundant taxa might be responsible for maintaining the biotransformation capability in the activated sludge at extreme temperatures. Micropollutant biotransformation rates mostly deviated from the classic Arrhenius model below 15 °C and above 25 °C, indicating that prolonged exposure to temperature changes leads to temperature-induced taxonomic shifts, resulting in the emerging of different sets of biotransformation pathways over different temperature ranges.

Biopolymer-based beads for the adsorptive removal of organic pollutants from wastewater: Current state and future perspectives

Among biopolymer-based adsorbents, composites in the form of beads have shown promising results in terms of high adsorption capacity and ease of separation from the effluents. This review addresses the potential of biopolymer-based beads to remediate wastewaters polluted with emerging organic contaminants, for instance dyes, active pharmaceutical ingredients, pesticides, phenols, oils, polyaromatic hydrocarbons, and polychlorinated biphenyls. High adsorption capacities up to 2541.76 mg g-1 for dyes, 392 mg g-1 for pesticides and phenols, 1890.3 mg g-1 for pharmaceuticals, and 537 g g-1 for oils and organic solvents have been reported. The review also attempted to convey to its readers the significance of wastewater treatment through adsorption by providing an overview on decontamination technologies of organic water contaminants. Various preparation methods of biopolymer-based gel beads and adsorption mechanisms involved in the process of decontamination have been summarized and analyzed. Therefore, we believe there is an urge to discuss the current state of the application of biopolymer-based gel beads for the adsorption of organic pollutants from wastewater and future perspectives in this regard since it is imperative to treat wastewater before releasing into freshwater bodies.

Detection of 13 emerging soil pollutant compounds using a dual extraction method (QuEChERS and solid phase extraction) and a liquid chromatography/mass spectrometry LC-MS/MS method

Emerging pollutants derived from human and animal sources, are present in soils and pose significant environmental and health impacts, even at low concentrations. Their detection in soil is analytically complex due to soil interference and the rapid degradation of compounds in the matrix. In this study, a protocol was optimized for quantifying hormonal steroids (n = 7), human drugs (n = 3), and antibiotics (n = 3) by a dual-phase extraction using QuEChERS and Solid Phase Extraction (SPE), followed by analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The double extraction phase allows an accurate and effective purification of the target compounds while eliminating the interference in the soil matrix. The method is optimized to detect environmental concentrations of these pollutants, to suit large-scale sampling campaigns and to maintain the efficiency of extraction while reducing analysis time. The limits of detection (LODs) of these compounds ranged between 0.0043 and 0.13 ng/g and recovery rates between 75.9 % and 105.39 %.•Enhanced Analyte Purification: Implements QuEChERS and SPE for robust removal of matrix interferences, optimizing target compound isolation.•Precision at Trace Levels: Secures LODs as minimal as 0.0043 ng/g, enabling accurate detection of low-concentration contaminants.•Adapted for Broad-scale sampling: Modifies extraction and analysis durations to accommodate large-scale environmental assessments.

Fate of contaminants of emerging concern in two wastewater treatment plants after retrofitting tertiary treatment for reduction of nitrogen discharge

More and more previously designed wastewater treatment plants (WWTPs) are upgraded to tertiary treatment to meet the higher effluent discharge standards of conventional pollutants. Contaminants of emerging concern (CECs) can cause adverse effects on organisms and usually flow into WWTPs along with urban sewage. How the retrofitted WWTPs targeting conventional pollutants will influence the treatment efficiency of CECs is seldom discussed. This study investigates the removal of CECs in two full-scale newly retrofitted WWTPs (CD and JM WWTPs), containing high-efficiency sedimentation tank and denitrification deep bed filter for enhancing total nitrogen removal. The overall CEC removal efficiencies in the CD and JM WWTPs were 73.79 % and 93.63 %, respectively. Mass balance results indicated that CD WWTP and JM WWTP release a total of 36.89 and 88.58 g/d of CECs into the environment through effluent and excess sludge, respectively. Analysis of the concentration of CECs along the treatment process revealed most CECs were removed in the biological treatment units. The incorporation of newly constructed tertiary treatment proved beneficial for CEC removal and removed 2.93 % and 2.36 % CECs, corresponding to CEC removal of 2.92 and 27.49 g/d in the CD and JM WWTPs, respectively. The data of this study were further used to evaluate the suitability of the SimpleTreat model for simulating the fate of CECs in WWTPs. The predicted fraction of CECs discharged through the biological treatment effluent were generally within ten-fold difference from the measured results, highlighting its potential for estimating CEC removal in WWTPs.

Snapshot Sampling May Not Be Enough to Obtain Robust Estimates for Riverine Microplastic Loads

Wastewater treatment plants (WWTPs) have been described as key contributors of microplastics (MPs) to aquatic systems, yet temporal fluctuations in MP concentrations and loads downstream are underexplored. This study investigated how different sampling frequencies (hourly, weekly, and monthly) affect MP estimates in a stream linked to a single WWTP. Utilizing fluorescence microscopy and Raman spectroscopy, considerable hourly variations in MP concentrations were discovered, while the polymer composition remained consistent. This temporal variability in MP loads was influenced by MP concentration, discharge rates, or a mix of both. These results show a high uncertainty, as relying on sparse snapshot samples combined with annual discharge data led to significant uncertainties in MP load estimates (over- and/or underestimation of emissions by 3.8 billion MPs annually at this site). Our findings stress the necessity of higher-frequency sampling for better comprehending the hydrodynamic factors influencing MP transport. This improved understanding enables a more accurate quantification of MP dynamics, crucial for downstream impact assessments. Therefore, preliminary reconnaissance campaigns are essential for designing extended, representative site-monitoring programs and ensuring more precise trend predictions on a larger scale.

Occurrence and fate of pharmaceuticals and personal care products in a wastewater treatment plant with Bacillus bio-reactor treatment

Pharmaceuticals and personal care products (PPCPs) have attracted wide attention due to their environmental impacts and health risks. PPCPs released through wastewater treatment plants (WWTPs) are estimated to be 80 %. Nevertheless, the occurrence of PPCPs in the WWTPs equipped with Bacillus spec.-based bioreactors (BBR) treatment system remains unclear. In this study, sludge and waste water samples were collected during separate winter and summer sampling campaigns from a typical BBR treatment system. The results indicate that out of 58 target PPCPs, 27 compounds were detected in the waste water (0.06-1900 ng/L), and 23 were found in the sludge (0.6-7755 ng/g dw). Paraxanthine was the chemical of the highest abundance in the influent due to the high consumption of the parent compounds caffeine and theobromine. The profile for PPCPs in the wastewater and sludge exhibited no seasonal variation. Overall, the removal of target PPCPs in summer is more effective than the winter. In the BBR bio-reactor, it was found that selected PPCPs (at ng/L level) can be completely removed. The efficiency for individual PPCP removal was increased from 1.0 % to 50 % in this unit, after target specific adjustments of the process. The effective removal of selected PPCPs by the BBR treatment system is explained by combined sorption and biodegradation processing. The re-occurrence of PPCPs in the wastewater was monitored. Negative removal efficiency was explained by the cleavage of Phase II metabolites after the biotransformation process, and the lack of equilibrium for PPCPs in the sludge of the second clarifier. A compound specific risk quotient (RQ) was calculated and applied for studying the potential environmental risks. Diphenhydramine is found with the highest environmental risk in wastewater, and 15 other PPCPs show negligible risks in sewage sludge.

A comparative study on performance of the conventional and fixed-bed membrane bioreactors for treatment of Naproxen from pharmaceutical wastewater

Here, a comparative study was designed to survey the treatment efficiency of pharmaceutical wastewater containing Naproxen by Membrane bioreactor (MBR) and MBR with fixed-bed packing media (FBMBR). To this end, the performance of MBR and FBMBR in different aeration conditions including average DO (1.9-3.8 mg/L), different organic loading (OLR) (0.86, 1.14 and 1.92 kg COD per cubic meter per day), and Naproxen removal efficiency. The BOD5 removal efficiency, effluent quality and membrane fouling were monitored within 140 days. The results obtained from the present study indicated that COD removal efficiency for FBMBR (96.46%) was higher than that for MBR (95.33%). In addition, a high COD removal efficiency was experienced in both MBR and FBMBR in operational conditions 3 and 4, even where OLR increased from 1.14 to 1.92 kgCOD/m3 d and DO decreased from 4 to < 1 mg/L. Furthermore, the higher Naproxen removal efficiency was observed in FBMBR (94.17%) compared to that for MBR (92.76%). Therefore, FBMBR is a feasible and promising method for efficient treatment of pharmaceuptical wastewater with high concentrations of emerging contaminant, especially, the Naproxen.

Biotransformation activities of fungal strain apiotrichum sp. IB-1 to ibuprofen and naproxen

Ibuprofen (IBU) and naproxen (NPX), as widely prescribed non-steroidal anti-inflammatory drugs (NSAIDs), are largely produced and consumed globally, leading to frequent and ubiquitous detection in various aqueous environments. Previously, the microbial transformation of them has been given a little attention, especially with the isolated fungus. A yeast-like Apiotrichum sp. IB-1 has been isolated and identified, which could simultaneously transform IBU (5 mg/L) and NPX (2.5 mg/L) with maximum efficiencies of 95.77% and 88.31%, respectively. For mono-substrate, the transformation efficiency of IB-1 was comparable to that of co-removal conditions, higher than most of isolates so far. IBU was oxidized mainly through hydroxylation (m/z of 221, 253) and NPX was detoxified mainly via demethylation (m/z of 215) as shown by UPLC-MS/MS results. Based on transcriptome analysis, the addition of IBU stimulated the basic metabolism like TCA cycle. The transporters and respiration related genes were also up-regulated accompanied with higher expression of several dehydrogenase, carboxylesterase, dioxygenase and oxidoreductase encoding genes, which may be involved in the transformation of IBU. The main functional genes responsible for IBU and NPX transformation for IB-1 should be similar in view of previous studies, which needs further confirmation. This fungus would be useful for potential bioremediation of NSAIDs pollution and accelerate the discovery of functional oxidative genes and enzymes different from those of bacteria.

Potential of hospital wastewater treatment using locally isolated Chlorella sp. LH2 from cocoon wastewater

Chlorella sp. is able to grow and transform inorganic and organic contaminants in wastewater to create biomass. In the present study, Chlorella sp. LH2 isolated from cocoon wastewater was able to thrive in hospital wastewater, then remove nutrients and eliminate E. coli ATCC 8739. The results indicated that optimal cultivation conditions of Chlorella sp. LH2 in hospital wastewater were pH of 8, light:dark cycle of 16:8 at 30oC. The inhibitory effect of chlorination on algae growth was accompanied with the chlorine concentration. BOD5:COD ratio of 0.77 indicated biodegradability of hospital wastewater. The untreated and treated wastewatee samples were collected to investigated the nutrient removal efficiency after 10 days. Untreated and treated results were192 ± 8.62 mg/l 23.91 ± 2.19 mg/l for BOD5; 245 ± 9.15 mg/l and 47.31 ± 5.71 mg/l for COD. The treated value met the required standards for hospital wastewater treatment. The removal efficiency total nitrogen and total phosphorus were 68.64% and 64.44% after 10 days, respectively. Elimination of E. coli ATCC 8739 after 7 days by Chlorella sp. LH2 was 88.92%. The results of this study suggest the nutrients and pathogens removal potential of Chlorella sp. LH2 in hospital wastewater for further practical applications.

Heterogeneous Antibiotic Resistance Gene Removal Impedes Evaluation of Constructed Wetlands for Effective Greywater Treatment

Microorganisms carrying antimicrobial resistance genes are often found in greywater. As the reuse of greywater becomes increasingly needed, it is imperative to determine how greywater treatment impacts antimicrobial resistance genes (ARGs). Using qPCR and SmartChip™ qPCR, we characterized ARG patterns in greywater microbial communities before, during, and after treatment by a recirculating vertical flow constructed wetland. In parallel, we examined the impact of greywater-treated irrigation on soil, including the occurrence of emerging micropollutants and the taxonomic and ARG compositions of microbial communities. Most ARGs in raw greywater are removed efficiently during the winter season, while some ARGs in the effluents increase in summer. SmartChip™ qPCR revealed the presence of ARGs, such as tetracycline and beta-lactam resistance genes, in both raw and treated greywater, but most abundantly in the filter bed. It also showed that aminoglycoside and vancomycin gene abundances significantly increased after treatment. In the irrigated soil, the type of water (potable or treated greywater) had no specific impact on the total bacterial abundance (16S rRNA gene). No overlapping ARGs were found between treated greywater and greywater-irrigated soil. This study indicates ARG abundance and richness increased after treatment, possibly due to the concentration effects of the filter beds.

Occurrence and fate of CECs (OMPs, ARGs and pathogens) during decentralised treatment of black water and grey water

Decentralised wastewater treatment is becoming a suitable strategy to reduce cost and environmental impact. In this research, the performance of two technologies treating black water (BW) and grey water (GW) fractions of urban sewage is carried out in a decentralised treatment of the wastewater produced in three office buildings. An Anaerobic Membrane Bioreactor (AnMBR) treating BW and a Hybrid preanoxic Membrane Bioreactor (H-MBR) containing small plastic carrier elements, treating GW were operated at pilot scale. Their potential on reducing the release of contaminants of emerging concern (CECs) such as Organic Micropollutants (OMPs), Antibiotic Resistance Genes (ARGs) and pathogens was studied. After 226 d of operation, a stable operation was achieved in both systems: the AnMBR removed 92.4 ± 2.5 % of influent COD, and H-MBR removed 89.7 ± 3.5 %. Regarding OMPs, the profile of compounds differed between BW and GW, being BW the matrix with more compounds detected at higher concentrations (up to μg L-1). For example, in the case of ibuprofen the concentrations in BW were 23.63 ± 3.97 μg L-1, 3 orders of magnitude higher than those detected in GW. The most abundant ARGs were sulfonamide resistant genes (sul1) and integron class 1 (intl1) in both BW and GW. Pathogenic bacteria counts were reduced between 1 and 3 log units in the AnMBR. Bacterial loads in GW were much lower than in BW, being no bacterial re-growth observed for the GW effluents after treatment in the H-MBR. None of the selected enteric viruses was detected in GW treatment line.

A thorough analysis of the occurrence, removal and environmental risks of organic micropollutants in a full-scale hybrid membrane bioreactor fed by hospital wastewater

The Urban Wastewater Treatment Directive recent draft issued last October 2022 pays attention to contaminants of emerging concern including organic micropollutants (OMPs) and requires the removal of some of them at large urban wastewater treatment plants (WWTPs) calling for their upgrading. Many investigations to date have reported the occurrence of a vast group of OMPs in the influent and many technologies have been tested for their removal at a lab- or pilot-scale. Moreover, it is well-known that hospital wastewater (HWW) contains specific OMPs at high concentration and therefore its management and treatment deserves attention. In this study, a 1-year investigation was carried out at a full-scale membrane bioreactor (MBR) treating mainly HWW. To promote the removal of OMPs, powdered activated carbon (PAC) was added to the bioreactor at 0.1 g/L and 0.2 g/L which resulted in the MBR operating as a hybrid MBR. Its performance was tested for 232 target and 90 non-target OMPs, analyzed by UHPLC-QTOF-MS using a direct injection method. A new methodology was defined to select the key compounds in order to evaluate the performance of the treatments. It was based on their frequency, occurrence, persistence to removal, bioaccumulation and toxicity. Finally, an environmental risk assessment of the OMP residues was conducted by means of the risk quotient approach. The results indicate that PAC addition increased the removal of most of the key OMPs (e.g., sulfamethoxazole, diclofenac, lidocaine) and OMP classes (e.g., antibiotics, psychiatric drugs and stimulants) with the highest loads in the WWTP influent. The hybrid MBR also reduced the risk in the receiving water as the PAC dosage increased mainly for spiramycin, lorazepam, oleandomycin. Finally, uncertainties and issues related to the investigation being carried out at full-scale under real conditions are discussed.

The predictive machine learning model of a hydrated inverse vulcanized copolymer for effective mercury sequestration from wastewater

Inverse vulcanized polysulfides (IVP) are promising sulfur-enriched copolymers with unconventional properties irresistible for diverse applications like Hg2+ remediation. Nevertheless, due to their inherent hydrophobic nature, these copolymers still offer low Hg2+ uptake capacity. Herein, we reported the synthesis of IVP by reacting molten sulfur with 4-vinyl benzyl chloride, followed by their functionalization using N-methyl D-glucamine (NMDG) to increase the hydration of the developed IVP. The chemical composition and structure of the functionalized IVP were proposed based on FTIR and XPS analysis. The functionalized IVP demonstrated a high mercury adsorption capacity of 608 mg/g (compared to <26 mg/g for common IVP) because of rich sulfur and hydrophilic regions. NMDG functionalized IVP removed 100 % Hg2+ from a low feed concentration (10-50 mg/l). A predictive machine learning model was also developed to predict the amount of mercury removed (%) using GPR, ANN, Decision Tree, and SVM algorithms. Hyperparameter and loss function optimization was also carried out to reduce the prediction error. The optimized GPR algorithm demonstrated high R2 (0.99 (training) and 0.98 (unseen)) and low RMSE (2.74 (training) and 2.53 (unseen)) values indicating its goodness in predicting the amount of mercury removed. The produced functionalized IVP can be regenerated and reused with constant Hg2+ uptake capacity. Sulfur is the waste of the petrochemical industry and is abundantly available, making the functionalized IVP a sustainable and cheap adsorbent that can be produced for high-volume Hg2+ remediation. ENVIRONMENTAL IMPLICATION: This research effectively addresses the removal of the global top-priority neurotoxic pollutant mercury, which is toxic even at low concentrations. We attempted to remove the Hg2+ utilizing an inexpensive adsorbent developed by NMDG functionalized copolymer of molten sulfur and VBC. A predictive machine learning model was also formulated to predict the amount of mercury removal from wastewater with only a 0.05 % error which shows the goodness of the developed model. This work is critical in utilizing this low-cost adsorbent and demonstrates its potential for large-scale industrial application.

Bandgap engineering approach for synthesising photoactive novel Ag/HAp/SnS2 for removing toxic anti-fungal pharmaceutical from aqueous environment

The present work shed light on synthesising a novel ternary Z-scheme Ag/HAp/SnS2 (AHS) nano photocatalyst to degrade metronidazole (MTZ) in wastewater through H2O2-assisted AOP under natural sunlight. HAp extracted from the fish scales of rohu fish through alkaline treatment was decorated with Ag nanoparticles using ascorbic acid as a bio-reductant. Tin disulphide (SnS2) was anchored over Ag/HAp to prevent agglomeration and enhance photocatalytic activity by delaying the electron-hole recombination rate. After 45 min of irradiation, a degradation efficiency of 98.85 ± 1.86% for 15 ppm MTZ could be achieved. The performance of the prepared photocatalyst in real wastewater was investigated by introducing several metal cations and anions in the photodegradation process. The degradation products were identified by HRLCMS analysis, and the breakdown mechanism of MTZ was proposed. The present study enlightens the importance of SnS2-based photocatalysts for organic pollutant degradation under natural sunlight through an advanced oxidation process. The characterization results showed that the enhanced photodegradation efficiency of AHS is attributed to the formation of an all-solid-state Z-scheme heterojunction with Ag nanoparticles acting as charge transfer medium and as electron accumulators helping in delaying charge recombination.

Assessing the Ecotoxicity of Eight Widely Used Antibiotics on River Microbial Communities

Global prevalence of antibiotic residues (ABX) in rivers requires ecotoxicological impact assessment. River microbial communities serve as effective bioindicators for this purpose. We quantified the effects of eight commonly used ABXs on a freshwater river microbial community using Biolog EcoPlates™, enabling the assessment of growth and physiological profile changes. Microbial community characterization involved 16S rRNA gene sequencing. The river community structure was representative of aquatic ecosystems, with the prevalence of Cyanobacteria, Proteobacteria, Actinobacteria, and Bacteroidetes. Our findings reveal that all ABXs at 100 µg/mL reduced microbial community growth and metabolic capacity, particularly for polymers, carbohydrates, carboxylic, and ketonic acids. Chloramphenicol, erythromycin, and gentamicin exhibited the highest toxicity, with chloramphenicol notably impairing the metabolism of all studied metabolite groups. At lower concentrations (1 µg/mL), some ABXs slightly enhanced growth and the capacity to metabolize substrates, such as carbohydrates, carboxylic, and ketonic acids, and amines, except for amoxicillin, which decreased the metabolic capacity across all metabolites. We explored potential correlations between physicochemical parameters and drug mechanisms to understand drug bioavailability. Acute toxicity effects at the river-detected low concentrations (ng/L) are unlikely. However, they may disrupt microbial communities in aquatic ecosystems. The utilization of a wide array of genetically characterized microbial communities, as opposed to a single species, enables a better understanding of the impact of ABXs on complex river ecosystems.

Study of the presence and environmental risk of organic contaminants policed by the European Union and other organic compounds in the water resources of a region overlapping protected areas: The Guadiaro River basin (southern Spain)

The study presented here is a first qualitative assessment of the occurrence of organic contaminants contemplated and not yet contemplated in European Union environmental legislation in water resources in the little anthropized Guadiaro River basin (70% of its area is covered by natural vegetation), in southern Spain. Water samples were collected from four carbonate aquifers, two detrital aquifers and four surface water courses and were analyzed for (i) 171 organic contaminants, (ii) major ions and (iii) stable isotopes (δ18OH2O, δ2HH2O, δ13CDIC). An environmental risk assessment was conducted through calculation of risk quotients comparing measured concentrations with ecotoxicological data found in the literature. Twenty-five organic contaminants were detected, at least once, including pesticides, pharmaceuticals, drugs of abuse and polycyclic aromatic hydrocarbons (PAHs). Cocaine and its main metabolite were detected in 85% and 95% of water samples, respectively (0.001-0.18 μg/L and 0.004-0.6 μg/L, respectively). Pyrene (PAH) was found in all water samples (0.001-0.015 μg/L) and forest fires were pointed out as a potential diffuse source. Relationship between rivers and aquifers is reflected by the distribution of organic contaminants, essentially the drugs of abuse. Concentration of contaminants were generally higher in groundwater samples, especially from detrital aquifers, potentially due to an accumulation process promoted by irrigation-return flows and by its slow dynamic compared to that of karstic systems. Pyrene concentration was also higher in some springs from karstic aquifers. Hence, calculated risk quotients were in general higher in groundwater, meaning that the threat to surface aquatic systems can grow as aquifers increase their influence on the water courses as the dry season progresses. The relationship between δ13CDIC and most organic contaminants (especially pyrene) reveal the role of the soil as storage media.

Acute and subchronic effects of ibuprofen on the ten spotted live-bearer fish Cnesterodon decemmaculatus (Jenyns, 1842)

Ibuprofen (IBP) is an anti-inflammatory drug found in aquatic environments, potentially toxic for the biota. We exposed the test fish C. decemmaculatus to two environmentally relevant concentrations (50 and 100 μg IBP/L) for 4 and 12 d and evaluated the effect on some biomarkers. Micronucleus test, nuclear abnormality test and comet assay indicated cyto-genotoxicity at both concentrations and exposure periods. Oxidative stress and biochemical biomarkers were not affected, excepting muscle AChE activity for 4 d. Muscle metabolic biomarkers showed significant decrease in ETS, lipid and protein content, while carbohydrate content was not affected. The CEA index increased at the lower IBP concentration for 4 and 12 d, possibly due to changes in body energy reserves. A full-factorial GLM performed to assess the effects of IBP and exposure times showed that the metabolic and genotoxicity biomarkers were the most sensitive to IBP toxicity, mainly at 50 μg IBP/L for 4 d.

Insights into effects of operating temperature on the removal of pharmaceuticals/pesticides/synthetic organic compounds by membrane bioreactor process

In this study, the removal efficiency and mechanism of 8 kinds of typical micropollutants by membrane bioreactor (MBR) at different temperatures (i.e. 15, 25 and 35 °C) were investigated. MBR exhibited the high removal rate (>85%) for 3 kinds of industrial synthetic organic micropollutants (i.e. bisphenol A (BPA), 4-tert-octylphenol (TB) and 4-n-nonylphenol (NP)) with similar functional groups, structures and high hydrophobicity (Log D > 3.2). However, the removal rates of ibuprofen (IBU), carbamazepine (CBZ) and sulfamethoxazole (SMX) with pharmaceutical activity showed great discrepancy (i.e. 93%, 14.2% and 29%, respectively), while that of pesticides (i.e. acetochlor (Ac) and 2,4-dichlorophenoxy acetic acid (2,4-D) were both lower than 10%. The results showed that the operating temperature played a significant role in microbial growth and activities. High temperature (35 °C) led to a decreased removal efficiency for most of hydrophobic organic micropollutants, and was also not conducive for refractory CBZ due to the temperature sensitivity. At lower temperature (15 °C), a large amount of exopolysaccharides and proteins were released by microorganisms, which caused the inhibited microbial activity, poor flocculation and sedimentation, resulting in the polysaccharide-type membrane fouling. It was proved that dominant microbial degradation of 61.01%-92.73% and auxiliary adsorption of 5.29%-28.30% were the main mechanisms for micropollutant removal in MBR system except for pesticides due to the toxicity. Therefore, the removal rates of most micropollutants were highest at 25 °C due to the high activity sludge so as to enhance microbial adsorption and degradation.

Predicting the removal efficiency of pharmaceutical and personal care products using heated metal oxides as adsorbents based on their physicochemical characteristics

Pharmaceutical and personal care products (PPCPs) are emerging pollutants that are commonly found in the environment and exist predominantly in nondegradable forms. Several attempts have been made to remove PPCPs via conventional wastewater treatment processes; however, these processes have limitations, such as high costs and insufficient removal efficiencies. Adsorption is a promising alternative for removing PPCPs because it is inexpensive, highly reusable, and easy to operate. Therefore, this study aims to determine the contributing characteristics that can be used to predict the adsorption behaviour of PPCPs based on their physicochemical properties, with heated metal oxide adsorbents (HMOAs). HAOP (heated aluminium oxide particles) and HIOP (heated iron oxide particles) with particle sizes below 38 μm were used. Results from the Brunauer-Emmett-Teller (BET) analysis show that HIOP has higher surface area and smaller pore size (113.7 ± 26.3 m2/g and 5.4 ± 1.8 nm) than HAOP (14.5 ± 0.6 m2/g and 18.6 ± 3.1 nm), which suggest that HIOP would show superior adsorption rates compared to HAOP. The adsorption mechanism is identified based on three major physicochemical properties of PPCPs: molecular weight (M.W.), octanol-water partition coefficient (log Kow), and acid dissociation constant (pKa). The results suggest that the most dominant factor that contributes to the adsorption of PPCPs on to HMOAs is the M.W., where the larger the molecular size, the better the adsorption efficiency. The tests conducted with varying log Kow values revealed that the hydrophilicity of the adsorbent influences the adsorption performance. It was found that HIOP exhibits better removal efficiencies with hydrophilic PPCPs (up to 83%) than with hydrophobic PPCPs (48%), while HAOP exhibits better removal efficiencies with hydrophobic PPCPs (86%) than with hydrophilic PPCPs, with less than 10% removal. Unlike the M.W. and pKa values, the log Kow does not exhibit any visible trend. Therefore, the adsorption behaviour can be predicted with the M.W. and pKa values of the PPCPs, when HAOP and HIOP are used as adsorbents.

The key constituents underlying the combined toxicity of eight cosmetic contaminants towards Vibrio qinghaiensis

Cosmetic additives (ADDs) and packaging plasticizers (PLAs) probably present potential risks and dangers to the environment and human body as emerging pollutants. To investigate their potential risks and dangers, five ADDs including methyl paraben (MET), ethyl paraben (ETH), propyl paraben (PRO), butyl-hydroxy anisole (BHA), and salicylic acid (SAL), as well as three PLAs including bisphenol A (BPA), bisphenol S (BPS) and tris(2-butoxyethyl) phosphate (TBEP) were selected as research objects, and ten mixture rays (R1-R10) composed of the eight components were designed by the uniform design ray (UD-Ray) method. The toxicities of the eight cosmetic pollutants and their eight-component mixture system towards Vibrio qinghaiensis sp.-Q67 (Q67) were systematically determined by the time-dependent microplate toxicity analysis (t-MTA) method. The three-dimensional (3D) surface of deviation from the concentration addition model (dCA) was utilized to qualitatively and quantitatively analyse the toxicity interaction of the mixtures and the correlation between toxicity interaction and the components' concentration ratios. Finally, eight individual pollutants and representative rays with significant inhibitory and interactive effects were selected to analyse DNA and soluble proteolysis as well as the microstructure and morphology of Q67 after treatment with single chemicals and their mixtures. The results showed that the eight cosmetic pollutants had conspicuous concentration-dependent toxicity and acute toxicity, and none of them, except BPS, BPA and ETH, had time-dependent toxicity. All rays had time/concentration-dependent toxicity and acute toxicity. At the same time, the toxicity interaction of these mixture rays was predominantly antagonism and the strongest antagonism appeared at high concentrations at 12 h. Nevertheless, the components' concentration ratio (pi) was the decisive factor for the type of mixture interaction. The correlation analysis revealed a significant positive linear correlation between mixture toxicity and pETH and pBPA, which indicated that ETH and BPA were the key components of the toxic effects. However, there was a significant negative linear correlation between the antagonism intensity and pBPA and pTBEP, which demonstrated that BPA and TBEP were the key components of the antagonism intensity. Pollutants and their mixtures can also damage cellular structures, and mixtures can exacerbate the dissolution of DNA and soluble proteins.

Fate of emerging contaminants in a sequencing batch reactor and potential of biological activated carbon as tertiary treatment for the removal of persisting contaminants

The study aims to understand the occurrence and removal of 20 emerging contaminants (ECs) in each unit process of a sequencing batch reactor-based wastewater treatment plant (WWTP) and explore the potential of biological activated carbon (BAC) for the treatment of residual ECs and organic matter in the secondary effluent. Analgesic-acetaminophen, anti-inflammatory drug-ibuprofen, and stimulant-caffeine were detected at high concentrations in the influent. Most of the removal was observed in the biological treatment stage in the SBR basins. The mass load of the ECs was 2.93 g/d in the secondary effluent and 0.4 g/d in the final sludge, while the total removal of the mass load of ECs till the secondary treatment stage was 93.22%. 12 of the 20 ECs were removed by more than 50%, while carbamazepine (negative removal), sulfamethoxazole, and trimethoprim were removed by less than 20%. As a polishing step and to remove residual ECs, two BAC units were studied for 11,000 bed volumes (324 days). Packed column studies on granular activated carbon were conducted, and GAC development to BAC was monitored. SEM and FTIR were used to confirm and characterize the BAC. The BAC appeared to be more hydrophobic than the GAC. The BAC removed 78.4% and 40% of the dissolved ECs and organic carbon at an optimum EBCT of 25 min. Carbamazepine, sulfamethoxazole, and trimethoprim were removed by 61.5, 84, and 52.2%, respectively. Parallel column tests revealed adsorption as an important mechanism for the removal of positively charged compounds. The results indicate that the BAC is an effective tertiary/polishing technique for removing organic and micropollutants in the secondary wastewater effluent.

SBBGR technology for reducing waste sludge production during plastic recycling process: Assessment of potential increase in sludge hazardousness

Sludge production in the wastewater treatment sector is consistently increasing and represents a critical environmental and economic issue. This study evaluated an unconventional approach for treating wastewater generated from the cleaning of non-hazardous plastic solid waste during the plastic recycling process. The proposed scheme was based on sequencing batch biofilter granular reactor (SBBGR) technology, which was compared with the activated sludge-based treatment currently in operation. These treatment technologies were compared regarding sludge quality, specific sludge production, and effluent quality to highlight whether the reduced sludge production shown by SBBGR corresponded to an increase in the concentration of hazardous compounds in the sludge. The SBBGR technology showed remarkable removal efficiencies (TSS, VSS, and NH₃ > 99 %; COD >90 %; TN and TP > 80 %) and a sludge production six-fold lower than the conventional plant (in terms of kgTSS/kg COD_removed). Biomass from the SBBGR did not show a significant accumulation of organic micropollutants (i.e., long-chain hydrocarbons, chlorinated pesticides and chlorobenzenes, PCB, PCDD/F, PAH, chlorinated and brominated aliphatic compounds, and aromatic solvents), whereas a certain accumulation of heavy metals was observed. Furthermore, an initial attempt to compare the operating costs of the two treatment approaches revealed that the SBBGR technology would provide 38 % savings.

Biosorption and biotransformation behaviours of veterinary antibiotics under aerobic livestock wastewater treatment processes

To study the fate of veterinary antibiotics released from swine wastewater treatment plants (SWTP), 10 antibiotics were investigated in each unit of a local SWTP periodically. Over a 14-month period of field investigation into target antibiotics, it was confirmed that tetracycline, chlortetracycline, sulfathiazole, and lincomycin were used in this SWTP, with their presence observed in raw manure. Most of these antibiotics could be effectively treated by aerobic activated sludge, except for lincomycin, which was still detected in the effluent, with a maximum concentration of 1506 μg/L. In addition, the potential for removing antibiotics was evaluated using lab-scale aerobic sequencing batch reactors (SBRs) that were dosed with high concentrations of antibiotics. The SBR results, however, showed that both sulfonamides and macrolides, as well as lincomycin, can achieve 100% removal in lab-scale aerobic SBRs within 7 days. This reveals that the potential removal of those antibiotics in field aeration tanks can be facilitated by providing suitable conditions, such as adequate dissolved oxygen, pH, and retention time. Furthermore, the biosorption of target antibiotics was also confirmed in the abiotic sorption batch tests. Biotransformation and hydrolysis were identified as the dominant mechanism for removing negatively charged sulfonamides and positively charged antibiotics (macrolides and lincomycin) in SBRs. This is due to their relatively low sorption affinity (resulting in negligible to 20% removal) onto activated sludge in abiotic sorption tests. On the other hand, tetracyclines exhibited significant sorption behavior both onto activated sludge and onto soluble organic matters in swine wastewater supernatant, accounting for 70%-91% and 21%-94% of removal within 24 h, respectively. S-shape sorption isotherms with saturation were observed when high amounts of tetracyclines were spiked into sludge, with equilibrium concentrations ranging from 0.4 to 65 mg/L. Therefore, the sorption of tetracyclines onto activated sludge was governed by electrostatic interaction rather than hydrophobic partition. This resulted in a saturated sorption capacity (Q_max) of 17,263 mg/g, 1637 mg/g, and 641.7 mg/g for OTC, TC, and CTC, respectively.

Disinfection byproducts of iopamidol, iohexol, diatrizoate and their distinct acute toxicity on Scenedesmus sp., Daphnia magna and Danio rerio

The COVID-19 pandemic resulted in increasing the usage of iodinated contrast media (ICM), and thus an increase in the prevalence of ICM-contaminated wastewater. While ICM is generally safe, this has the potential to be problematic because as medical wastewater is treated and disinfected, various ICM-derived disinfection byproducts (DBPs) may be generated and released into the environment. However, little information was available about whether ICM-derived DBPs are toxic to aquatic organisms. In this study, the degradation of three typical ICM (iopamidol, iohexol, diatrizoate) at initial concentration of 10 μM and 100 μM in chlorination and peracetic acid without or with NH₄⁺ was investigated, and the potential acute toxicity of treated disinfected water containing potential ICM-derived DBPs on Daphnia magna, Scenedesmus sp. and Danio rerio was tested. The degradation results suggested that only iopamidol was significantly degraded (level of degradation >98%) by chlorination, and the degradation rate of iohexol and diatrizoate were significantly increased in chlorination with NH₄⁺. All three ICM were not degraded in peracetic acid. The toxicity analysis results indicate that only the disinfected water of iopamidol and iohexol by chlorination with NH₄⁺ were toxic to at least one aquatic organism. These results highlighted that the potential ecological risk of ICM-contained medical wastewater by chlorination with NH₄⁺ should not be neglected, and peracetic acid may be an environment-friendly alternative for the disinfection of wastewater containing ICM.

Insight into the adsorptive removal of ibuprofen using porous carbonaceous materials: A review

Over the last decade, the removal of pharmaceuticals from aquatic bodies has garnered substantial attention from the scientific community. Ibuprofen (IBP), a non-steroidal anti-inflammatory drug, is released into the environment in pharmaceutical waste as well as medical, hospital, and household effluents. Adsorption technology is a highly efficient approach to reduce the IBP in the aquatic environment, particularly at low IBP concentrations. Due to the exceptional surface properties of carbonaceous materials, they are considered ideal adsorbents for the IBP removal of, with high binding capacity. Given the importance of the topic, the adsorptive removal of IBP from effluent using various carbonaceous adsorbents, including activated carbon, biochar, graphene-based materials, and carbon nanostructures, has been compiled and critically reviewed. Furthermore, the adsorption behavior, binding mechanisms, the most effective parameters, thermodynamics, and regeneration methods as well as the cost analysis were comprehensively reviewed for modified and unmodified carbonaceous adsorbents. The compiled studies on the IBP adsorption shows that the IBP uptake of some carbon-based adsorbents is significantly than that of commercial activated carbons. In the future, much attention is needed for practical utilization and upscaling of the research findings to aid the management and sustainability of water resource.

Mass flow and consumption calculations of pharmaceuticals in sewage treatment plant with emphasis on the fate and risk quotient assessment

In Egypt, pharmaceuticals consumption increased dramatically owing to the population growth and the unrestricted sale manner. Accordingly, the occurrence and fate of nine common pharmaceutical active compounds (PhACs) were scrutinized at a sewage treatment plant (STP) in Giza, Egypt. The levels of these PhACs were assessed in different the wastewater treatment stages and dewatered sludge phase using high-performance liquid chromatography coupled with photodiode arrays detector. The average concentrations of the total PhACs detected in influent, primary sedimentation effluent (PSE) and final effluent (FE) were 227, 155 and 89 µg L^-1, respectively. The overall removal efficiency of the individual PhACs ranged from 18 to 72% removal. The occurrence trend revealed that biodegradation and adsorption are the concurrently removal mechanisms of the studied PhACs. The overall consumption per day in West of Greater Cairo was estimated based on influent concentration of STP. Sulfamethoxazole, paracetamol and diclofenac were detected with the highest levels in the influent of STP, PSE and FE as well as in the dewatered sludge. Furthermore, the high concentrations of these compounds in the sludge confirm the adsorption pathway removal of theses PhACs. The risk quotient (RQ) assessment for the detected PhACs in FE is greatly higher than the predicted non-effect concentration (PNEC). Conclusively, the FE of STP is considered a risky source for PhACs in adjacent surface water.

Remediation of phthalate acid esters from contaminated environment—Insights on the bioremedial approaches and future perspectives

Phthalates are well-known emerging pollutants that are toxic to the environment and human health. Phthalates are lipophilic chemicals used as plasticizers in many of the items for improving their material properties. These compounds are not chemically bound and are released to the surroundings directly. Phthalate acid esters (PAEs) are endocrine disruptors and can interfere with hormones, which can cause issues with development and reproduction, thus there is a huge concern over their existence in various ecological surroundings. The purpose of this review is to explore the occurrence, fate, and concentration of phthalates in various environmental matrices. This article also covers the phthalate degradation process, mechanism, and outcomes. Besides the conventional treatment technology, the paper also aims at the recent advancements in various physical, chemical, and biological approaches developed for phthalate degradation. In this paper, a special focus has been given on the diverse microbial entities and their bioremedial mechanisms executes the PAEs removal. Critically, the analyses method for determining intermediate products generated during phthalate biotransformation have been discussed. Concluisvely, the challenges, limitations, knowledge gaps and future opportunities of bioremediation and their significant role in ecology have also been highlighted.

Sorption of cosmetic and personal care polymer ingredients to iron oxides, clay minerals and soil clays: An environmental perspective

The increasing daily use of cosmetic and personal care ingredients (CPCIs) requires improved understanding of the fate and impacts of CPCIs in environmental systems. Effects of CPCIs on colloidal properties of various geocolloids such as iron oxides (goethite, haematite), clay minerals (kaolinite, bentonite) and soil clays (kaolinitic-, illitic- and lateritic soil clays) were studied by tracking time-resolved changes in zeta potential (ζ) and observing suspended particle density. Two polymers representing anionic CPCIs, i.e., polyacrylate crosspolymer-11 (PC11) and cationic CPCIs, i.e., polyDADMAC (PD) show contrast effects on ζ and colloidal properties of the selected materials. While PC11 tended to associate with Fe oxides, PD can be adsorbed by clay minerals and soil clays. The neutralization due to the sorption of either PC11 or PD onto opposite-charge sign surface sites can lower the net surface charge of the materials, thereby enhancing electrostatic attraction, stimulating particle size growth, and eventually intensifying co-aggregation. The observed colloidal properties of iron oxides, clay minerals and soil clays under the presence of PC11 and PD may reflect what are happening in many aquatic environments where CPCIs co-exist with various mineral colloids. Therein, CPCIs likely delay the transport of the opposite-charge sign colloids, while they increase the dispersibility and transportability of the same-charge sign colloids. This implies that intensifying presence of a given CPCI could have selective effects on colloid systems. As a whole, CPCIs can change the fate and the final destination of mineral colloids and themselves; therefore, their effects and relevant treatment techniques need to be included into the future agenda.

Public health implications of endocrine disrupting chemicals in drinking water and aquatic food resources in Nigeria: A state-of-the-science review

This state-of-the-science review is aimed at identifying the sources, occurrence, and concentrations of EDCs, including potential public health risks associated with drinking water and aquatic food resources from Nigerian inland waters. A total of 6024 articles from scientific databases (PubMed, Scopus, Web of science, ScienceDirect, Google Scholar, and African Journals Online) were identified, out of which, 103 eligible articles were selected for this study. Eleven (11) classes of EDCs (OCPs, PCBs, PBDEs, PAHs, BPA, OTs, PEs, PCs, PPCPs, sterols and n-alkanes) were identified from drinking waters, river sediments and aquatic food species from Nigerian rivers, showing that OCPs were the most studied and reported EDCs. Analytical methods used were HPLC, LC-MS/MS, GC-FID, GC-ECD and GC-MS with all EDCs identified to originate from anthropogenic sources. Carcinogenic, mutagenic, and teratogenic effects were the highest (54.4 %) toxicological effects identified, while reproductive/endocrine disruptive effects (15.2 %) and obesogenic effects (4.3 %) were the least identified toxicological effects. The targeted hazard quotient (THQ) and cancer risk (CR) were generally highest in children, compared to the adult populations, indicating age-specific toxicity. PEs produced the highest THQ (330.3) and CR (1.2) for all the EDCs in drinking water for the children population, suggesting enhanced vulnerability of this population group, compared to the adult population. Due to associated public health, wildlife and environmental risk of EDCs and their increasing concentrations in drinking water and food fish species from Nigerian inland waters, there is an urgent need for focused and strategic interventions, sensitization and policy formulation/implementation towards public health and aquatic food safety in Nigeria.

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.

Influence of metabolism and microbiology on organic micropollutants biotransformation in anoxic heterotrophic reactors

There is scarce information about the biotransformation of organic micropollutants (OMPs) under anoxic conditions. In this study, a heterotrophic denitrifying bioreactor was set up to study the fate of several OMPs from metabolic and microbiological points of view. Primary metabolic activity was increased by adding progressively higher nitrogen loading rates during the operation (from 0.075 to 0.4 g N-NO₃^- L^-1 d^-1), which resulted in an important shift in the microbial population from a specialized biomass to a more diverse community. Such a change provoked a significant increase in the removal efficiency of erythromycin (ERY), roxithromycin (ROX) and bisphenol-A (BPA), and some bacterial taxa, such as Rhodoplanes, were identified as possible indicators related to the biodegradation of these compounds. The increasing primary metabolic activity in the reactor did not enhance the OMP-specific removal rates, suggesting that the bacterial composition is more influential than cometabolism.

Complementarity of two approaches based on the use of high-resolution mass spectrometry for the determination of multi-class antibiotics in water. Photodegradation studies and non-target screenings

The development of analytical methodologies to monitor different antibiotic families in water and the implementation of alternatives for their efficient elimination are a great challenge. The aim of this research was to develop a method based on solid-phase extraction followed by ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry to analyse multi-class antibiotics, including macrolides, cephalosporins, fluoroquinolones, sulfonamides and diaminopyrimidines, in waters. Several parameters affecting the extraction such as the sample pH, type of sorbent and cartridge, elution volume and breakthrough volume were optimized. The method was validated in real samples, and matrix effect was assessed, demonstrating that the use of isotopically labelled surrogate compounds was mandatory to avoid standard addition calibration for each individual samples. Urban and hospital wastewater samples, as well as natural waters, were analysed, confirming the presence of 12 of the 14 target compounds at concentrations up to 3.5 µg L-1. Non-target analysis based on data-independent workflow was also performed, enabling the identification of 94 pollutants. Preliminary photodegradation experiments were also assessed, revealing the total removal of many target compounds after the first 5-10 min of UVC irradiation. In addition, 20 by-products formed after photolysis could be identified using a non-target approach.

Removal of Iodine-Containing X-ray Contrast Media from Environment: The Challenge of a Total Mineralization

Iodinated X-ray contrast media (ICM) as emerging micropollutants have attracted considerable attention in recent years due to their high detected concentration in water systems. It results in environmental issues partly due to the formation of toxic by-products during the disinfection process in water treatment. Consequently, various approaches have been investigated by researchers in order to achieve ICM total mineralization. This review discusses the different methods that have been used to degrade them, with special attention to the mineralization yield and to the nature of formed by-products. The problem of pollution by ICM is discussed in the first part dedicated to the presence of ICM in the environment and its consequences. In the second part, the processes for ICM treatment including biological treatment, advanced oxidation/reductive processes, and coupled processes are reviewed in detail. The main results and mechanisms involved in each approach are described, and by-products identified during the different treatments are listed. Moreover, based on their efficiency and their cost-effectiveness, the prospects and process developments of ICM treatment are discussed.

Screening of antimicrobials, fragrances, UV stabilizers, plasticizers and preservatives in sewage treatment plants (STPs) and their risk assessment in India

Community/industrial wastewater is the prime source of anthropogenic chemicals, its treatment is often a daunting task and unaffordable for many countries. Emerging Contaminants (ECs) have been drained into wastewater after continuous use/misuse and Conventional treatments in STPs do not remove them completely. ECs including antimicrobial agents, synthetic musks, Benzotriazole UV stabilizers (BUVSs), plasticizers, and preservatives are frequently reported in environment, and cause health effects to non-target organisms. Monitoring of ECs is important to understand their status in aquatic environment. Hence, it was aimed to monitor ECs (n = 21) from 11 STPs in Tamil Nadu, India. The detection frequency of most of these analytes was >90%. Antimicrobials ranged from 247 to 22,714 ng/L and 11-14,369 ng/L in influents and effluents, respectively. The synthetic musks were in the order of Tonalide > Galaxolide > Musk Ketone. BUVSs ranged from 4 to 1632 ng/L (influents) and < LOD to 29,853 ng/L (effluents). Concentration of phthalates in influents and effluents were < LOD - 11,311 ng/L and < LOD - 17,618 ng/L, respectively. Parabens were found in the order of Prophyl > Methyl > Ethyl > Butyl in influents and Methyl > Prophyl > Butyl > Ethyl in effluents. Mass loads of ECs through STPs were found as antimicrobials > plasticizers > fragrances > BUVSs > Preservatives. This study reveals increasing usage of ECs and inadequate treatment processes at STPs in India. Also helps to adopt suitable treatment processes to remove ECs from wastewater and to reuse the wastewater.

Assessing the Persistence and Mobility of Organic Substances to Protect Freshwater Resources

Persistent and mobile organic substances are those with the highest propensity to be widely distributed in groundwater and thereby, when emitted at low-levels, to contaminate drinking water extraction points and freshwater environments. To prevent such contamination, the European Commission is in the process of introducing new hazard classes for persistent, mobile, and toxic (PMT) and very persistent and very mobile (vPvM) substances within its key chemical regulations CLP and REACH. The assessment of persistence in these regulations will likely be based on simulated half-life, t _1/2, thresholds; the assessment of mobility will likely be based on organic carbon-water distribution coefficient, K _OC, thresholds. This study reviews the use of t _1/2 and K _OC to describe persistence and mobility, considering the theory, history, suitability, data limitations, estimation methods, and alternative parameters. For this purpose, t _1/2, K _OC, and alternative parameters were compiled for substances registered under REACH, known transformation products, and substances detected in wastewater treatment plant effluent, surface water, bank filtrate, groundwater, raw water, and drinking water. Experimental t _1/2 values were rare and only available for 2.2% of the 14 203 unique chemicals identified. K _OC data were only available for a fifth of the substances. Therefore, the usage of alternative screening parameters was investigated to predict t _1/2 and K _OC values, to assist weight-of-evidence based PMT/vPvM hazard assessments. Even when considering screening parameters, for 41% of substances, PMT/vPvM assessments could not be made due to data gaps; for 23% of substances, PMT/vPvM assessments were ambiguous. Further effort is needed to close these substantial data gaps. However, when data is available, the use of t _1/2 and K _OC is considered fit-for-purpose for defining PMT/vPvM thresholds. Using currently discussed threshold values, between 1.9 and 2.6% of REACH registered substances were identified as PMT/vPvM. Among the REACH registered substances detected in drinking water sources, 24-30% were PMT/vPvM substances.

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.

Critical review of technologies for the on-site treatment of hospital wastewater: From conventional to combined advanced processes

This review aims to assess different technologies for the on-site treatment of hospital wastewater (HWW) to remove pharmaceutical compounds (PhCs) as sustances of emerging concern at a bench, pilot, and full scales from 2014 to 2020. Moreover, a rough characterisation of hospital effluents is presented. The main detected PhCs are antibiotics and psychiatric drugs, with concentrations up to 1.1 mg/L. On the one hand, regarding the presented technologies, membrane bioreactors (MBRs) are a good alternative for treating HWW with PhCs removal values higher than 80% in removing analgesics, anti-inflammatories, cardiovascular drugs, and some antibiotics. Moreover, this system has been scaled up to the pilot plant scale. However, some target compounds are still present in the treated effluent, such as psychiatric and contrast media drugs and recalcitrant antibiotics (erythromycin and sulfamethoxazole). On the other hand, ozonation effectively removes antibiotics found in the HWW (>93%), and some studies are carried out at the pilot plant scale. Even though, some families, such as the X-ray contrast media, are recalcitrant to ozone. Other advanced oxidation processes (AOPs), such as Fenton-like or UV treatments, seem very effective for removing pharmaceuticals, Antibiotic Resistance Bacteria (ARBs) and Antibiotic Resistance Genes (ARGs). However, they are not implanted at pilot plant or full scale as they usually consider extra reactants such as ozone, iron, or UV-light, making the scale-up of the processes a challenging task to treat high-loading wastewater. Thus, several examples of biological wastewater treatment methods combined with AOPs have been proposed as the better strategy to treat HWW with high removal of PhCs (generally over 98%) and ARGs/ARBs (below the detection limit) and lower spending on reactants. However, it still requires further development and optimisation of the integrated processes.

Impact of eight widely consumed antibiotics on the growth and physiological profile of natural soil microbial communities

Antibiotics' (ATBs) occurrence in soil ecosystems has a relevant effect in the structure and functionality of edaphic microbial communities, mainly because of their amendment with manure and biosolids that alter their key ecological functions. In this study, the impact of eight widely consumed ATBs on a natural soil microbial community, characterized through 16 S rRNA gene sequencing, was evaluated. Changes induced by the ATBs in the growth of the soil microbiota and in the community-level physiological profiling (CLPP), using Biolog EcoPlates™, were measured as endpoint. The eight assayed ATBs lead to a significant decrease in the growth of soil microbial communities in a dose-dependent way, ordered by its effect as follows: chloramphenicol > gentamycin > erythromycin > ampicillin > penicillin > amoxicillin > tetracycline > streptomycin. Chloramphenicol, gentamycin, and erythromycin adversely affected the physiological profile of the soil community, especially its ability to metabolize amino acids, carboxylic and ketonic acids and polymers. The analysis of the relationship between the physico-chemical properties of ATBs, as well as their mechanism of action, revealed that, except for the aminoglycosides, each ATB is influenced by a different physico-chemical parameters, even for ATBs of the same family. Significant effects were detected from 100 μg mL to 1, concentrations that can be found in digested sludge, biosolids and even in fertilized soils after repeated application of manure, so cumulative and long-term effects of these antibiotics on soil environment cannot be ruled out.

Application of duckweed (Lemna sp.) and water fern (Azolla sp.) in the removal of pharmaceutical residues in water: State of art focus on antibiotics

In recent decades, antibiotic residues in the environment have increased, affecting components of biological communities, from bacteria to plants and animals. Different methods have been used to remove these compounds, including phytoremediation with floating aquatic species such as duckweed and aquatic fern, with positive results. This study analyses information about the removal efficiency of drugs, with a focus on antibiotics, using Lemna and Azolla, which will allow a better understanding of phytoremediation processes from the perspective of plant physiology. The physiological processes of macrophytes in an environment with this type of pollutant and the phytotoxic effects on plants at high concentrations are also analysed. The metabolization of toxic compounds occurs in three phases: phase I begins with the absorption of antibiotics and the secretion of reactive oxygen species (ROS); in phase II, the effects of ROS are neutralized and minimized by conjugation with enzymes such as glutathione transferase or metabolites such as glutathione; and phase III culminates with the storage of the assimilated compounds in the vacuoles, apoplast and cell wall. In this way, plants contribute to the removal of toxic compounds. In summary, there is sufficient scientific evidence on the efficiency of the elimination of pharmaceutical compounds by these floating macrophytes at the laboratory scale, which indicates that their application under real conditions can have good results.