Consolidated vs new advanced treatment methods for the removal of contaminants of emerging concern from urban wastewater

Performance of ultrafiltration-ozonation for municipal wastewater reclamation under rainstorm conditions: Impacts of DOM surge on micropollutant removal and associated risks

This study investigated the impacts of rainstorms on the performance of a combined ultrafiltration (UF)-ozonation (O3) process for micropollutant removal and risk mitigation during municipal wastewater reclamation. Results reveal that the rainstorm triggered a substantial surge in dissolved organic matter (DOM) in secondary effluent, primarily composed of protein-like substances and terrestrial humus. Meanwhile, 12 commonly detected pharmaceuticals and personal care products (PPCPs) were found at concentrations slightly lower than in normal weather, ranging from 5.0 to 545.0 ng L-1. Following the rainstorm, the overall removals of PPCPs spanned a wide range of 14.8 %-77.7 %, where a significantly lower retention of high molecular-weight pollutants (e.g., ≥ 400 Da) was observed for UF. For the ozonation unit, the removals remained comparable, while the relative contribution of radical oxidation increased. This shift was related to the enhanced generation of HO• and/or other reactive species, driven by the enrichment of unsaturated proteins (originating from upstream sludge loss) as precursors. Higher concentrations of disinfection by-products (DBPs), reaching up to 1372.5 μg L-1, were observed in chlorinated effluents after the rainstorm, ascribing to the elevated content of terrestrial humus persisting through the treatments. While the risks associated with PPCPs were negligible, the formed DBPs posed considerable risks to human health (with cancer risk at 10-5) and aquatic ecosystem (with risk quotient up to 13.6), particularly post ozonation. These findings highlight the role of rainstorm-fueled DOM in reclaimed water quality and provide insights into ensuring reclaimed water safety under different weather conditions.

Impact of the wastewater treatment technology and storage on micropollutant profiles during reclaimed water irrigation: A wide-scope HRMS screening in a water-soil-lettuce-leachate system

In recent decades, climate change and global warming have intensified water scarcity, while the growing global population demands have increased. Reclaimed water (RW) has become essential, offering a viable alternative for crop irrigation in line with circular economy principles. However, although RW reuse is crucial for addressing water shortages, the presence of micropollutants still poses a challenge. The potential for micropollutants to be taken up by crops and enter the food chain still raises significant scientific concern. This work studies RW treated by conventional activated sludge followed by sand filtration and chlorination (CAS+SFC-RW) and membrane-bioreactor-treated RW (MBR-RW) in terms of micropollutant concentrations, providing insights into the differences in micropollutant profiles between the two treatments. The results demonstrate that MBR-RW generally exhibits lower cumulative concentrations of target analytes. However, the study also indicates that the storage of RW for irrigation significantly affects the presence of micropollutants, contributing to their degradation, increase or persistence. Soil analysis revealed fewer detectable micropollutants in the topsoil (0-20 cm) compared to RW, likely attributed to attenuation processes, and more micropollutants (both with respect to concentration and number) compared to deeper soil layers. Carbamazepine, 10,11-epoxide-carbamazepine, and telmisartan were found to migrate to deeper soil levels. The analysis revealed 13 micropollutants in lettuce irrigated with CAS+SFC-RW and 8 with MBR-RW, with carbamazepine and sulfamethoxazole being the most abundant. These differences are likely driven by the physicochemical properties of the compounds and plant-specific factors. Leachates examination showed the potential for contaminants to leach through soil, posing a risk for groundwater contamination. The study showed that the presence of micropollutants in RW is not directly associated with their presence in soil or lettuce, underscoring the need for regulatory policies that address not only their presence in RW but their eventual fate within the agricultural and environmental context.

Responses of microbial community to the selection pressures of low-concentration contaminants of emerging concern in activated sludge

The activated sludge system used in wastewater treatment plants has demonstrated partial removal capabilities for various contaminants of emerging concern (CECs). However, existing research primarily focuses on the removal efficiency individual or combined CECs, with limited research addressing their impact on microbial community. In this study, three activated sludge systems were developed to investigate the effects of low concentrations of CECs, including five types of antibiotics and five types of non-antibiotic CECs. The results showed that activated sludge could effectively degrade non-antibiotic CECs within 3 -5 days even in the third cycle, whereas the degradation of antibiotics was more variable. Compared to the AA-Group, Alphaproteobacteria, Anaerolineae, Planctomycetes, Gammaproteobacteria, and Bacteroidia shifted to connector in the non-AA treatment as keystones species. Variance partitioning and co-occurrence network analysis showed that CECs exert significant deterministic influences, surpassing traditional environmental factors. Notably, antibiotics promoted microbial interactions more than other CECs, the finding was further validated by null model analysis. Our study provides novel insights into the differential impacts of low-concentration CECs on microbial community dynamics and interactions. Findings highlight the necessity to better understand the complex microbial processes driven by CECs, particularly antibiotics, to further develop more efficient biological treatment processes for CECs removal.

Effect of microplastics on tertiary/quaternary treatment of urban wastewater: Fe-biochar/peroxymonosulfate/sunlight vs solar photo-Fenton

Microplastics (MPs) are detected at various stages of urban wastewater treatment plants (UWTPs), however their impact on tertiary/quaternary treatments has been underexplored so far. This study evaluates the effect of MPs on the degradation of four micropollutants (carbamazepine, diclofenac, sulfamethoxazole, and trimethoprim) and the inactivation of total and antibiotic resistant (AR) E. coli in secondary treated urban wastewater (SUWW) through two advanced oxidation processes: iron-modified biochar with peroxymonosulfate (Fe-BC/PMS) under sunlight and solar photo-Fenton (SPF) with iron-EDDS at circumneutral pH. Aqueous matrix effect was also investigated comparing the effect in tap water with SUWW. The presence of high concentration of MPs (1.0 g/L) in tap water sped up micropollutants degradation (80 % removal in 20 min) for Fe-BC/PMS/sunlight treatment in comparison to MP absence condition (80 % removal only after 60 min). On the contrary, micropollutants degradation efficiency by SPF treatment in tap water decreased by 27 % in presence of MPs (1.0 g/L). MPs did not significantly affect micropollutants removal in SUWW. Moreover, MPs presence reduced E. coli inactivation (both total and AR E. coli) efficiency (2.2 log units) by Fe-BC/PMS/sunlight treatment, which was attributed to the UV light scattering/blocking effect. Pilot scale results in a raceway pond photoreactor for simultaneous micropollutants removal and bacteria inactivation in SUWW showed 60 % higher micropollutants degradation for SPF with EDDS (103 kJ/m2). Whereas Fe-BC/PMS/sunlight treatment achieved complete inactivation of E. coli (<2 CFU/100 mL) in comparison to SPF with Fe:EDDS (0.5 log unit reduction) after 45 min treatment (103 kJ/m2).

One material, two functions: A dual-mechanistic approach for the removal of persistent and mobile organic micropollutants from drinking water

Organic micropollutants (OMP), especially those that are more persistent and mobile due to their physico-chemical properties, are resistant to common water treatment techniques and might reach drinking water. Considering the wide range and different physico-chemical properties of persistent and mobile (PM) substances, the strategic integration of synergistic processes appears as a promising solution for the removal of persistent and mobile substances. In this study, the development of a dual-functional material is explored for synergistic adsorption and catalysis, presenting a dual-mechanistic approach for removing potentially persistent and mobile substances from drinking water. The material was fabricated using waste materials (coffee and aluminum wastes) and tested for removing 23 selected OMP. The results demonstrate that the dual-functional material can both adsorb some target OMP and activate persulfate to oxidize OMP by generating reactive oxygen species (ROS). Recycling of the material in repeated cycles revealed removal of several OMP even in 5th cycle, using 0.5 g/L of the synthesized material, 0.5 mM persulfate and 1 h contact time. Quenching experiments indicated that singlet oxygen (1O2) is the dominant ROS in the proposed system, implying that it is a non-radical advanced oxidation process.

Carbon-based metal oxide nanocomposites for water treatment by photocatalytic processes

The increasing contamination of water by emerging contaminants and the need for more efficient and sustainable treatment methods have prompted the exploration of advanced materials and technologies, with a particular focus on photocatalysis. Carbon-based metal oxide nanocomposites are a promising solution for the treatment of polluted water. This paper aims to review the current state of research on the application of these nanocomposites as photocatalysts for complete water treatment, describing breakthroughs in contaminant removal from 2019 through 2024 and milestones in water disinfection from 2016 through 2024. It includes discussion on the utilization of nanocomposites of Metal Oxides (MOs) with carbon materials to improve photocatalytic efficiency and addresses the advantages and drawbacks of these materials, including electron-hole recombination and agglomeration. The review focuses on the photocatalytic mechanisms of these nanocomposites and highlights the importance of heterostructures formed between metal oxides and carbon materials (e.g., graphene, carbon nanotubes, and carbon quantum dots), which enhance light absorption and hydroxyl radical generation, thereby increasing the efficiency of pollutant degradation and water disinfection. The review describes the properties of different MOs (n-type and p-type), exploring synergies between MOs and carbon materials and discussing the benefits and challenges of their application in wastewater treatment and pathogen inactivation. The review ends with a scientometric analysis of research trends in this field.

Systematic study of the synergistic and kinetics effects on the removal of contaminants of emerging concern from water by ultrasound in the presence of diverse oxidants

The enhancement of the ultrasound system by adding diverse oxidants to remove a model contaminant (acetaminophen, ACE) in water was investigated. Different parameters were evaluated to study their effect on both the degradation kinetics and the synergy of the combination. The variables studied were the ultrasonic frequency (575, 858, and 1135 kHz), type of oxidant (hydrogen peroxide, sodium peroxydisulfate (or persulfate, PDS), and potassium peroxymonosulfate (PMS)), ACE concentration (4, 8, and 40 µM), and oxidant concentration (0.01, 0.1, 1, and 5 mM). Particular interest was placed on synergistic effects, implying that one process (or both) is activated by the other to lead to greater efficiency. Interestingly, the parameters that led to the higher synergistic effects did not always lead to the most favorable degradation kinetics. An increase in ACE removal of 20% was obtained using the highest frequency studied (1135 kHz), PMS 0.1 mM, and the highest concentration of ACE (40 µM). The intensification of degradation was mainly due to the ability of ultrasound to activate oxidants and produce extra hydroxyl radicals (HO•) or sulfate radicals (SO4•-). Under these conditions, treatment of ACE spiked into seawater, hospital wastewater, and urine was performed. The hospital wastewater matrix inhibited ACE degradation slightly, while the urine components inhibited the pollutant degradation completely. The inhibition was mainly attributed to the competing organic matter in the effluents for the sono-generated radical species. On the contrary, the removal of ACE in seawater was significantly intensified due to "salting out" effects and the production of the strong oxidant HOCl from the reaction of chloride ions with PMS.

Lignocellulose biosorbents: Unlocking the potential for sustainable environmental cleanup

Climate change, the overconsumption of fossil fuels, and rapid population and economic growth have collectively driven a growing emphasis on environmental sustainability and the need for effective resource management. Chemicals or materials not currently regulated are known as contaminants of emergent concern (CECs). Nevertheless, wastewater is thought to be its main source, and worries about its probable presence in the environment are growing due to its potential damage to human and environmental health. To counteract hazardous chemicals in wastewater and promote ecological sustainability, there has been a significant deal of interest in finding environmentally benign and renewable materials. Because of its constituents' distinct physical and chemical qualities, lignocellulose stands out among the many possibilities as the most appealing possibility for water cleanup. It is an abundant, biocompatible, and renewable substance. Sustainable social development requires wastewater cleanup using renewable lignocellulosic resources. However, the generation of lignocellulose-based materials is restricted by the byproducts that are produced and the complicated, expensive, and environmentally harmful synthetic process. It has been determined that biosorption on lignocellulosic wastes and by-products is a suitable substitute for the current technologies used to remove hazardous metal ions and dye from wastewater streams. Lignocellulose is highly effective at adsorbing heavy metals like arsenic (As), cadmium (Cd), copper (Cu), chromium (Cr), and lead (Pb). Beyond heavy metals, it can also capture various organic pollutants, that includes dyes (like methylene blue, methyl orange and malachite green), and pharmaceutical residues, and pesticides. Additionally, lignocellulosic materials are valuable for adsorbing oil and hydrocarbons from water, playing a crucial role in addressing environmental concerns related to oil spills. The pollutant removal efficiency of lignocellulose can be greatly improved through a range of physical, chemical, and biological modification methods, including thermal and ultrasound treatments, acid and alkali processing, ammoniation, amination, grafting, crosslinking, enzymatic modifications, and microbial colonization. In this article, we examine the most recent developments in lignocellulose-based adsorbent research, with an emphasis on lignocellulosic composition, adsorbent application, and material modification. A methodical and thorough presentation of the preparation and modification techniques for lignin, cellulose, and hemicellulose, as well as their utilization for treating various types of contaminated water, is provided. Additionally, a great resource for comprehending the specified adsorption mechanism and recycling of adsorbents is the thorough explanation of the mechanism of adsorption, the adsorbent renewal process, and the adsorption model.

An S-Scheme MOF-on-MXene Heterostructure for Enhanced Photocatalytic Periodate Activation

Fully understanding the periodate (PI) activation system is still a great challenge, which calls for efficient heterogeneous catalysts with a sophisticated structure. Herein, we developed "MOF-on-MXene" heterostructures. By constructing S-scheme heterostructures MXene/Z67450, the internal electric field is generated via the Ti-O-Co bonds at the interface, favoring the excitation of the photogenerated electrons, providing a driving force for accelerating the charge transfer, and enhancing redox performances. Further contributed by the synergy of Ti-O-Co and Co-N4 bonds, the MXene/Z67450 composites exhibit enhanced ability for activating the periodate system to degrade organic pollutants via building a donor-catalyst-acceptor system. In the presence of periodate and light, MXene/Z67450 degraded ∼100% of tetracycline hydrochloride (TCH) in only 10 min. The active sites of the heterostructures can react with the periodate and give the intermediate MXene/Z67450-PI (*PI). As a result, it efficiently reduced the PI adsorption energy and promoted the decomposition of PI and the formation of holes/electrons, singlet oxygen (1O2) as well as hydroxyl radical (•OH). In addition, the MXene/Z67450 composites exhibit high stability, reusability, selectivity, and environmental robustness. Our study provides a research direction for rationally designing MXene-based heterojunctions and applying them in the periodate activation system.

Selected emerging contaminants in water: Global occurrence, existing treatment technologies, regulations and associated risk

Emerging contaminants (ECs) in aquatic environments have recently attracted the attention of researchers due to their ubiquitous occurrence and the potential risk they may pose to life. While advance analytical methods have improved global reporting in water matrices, additional information is needed to compile data on their occurrence, existing legislation, treatment technologies and associated human health risks. Therefore, the present study provides an overview of the occurrence of selected ECs, including personal care product, antibiotics, NSAIDs, EDCs and psychiatric drugs, the existing regulatory framework and their toxicological effects on human health. The water matrices under review are the treated wastewater, surface water, groundwater and, in a few cases, drinking water. The study also highlights different treatment technologies available, and evaluates their performance based on the removal efficiency for different classes of ECs. For removal of almost all ECs considered, ozonation integrated with gamma radiation was reported highly efficient. Risk analysis was also performed for selected ECs including diclofenac, ibuprofen, naproxen, carbamazepine, estrone, 17 β-estradiol, bisphenol A, sulfamethoxazole, erythromycin and triclosan. The human health risk analysis indicated the highest number of locations with potential risk due to the EDCs, with South America, Europe and Asia having multiple risks due to estrone and Bisphenol A. The results of this study will give a better insight into the current situation of ECs in the global water matrices, the performance assessment of treatment technologies and the risk analysis will describe the need for more robust regulatory structures around the world to prevent the occurrence of such contaminants in the aquatic environment.

Investigating the application of novel filling materials in Vertical Subsurface Flow Constructed Wetlands for the treatment of anaerobic effluents originating from domestic wastewater

Vertical subsurface flow constructed wetlands (VSSF CWs) were employed to investigate the use of biochar that could be produced with local agricultural biomass through pyrolysis, recycled glass from local recycling companies and gel beads with decreased packing volume and shipping cost as substrate alternatives to sand. The materials were assessed in terms of granulometry, porosity, adsorption capacity and hydraulic conductivity and were used for the treatment of an upflow anaerobic sludge blanket (UASB) reactor, treating domestic wastewater, effluent. Granulometry was a major factor impacting TSS removal that ranged from 81% ± 10% to 97% ± 2%. The COD removal was affected by granulometry, porosity and the active biofilm formation, since biochar removal was slightly higher (up to 93% ± 3%) than that of sand and recycled glass (up to 86% ± 4% and 85% ± 5%, respectively) and significantly higher than that of gel beads (up to 68% ± 8%). The higher porosity of biochar affected NH4-N removal in which adsorption had a greater and longer effect. The overall NH4-N removal ranged between 84% ± 11% and 99% ± 1% for all materials. Sand, biochar and glass achieved an 80% average removal of selected contaminants of emerging concern (CECs), including ibuprofen (IBU), naproxen (NPX), triclosan (TCS), bisphenol A (BPA), diclofenac (DCF) and ketoprofen (KFN). The biochar and recycled glass are effective in treating UASB effluent and enable the treated wastewater reuse, since, high compliance rates with the EU Regulation 2020/741 - Class A were achieved (>98% for TSS, >88% for BOD5 and 100% for turbidity).

Development of a new method using dispersive liquid-liquid microextraction with hydrophobic natural deep eutectic solvent for the analysis of multiclass emerging contaminants in surface water by liquid chromatography-mass spectrometry

A new analytical method was developed for the determination of 14 multiclass emerging organic contaminants in surface waters using LC-MS, and Dispersive Liquid-Liquid Microextraction (DLLME) for extraction. Different Natural Deep Eutectic Solvents (NADESs) composed of terpenes and organic acids were tested as extraction solvents and characterized by Fourier Transform Infrared Spectroscopy (FTIR), Hydrogen Nuclear Magnetic Resonance Spectroscopy (1H-NMR), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), density, and viscosity, eliminating the need to use traditional chlorinated solvents. NADES produced with butyric acid and thymol showed the best results and was selected for application for the first time in the extraction of emerging organic contaminants of different classes in water samples. Vortex was used as the dispersion mode, eliminating the use of the dispersion solvent. Chromatographic conditions and sample preparation were optimized using multivariate experimental designs. The optimized chromatographic conditions included the column oven temperature, mobile phase modifiers, and stationary phase type. The optimized conditions for sample preparation included the extraction temperature and pH, salting out effect, and extraction solvent volume. The analytical performance was evaluated through repeatability and intermediate precision tests, with RSD values below 20%, and recoveries between 70 and 120%. The coefficient of determination was greater than 0.98 for all analytes. LOQs varied between 1.5 and 35 μg L-1. DLLME is a simple technique, it does not require expensive and specific equipment. Furthermore, replacing traditional chlorinated solvents with NADES makes the procedure more environmentally friendly. The method presented here can be applied to a wide range of analytes for the analysis of fresh, brackish, and salt waters. Up to the present moment, this is the first study using NADES based thymol and butyric acid for the determination of multiclass emerging contaminants in surface waters samples.

Evidence for high-risk pollutants and emerging microbial contaminants at two major bathing ghats of the river Ganga using high-resolution mass spectrometry and metagenomics

An efficient wastewater treatment plant is imperative to limit the entry of emerging pollutants (EPs) and emerging microbial contaminants (EMCs) in the river ecosystem. The detection of emerging EPs in aquatic environments is challenging due to complex sample preparation methods, and the need for sophisticated accurate analytical tools. In Varanasi (India), the river Ganga holds immense significance as a holy river but is consistently polluted with municipal (MWW) and hospital wastewater (HWW). We developed an efficient method for untargeted detection of EPs in the water samples using High-resolution mass spectrometry (HRMS), and identified 577 and 670 chemicals (or chemical components) in the water samples from two major bathing ghats, Assi Ghat (AG) and Dashashwamedh Ghat (DG), respectively. The presence of EPs of different categories viz chemicals from research labs, diagnostic labs, lifestyle and industrial chemicals, toxins, flavor and food additives indicated the unsafe disposal of MWW and HWW or inefficient wastewater treatment plants (WWTPs). Besides, shotgun metagenomic analysis depicted the presence of bacteria associated with MWW viz Cloacibacterium normanse, Sphaerotilus natans (sewage fungi), E. coli, and Prevotella. Also, the presence of human pathogens Arcobacter, Polynucleobacter, Pseudomonas, Klebsiella, Aeromonas, Acinetobacter, Vibrio, and Campylobacter suggests the discharge of HWW. EPs are linked to the development, and transmission of antimicrobial resistance (AMR). Occurrence of antibiotic resistance genes (ARGs), plasmid-borne β-lactamases, aminoglycoside transferases, and ARGs associated with integrons, transposons and plasmids viz mcr-3 gene that confer resistance to colistin, the last resort of antibiotics confirmed the presence of emerging microbial contaminants. Subsequent genome reconstruction studies showed the presence of uncultivable ARB and transmission of ARGs through horizontal gene transfer. This study can be used to monitor the health of aquatic bodies as well as the efficiency of WWTPs and raise an urgent need for efficient WWTPs to safeguard the river, Ganga.

The fate of atenolol in wastewater treatment plants of representative densely urban agglomerations in China

Atenolol (ATL) that can decrease heart rate and reduce renin release is extensively used in the treatment of hypertension, angina, and other diseases. ATL's popularity has therefore drawn attention to its environmental behavior and potential impacts. Wastewater treatment plants (WWTPs) are the main collection point for ATL entering the water environment, highlighting the necessity of studying its fate in the environment. In this study, five WWTPs with different processes in China's representative densely urban agglomerations (Pearl River Delta [PRD] region) were selected as certain representative sampling sites to investigate the fate of ATL in the WWTPs over four seasons. Results showed that ATL concentration in the influent of these WWTPs was 146.5-918.6 ng/L and the corresponding concentration in the effluent was 43.0-534.1 ng/L, achieving a certain degree of removal. The seasonal ATL removal performance varied greatly among these WWTPs, Liede, Tai Po, and Sha Tin WWTPs showed better removal stability. Meanwhile, the average ATL removal rates in Tai Po (83.36%) and Sha Tin (81.67%) were higher than those in the Futian (71.24%), Liede (55.44%), and Stonecutters Island WWTPs (44.96%). The primary treatment capacity of Futian WWTP was better than that of Tai Po and Sha Tin WWTPs in removing ATL, while the performance of secondary treatment was opposite. Moreover, Zahn-Wellens test demonstrated that ATL could be almost completely degraded after 30 days and some protonated molecules (e.g., m/z 145 and m/z 190) metabolites were formed, indicating that degradation may play a role in ATL removal in WWTPs.

Environmental fate of organic UV filters: Global occurrence, transformation, and mitigation via advanced oxidation processes

Organic UV filters are used in personal care products, plastics, paints, and textiles to protect against UV radiation. Despite regulatory limits, these compounds still enter the environment through direct wash-off during swimming, evaporation, leaching from products, and incomplete removal in wastewater treatment plants. They have been detected in various environmental matrices worldwide. Once in the environment, organic UV filters can undergo phototransformation and biotransformation, forming transformation products that, together with parent substances, pose health risks to humans and wildlife and harm marine ecosystems, especially coral reefs. The increasing concern over water scarcity and the environmental impact of pollutants underscores the importance of eliminating these contaminants from aquatic environments. This review primarily focuses on organic UV filters approved for use in sunscreens, many of which are also utilized in other materials, with a few exceptions including UV stabilizer UV-328. It includes an in-depth analysis of 155 peer-reviewed articles published from 2015 to 2024, assessing the concentrations of these filters in various environmental matrices, including water and solid matrices, air and biota. Moreover, this review explores the environmental transformation of these chemicals and assesses the effectiveness of advanced oxidation processes (AOPs) in removing these pollutants. The findings highlight the pervasive presence of organic UV filters in the environment and the promising potential of AOPs to mitigate the associated environmental challenges.

Online control of UV and UV/H2O2 processes targeted for the removal of contaminants of emerging concern (CEC) by a fluorescence sensor

This study assessed the online and real-time monitoring of contaminants of emerging concern (CEC) using a microbial/tryptophan-like fluorescence sensor in a quaternary AOP (advanced oxidation process) pilot plant installed downstream of a tertiary municipal wastewater treatment plant (WWTP). Real-time fluorescence measurements were validated with lab-scale tryptophan-like fluorescence. Changes in water quality induced by different UV or UV/H2O2 doses were detected by the fluorescence sensor allowing real-time control of processes. The removal of CEC was discussed considering their photo-susceptibility and reactivity with •OH and then classified into three groups based on their reactivity and removal efficiency (RE). Linear models of CEC removal developed using real-time fluorescence removal as a surrogate parameter resulted very accurate (overall R2≥0.90) for most of CEC. Furthermore, real-time fluorescence data were successfully used to predict i) pseudo-observed first-order degradation rate constants of CEC (R2=0.99), and ii) UV doses during both UV and UV/H2O2 processes (R2>0.90). The findings of this study demonstrated that fluorescence sensors can be employed in operational relevant environment to monitor a broad range of CEC and control UV doses during UV-AOPs. Therefore, the implementation of fluorescence sensors is expected for optimizing costs, energy consumption and efficiency of quaternary wastewater treatments.

Applying a novel mechanistic framework for drinking water management to mitigate emerging contaminants

A novel framework has been developed which summarizes the efficacy of treatment technologies for emerging contaminants (ECs) based on the general mitigation mechanisms of Removal, Inactivation/Degradation, and Destruction (i.e., RIDD). The RIDD framework allows for a concise critical evaluation of the efficacy of treatment processes for their mitigation potential, and provides an efficient methodology for drinking water system managers to identify knowledge gaps related to the management of ECs in water treatment with respect to current technologies available in practice. Additionally, the RIDD framework provides an understanding of the treatment processes which provide: (1) broad spectrum treatment, (2) effective mitigation for certain categories of contaminants or under certain circumstances, or (3) little or no mitigation of ECs. In the proposed format, this information is intended to assist water managers to make more informed treatment decisions. Four categories of ECs noted in recent literature as presently concerning to drinking water utilities, including both anthropogenic and microbial contaminants, were used in this study to provide examples of RIDD framework application. In many cases, broad-spectrum treatment barriers (e.g., high-pressure membranes) are expected to provide cost-effective management of a suite of ECs, which then can be compared to the costs and practicality of additional treatment barriers for individual ECs (e.g., selective ion exchange resins or tailored biological processes). Additionally, understanding the typical performance of existing treatment processes can help assist with capital planning for alternative treatment processes or upgrades, or for developing novel treatment approaches at the watershed scale such as integrated urban water management and One Water frameworks.

Virus Removal from Real Wastewater as an Environmental Management Approach

The increased presence of resistant microorganisms in water promotes the need for supplementary measures to mitigate the water source's contamination. Traditional treatments are inefficient in wastewater management at removing some emerging contaminants. Corbicula fluminea, an invasive species, can be used in the treatment due to their resistance and biofiltration capacity, working as a pest management strategy. In this study, this bivalve was used to promote the virus disinfection from the municipal wastewater treatment plant (MWTP) that enters (influent) and after the secondary treatment (effluent leaving the plant). JC virus, norovirus (GI, GII), and hepatitis A (HAV) were identified. C. fluminea promoted norovirus GI and GII removal after 72 h and a slight decrease in the JC virus concentration. These results prove the potential of this pest management approach to be used in virus removal. Furthermore, infectivity assays using mengovirus confirmed the correlation between the presence of the genome detected by PCR and the infectious virus particles. This highlights the potential of PCR as a reliable indicator of the infectious virus's presence. However, such an infectivity assay proved that even when PCR results are undetectable, a reduced number of viruses may remain viable and able to infect susceptible cells in culture.

Charge as a key physicochemical factor in adsorption of organic micropollutants from wastewater effluent by rice husk bio-silica

Wastewater treatment plants (WWTPs) often fail to fully remove organic micro-pollutants (OMPs), necessitating advanced treatment methods. This study examines the potential of an agricultural waste-derived adsorbent, rice husk (RH) - silica, for removing a complex mixture of 20 OMPs in MilliQ water and wastewater effluent. While RH-silica shows potential for OMP removal, its performance with multicomponent mixtures in real wastewater has yet to be investigated. Batch experiments demonstrated the efficacy of RH-silica in removing cationic, neutral, polar, and non-polar OMPs across various pH levels, with no adsorption of anionic OMPs. Column elution studies revealed that only positively charged compounds did not reach a breakthrough after 300 specific bed volumes (BVs), even when the filtration velocity was increased fivefold (3.8 m/h) and lower adsorbent-to-volume ratios (0.5 g/L) were employed. This indicates that electrostatic interactions via deprotonated silanol groups are the primary adsorption mechanism. RH-silica's ability to retain cationic pollutants regardless of their hydrophilicity degree highlights its potential as a novel adsorbent targeting positively charged persistent and mobile organic compounds (PMOCs). Moreover, the adsorption efficiency remained high in experiments with real wastewater effluent. Considering practical applications, a RH-silica column could be used to enhance removal of cationic polar compounds. This approach not only improves pollutant removal efficiency but also contributes to sustainability in WWTPs by using agricultural waste resources. Despite significant operational and end-of-life challenges for large-scale implementation, this study represents a crucial advancement in the investigation of RH-silica as an adsorbent.

The variation of resistome, mobilome and pathogen in domestic and industrial wastewater treatment systems

Wastewater treatment plants (WWTPs), including both domestic and industrial facilities, are key contributors to antibiotic resistance genes (ARGs) and human pathogens in the environment. However, the characteristics and dissemination mechanisms of ARGs in domestic (SD) and industrial (SI) wastewater treatment systems remain unclear, leading to uncertainties in risk assessment. Based on metagenomic analysis, we observed significant differences in the compositions of resistome (ARGs and metal resistance genes, MRGs), mobilome (mobile genetic elements, MGEs), and bacterial community between SD and SI. SI exhibited lower diversity of ARGs but higher abundance of MRGs compared to SD. The removal efficiency of resistome was lower in the SI than that in the SD. MGEs emerged as the primary driver of ARG dissemination in the WWTPs, followed by the bacterial community. Environmental conditions (physicochemical parameters, heavy metals, and antibiotics) indirectly influenced the variation of resistome. Significantly, environmental conditions and MGEs highly influenced the composition of resistome in the SI, while bacterial community more associated with resistome in the SD. Additionally, we identified 36 human bacterial pathogens as potential hosts of ARGs, MRGs, and MGEs in wastewater samples. This study provides new insights on the dissemination mechanisms and risk assessment of antimicrobial resistance in the different types of WWTPs.

Photoelectrocatalytic degradation of organophosphate esters using tio2 electrodes produced from 3d-printed ti substrates

3D printed electrode substrates with novel geometries may significantly improve the efficacy of photoelectrocatalysis for degradation of recalcitrant pollutants such as organophosphate flame retardants (OPFRs). However, the 3D printed substrates often have an irregular topology that can lead to a less uniform arrangement of nanotubes following anodisation. This study investigated the effect of polishing 3D-printed Ti substrates prior to anodisation to form TiO2 nanotube array electrodes, and their subsequent applicability for photoelectrocatalytic treatment of OPFRs in water matrices. Polished and non-polished electrodes exhibited differences in morphology in terms of average roughness, (0.38 and 3.10 µm, respectively), leading to more uniform TiO2 nanotubes of the former. Water contact angle measurements revealed the non-polished electrode was super-hydrophilic and the polished electrode hydrophilic (water contact angles of 6.4˚ and 16.1˚, respectively). Despite these differences, the polished and non-polished electrodes exhibited very similar electrochemical responses. In fact, the purity and electrical conductivity of water matrices affected the photoelectrocatalytic performance more than the electrode morphology. The purified water (PW) matrix facilitated the highest degradation/removal of OPFRs, compared to tap water matrices. In particular, individual OPFR degradation levels in PW were 74% ± 9, 37% ± 10, 33% ± 9, 31% ± 11 and 3% ± 5 for triphenyl phosphate, tris(butyl) phosphate, tris(isobutyl) phosphate, tris(2-butoxyethyl) phosphate and tris(2-chloroisopropyl) phosphate, respectively. The removal of OPFRs was relative to their reactivity to hydroxyl radicals, which was higher for the aryl then alkyl straight-chain and then chlorinated compounds. This study reveals that polishing of electrode substrates is not required for the preparation of effective photoelectrocatalytic reactors to treat recalcitrant pollutants (e.g. OPFRs), Importantly, future development of novel high-profile 3D printed electrode will not be hindered by the requirement to polish the substrates prior to anodisation.

Comparative life cycle assessment of non-thermal plasma for the removal of pharmaceuticals from wastewater

Wastewater effluents are a continuous source of pharmaceuticals in water bodies, which pose a serious environmental threat to aquatic ecosystems. This work provides a comprehensive technical, environmental and cost assessments of different advanced quaternary treatments for wastewater effluents, with special focus on novel Non-Thermal Plasma technology. For this porpouse Non-Thermal Plasma, Sand Filtration + Ozonation, Ultrafiltration, Ultrafiltration + Nanofiltration and Ultrafiltration + Reverse Osmosis technologies were compared with UV disinfection-based technology. This work applies the Life Cycle Analysis tool for the impact environmental assessment using both ReciPE 2016(H) method and, for a more detailed analysis of the contribution of pharmaceuticals to freshwater ecotoxicity category of impact, the USETOX method, which was integrated with 7 new characterisation factors. The results obtained showed overall removal efficiency of pharmaceuticals always higher than 80%, with performances in descending order of Ultrafiltration + Reverse Osmosis > Sand Filtration + Ozonation > Ultrafiltration + Nanofiltration > Non-Thermal Plasma, being Sand Filtration + Ultraviolet disinfection and standalone Ultrafiltration comparatively not suitable for pharmaceuticals removal. Regarding the target pharmaceuticals proposed on the EU Directive 271/91 revision, the Non-Thermal Plasma perform better towards venlafaxine than Sand Filtration + Ozonation, and towards diclofenac and carbamazepine than Ultrafiltration + Nanofiltration. Ultrafiltration + Nanofiltration and Non-Thermal Plasma showed better environmental performance than Sand Filtration + Ozonation and Ultrafiltration + Reverse Osmosis in 7 out of 18 categories of impact (ReciPe method), with Ultrafiltration + Nanofiltration being more advantageous than Non-Thermal Plasma in human and ecotoxicity-related categories of impact, and Non-Thermal Plasma more advantageous in Global Warming, Fossil Resource Scarcity, and Fine Particulate Matter Formation. Regrading Freshwater Ecotoxicity (USEtox method), the quaternary treatment configuration and its energy demand affect the Freshwater final value of impact more than the presence of pharmaceuticals. Under the conditions tested, the Non-Thermal Plasma provided the lower OPEX (0.24 € m-3) than other tested technologies, showing an interesting compromise between pharmaceuticals removal efficiency, environmental impacts, and economic operational cost.

Nature-based bioreactors: Tackling antibiotic resistance in urban wastewater treatment

The overuse and misuse of antibiotics have accelerated the selection of antibiotic-resistant bacteria, significantly impacting human, animal, and environmental health. As aquatic environments are vulnerable to antibiotic resistance, suitable management practices should be adopted to tackle this phenomenon. Here we show an effective, nature-based solution for reducing antibiotic resistance from actual wastewater. We utilize a bioreactor that relies on benthic (biofilms) and planktonic microbial communities to treat secondary effluent from a small urban wastewater treatment plant (<10,000 population equivalent). This treated effluent is eventually released into the local aquatic ecosystem. We observe high removal efficiency for genes that provide resistance to commonly used antibiotic families, as well as for mobile genetic elements that could potentially aid in their spread. Importantly, we notice a buildup of sulfonamide (sul1 and sul2) and tetracycline (tet(C), tet(G), and tetR) resistance genes specifically in biofilms. This advancement marks the initial step in considering this bioreactor as a nature-based, cost-effective tertiary treatment option for small UWWTPs facing antibiotic resistance challenges.

Heterogeneous Catalytic Ozonation of Pharmaceuticals: Optimization of the Process by Response Surface Methodology

Batch heterogeneous catalytic ozonation experiments were performed using commercial and synthesized nanoparticles as catalysts in aqueous ozone. The transferred ozone dose (TOD) ranged from 0 to 150 μM, and nanoparticles were added in concentrations between 0 and 1.5 g L-1, with all experiments conducted at 20 °C and a total volume of 240 mL. A Ce-doped TiO2 catalyst (1% molar ratio of Ce/Ti) was synthesized via the sol-gel method. Response surface methodology (RSM) was applied to identify the most significant factors affecting the removal of selected pharmaceuticals, with TOD emerging as the most critical variable. Higher TOD resulted in greater removal efficiencies. Furthermore, it was found that the commercially available metal oxides α-Al2O3, Mn2O3, TiO2, and CeO2, as well as the synthesized CeTiOx, did not increase the catalytic activity of ozone during the degradation of ibuprofen (IBF) and para-chlorobenzoic acid (pCBA). Carbamazepine (CBZ) and diclofenac (DCF) are compounds susceptible to ozone oxidation, thus their complete degradation at 150 μM transferred ozone dose was attained. The limited catalytic effect was attributed to the rapid consumption of ozone within the first minute of reaction, as well as the saturation of catalyst active sites by water molecules, which inhibited effective ozone adsorption and subsequent hydroxyl radical generation (●OH).

The impact of plasma-activated water on the process of nickel bioremediation by Neowestiellopsis persica A1387

Cyanobacteria provide an economical, feasible, and environmentally friendly solution for heavy metal removal. In addition, plasma can facilitate the removal of heavy metals across various time frames. In this study, we applied plasma-activated water (PAW) to prepare Neowestiellopsis persica A1387 strain medium culture for 0, 10, 15, and 20 min via an Atmospheric Cold Plasma Jet device (ACPJ-17A). Nickel removal efficiency was evaluated after 48 hours of cultivation under controlled conditions at 0, 10, 30, 60, and 90 min. Further investigation was performed through FTIR, GC-MS, and XRD techniques. Statistical analysis of ANOVA and Tukey's test indicated that the samples treated for 15 min had the highest biomass dry weight, polysaccharide content, and nickel removal rate (p ≤ 0.05). The GC-MS analysis presented elevated concentrations of ethanol, 1,3-dimethylbenzene, acetic acid, 3-methylbutyl ester, aromatic chemicals, 2-methyl-1-propanol, and 3-octen-2-ol in all samples treated with plasma. The functional group analysis using the FT-IR approach showed increased peak intensities with more extended treatment periods, indicating the addition of methyl, methylene, and hydroxyl groups to the cyanobacterium cell wall. Furthermore, a peak at 468 cm⁻¹ wavelength was observed, correlating to the Ni-O stretching mode after absorption of Ni on the cyanobacterium surface. The XRD data exhibited prominent peaks in all diffraction patterns angles below 20 degrees, suggesting the presence of amorphous and non-crystalline chemical structures within the cyanobacterial structures. The peak intensity increased with longer treatment durations. The 15-min plasma treatment optimized Ni removal, but the efficiency decreased with prolonged exposure due to adverse effects such as increased reactive oxygen species (ROS) production.

Removal of persistent and mobile organic micropollutants from drinking water utilizing a synthesized waste-derived adsorbent

Persistent and mobile (PM) substances refer to a wide range of organic micropollutants (OMPs) with high persistence and mobility in water. So far, only a few methods have been explored for the removal of PM substances from drinking water. In this work, a new adsorbent based on spent coffee grounds and aluminum waste was synthesized and utilized to remove 25 OMPs, including 22 PM substances, from drinking water. Different characterization methods, including powder X-ray diffraction (XRD), analyses according to Brunauer-Emmett-Teller (BET), field-emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDS), were applied to describe the adsorbent's textural and structural characteristics. The results revealed that the adsorbent is highly effective in removing OMPs. Common OMPs (i.e. carbamazepine, sulfamethoxazole and diclofenac) were completely removed from drinking water. Also, many of the PM substances were removed by more than 80% using an adsorbent dosage of 0.1 g/L. A strong relation between abatement of ultraviolet light absorbance at 254 nm (UV254) and OMP removal was observed. Therefore, UV254 abatement is a useful surrogate for a quick estimation of OMP removals.

What is the Difference between Conventional Drinking Water, Potable Reuse Water, and Nonpotable Reuse Water? A Microbiome Perspective

As water reuse applications expand, there is a need for more comprehensive means to assess water quality. Microbiome analysis could provide the ability to supplement fecal indicators and pathogen profiling toward defining a "healthy" drinking water microbiota while also providing insight into the impact of treatment and distribution. Here, we utilized 16S rRNA gene amplicon sequencing to identify signature features in the composition of microbiota across a wide spectrum of water types (potable conventional, potable reuse, and nonpotable reuse). A clear distinction was found in the composition of microbiota as a function of intended water use (e.g., potable vs nonpotable) across a very broad range of U.S. water systems at both the point of compliance (Betadisper p > 0.01; ANOSIM p < 0.01, r-stat = 0.71) and point of use (Betadisper p > 0.01; ANOSIM p < 0.01, r-stat = 0.41). Core and discriminatory analysis further served in identifying distinct differences between potable and nonpotable water microbiomes. Taxa were identified at both the phylum (Desulfobacterota, Patescibacteria, and Myxococcota) and genus (Aeromonas and NS11.12_marine_group) levels that effectively discriminated between potable and nonpotable waters, with the most discriminatory taxa being core/abundant in nonpotable waters (with few exceptions, such as Ralstonia being abundant in potable conventional waters). The approach and findings open the door to the possibility of microbial community signature profiling as a water quality monitoring approach for assessing efficacy of treatments and suitability of water for intended use/reuse application.

Factors in the decline of the African penguin: Are contaminants of emerging concern (CECs) a potential new age stressor?

The African penguin is currently experiencing a significant decline, with just over 10,000 breeding pairs left. A substantial body of research reflects the impacts of contaminants of emerging concern (CECs) on the marine environment, with wastewater treatment plants reported as one of the main sources of CEC release. In South Africa, CECs were identified contaminating the marine environment and bioaccumulating in several marine species. Approximately 70 % of all African penguin colonies breed in close proximity to cities and/or harbors in South Africa. Currently, the impact of CECs as a stressor upon the viability of African penguin populations is unknown. Based on the search results there was a clear lack of information on CECs' bioaccumulation and impact on the African penguin. This narrative review will thus focus on the prevalent sources and types of CECs and examine the reported consequences of constant exposure in seabirds, particularly African penguins.

Optimization of the Photo-Fenton process for the effective removal of chemical oxygen demand and phenols in portable toilet wastewater: A treatment study under real world conditions

Wastewater from portable toilets (WWPT) is characterized by a high content of organic matter and a variety of chemical compounds that retain bad odors, especially phenols, a type of pollutant that is difficult to degrade by conventional treatments; in addition, it is persistent, toxic, and accumulates in the aquatic environment. Although different successful experiences with the use of Photo-Fenton are reported in the scientific domain, its application in WWPT is scarce and warrants study due to the wide use of portable toilets. The objective of this study was to evaluate the Photo-Fenton oxidation process in the removal of organic matter expressed as COD in a WWPT, as well as the reduction of phenols and BOD5. The experimental runs were carried out in a 0.50 L batch reactor to evaluate the effect of the factors (H2O2: 0.019, 25.56, 40.67, 87.24, 148.91, 174.45 g L-1 and pH: 2.80, 3.00, 3.27, 4.40, 5.53, 6.00 UNT) on COD removal and sludge production. It was found that the optimum operating conditions of pH 4.72 and H2O2 dosage of 174.45 g L-1 reduced the concentration of phenols by 97.83 % and 95.49 % of COD. In addition, 98.01 % of BOD5 was reduced, resulting in a biodegradability ratio (BOD5/COD) of 0.23 compared to the untreated wastewater of 0.53. From a cost perspective, the use of Photo-Fenton to treat wastewater under these conditions would be US$ 1.15 per liter.

The Role of Wastewater Treatment Plants in Dissemination of Antibiotic Resistance: Source, Measurement, Removal and Risk Assessment

Antibiotic Resistance Genes (ARGs) are contaminants of emerging concern with marked potential to impact public and environmental health. This review focusses on factors that influence the presence, abundance, and dissemination of ARGs within Wastewater Treatment Plants (WWTPs) and associated effluents. Antibiotic-Resistant Bacteria (ARB) and ARGs have been detected in the influent and the effluent of WWTPs worldwide. Different levels of wastewater treatment (primary, secondary, and tertiary) show different degrees of removal efficiency of ARGs, with further differences being observed when ARGs are captured as intracellular or extracellular forms. Furthermore, routinely used molecular methodologies such as quantitative polymerase chain reaction or whole genome sequencing may also vary in resistome identification and in quantifying ARG removal efficiencies from WWTP effluents. Additionally, we provide an overview of the One Health risk assessment framework, as well as future strategies on how WWTPs can be assessed for environmental and public health impact.

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

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

Water self-purification via electron donation effect of emerging contaminants arousing oxygen activation over ordered carbon-enhanced CoFe quantum dots

The release of emerging contaminants (ECs) into aquatic environments poses a significant risk to global water security. Advanced oxidation processes (AOPs), while effective in removing ECs, are often resource and energy-intensive. Here, we introduce a novel catalyst, CoFe quantum dots embedded in graphene nanowires (CoFeQds@GN-Nws), synthesized through anaerobic polymerization. It uniquely features electron-rich and electron-poor micro-regions on its surface, enabling a self-purification mechanism in wastewater. This is achieved by harnessing the internal energy of wastewater, particularly the bonding energy of pollutants and dissolved oxygen (DO). It demonstrates exceptional efficiency in removing ECs at ambient temperature and pressure without the need for external oxidants, achieving a removal rate of nearly 100.0%. The catalyst's structure-activity relationship reveals that CoFe quantum dots facilitate an unbalanced electron distribution, forming these micro-regions. This leads to a continuous electron-donation effect, where pollutants are effectively cleaved or oxidized. Concurrently, DO is activated into superoxide anions (O2•-), synergistically aiding in pollutant removal. This approach reduces resource and energy demands typically associated with AOPs, marking a sustainable advancement in wastewater treatment technologies.

Nitrofurantoin removal by the photo-Fenton process: degradation, mineralization, and biological inactivation

Antibiotics may induce super-resistant bacteria if they are available in the environment. Therefore, the removal of aqueous nitrofurantoin (NFT), and more importantly, the removal of the remaining antimicrobial activity after treatment, by the photo-Fenton process, was herein studied. Degradation experiments were performed according to an experimental design (0.5% error; factors: concentrations of NFT, Fe3+, and H2O2). Degradation conditions were: 20 mg NFT L-1, 10 mg Fe3+ L-1, and 170 mg H2O2 L-1. Fixed parameters were: 100 mL of the NFT solution, pH 2.5, 15-min stirring, and 25.0 ± 0.5°C. The initial rate constant (k0) and the maximum oxidation capacity (MOC) of the system were 0.61 min-1 and 100%, respectively (R2 = 0.986). 97% of the NFT and 93% of the organic carbon initially present were removed. Five degradation products (DPs) were detected by HPLC-MS and their endpoints estimated by the ECOSAR (ECOlogical Structure-Activity Relationships) 2.0 software. NFT and its DPs presented no toxicity towards Lactuca sativa. The antimicrobial activity (Escherichia coli) of NFT and/or DPs was completely removed in 15 min. Structures were proposed for the detected DPs. In short, the tested advanced oxidation technology (AOP), besides being capable of removing and mineralizing aqueous NFT in a short time, 15 min, also rendered the treated water biologically inactive (no ecotoxicity, no antimicrobial activity).

Identifying PFAS hotspots in surface waters of South Carolina using a new optimized total organic fluorine method and target LC-MS/MS

Per- and polyfluoroalkyl substances (PFAS) are environmental contaminants of concern due to their long persistence in the environment, toxicity, and widespread presence in humans and wildlife. Knowledge regarding the extent of PFAS contamination in the environment is limited due to the need for analytical methods that can reliably quantify all PFAS, since traditional target methods using liquid chromatography (LC)-mass spectrometry (MS) fail to capture many. For a more comprehensive analysis, a total organic fluorine (TOF) method can be used as a screening tool. We combined TOF analysis with target LC-MS/MS analysis to create a statewide PFAS hotspot map for surface waters throughout South Carolina. Thirty-eight of 40 locations sampled contained detectable concentrations of organic fluorine (above 100 ng/L). Of the 33 target PFAS analyzed using LC-MS/MS, the most prevalent were perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluoroheptanoic acid (PFHpA), and perfluorohexanesulfonate (PFHxS). On average, LC-MS/MS only accounted for 2 % of the TOF measured. Locations with high TOF did not necessarily correlate to high total quantified PFAS concentrations and vice-versa, demonstrating the limitations of target PFAS analysis and indicating that LC-MS may miss highly contaminated sites. Results suggest that future surveys should utilize TOF to more comprehensively capture PFAS in water bodies.

Synergistic adsorption and photocatalytic degradation of tetracycline using a Z-scheme kaolin/g-C3N4/MoO3 nanocomposite: A sustainable approach for water treatment

This research focuses on the synthesis and application of a novel kaolin-supported g-C3N4/MoO3 nanocomposite for the degradation of tetracycline, an important antibiotic contaminant in water systems. The nanocomposite was prepared through a facile and environmentally friendly approach, leveraging the adsorption and photocatalytic properties of kaolin, g-C3N4 and MoO3 nanoparticles, respectively. Comprehensive characterization of the nanocomposite was conducted using techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and optical spectra. The surface parameters were studied using N2 adsorption-desorption isotherm. The elemental composition was studied using X-ray photoelectron spectroscopy. The efficiency of the developed nanocomposite in tetracycline degradation was evaluated and the results revealed an efficient tetracycline degradation exhibiting the synergistic effects of adsorption and photocatalytic degradation in the removal process. The tetracycline degradation was achieved in 60 min. Kinetic studies and thermodynamic analyses provided insights into the degradation mechanism, suggesting potential applications for the nanocomposite in wastewater treatment. Additionally, the recyclability and stability of the nanocomposite were investigated, demonstrating its potential for sustainable and long-term application in water treatment.

Iron Nanoparticle-Incorporated Laser-Induced Graphene Filters for Environmental Remediation via an In Situ Electro-Fenton Process

Laser-induced graphene (LIG) has garnered much attention due to its facile and chemically free fabrication technique. Metal nanoparticle incorporation into the LIG matrix can improve its electrical and catalytical properties for environmental application. Here, we demonstrate the fabrication of nanoscale zerovalent iron (nZVI) nanoparticle-incorporated LIG (Fe-LIG) and sulfidized-nanoscale zerovalent iron (S-nZVI) nanoparticle-incorporated LIG (SFe-LIG) surfaces. The sheets were first fabricated to investigate nanoparticle loading, successful incorporation in the LIG matrix, and electrochemical performance as electrodes. Fe-LIG and SFe-LIG sheets showed ∼3-3.5 times more charge density as compared with the control LIG sheet. The XPS and its deconvolution confirmed the presence of nZVI and S-nZVI in the Fe-LIG and SFe-LIG surfaces, which can generate in situ hydroxyl radical (•OH) via iron activation of electrogenerated hydrogen peroxide (H2O2) in short in situ electro-Fenton process. After confirmation of the successful incorporation of iron-based nanoparticles in the LIG matrix, filters were fabricated to demonstrate the application in the flow-through filtration. The Fe-LIG and SFe-LIG filters showed ∼10-30% enhanced methylene blue removal under the application of 2.5 V at ∼1000 LMH flux. The Fe-LIG and SFe-LIG filters also showed complete 6-log bacteria and virus removal at 2.5 and 5 V, respectively, while the LIG filters showed only ∼4-log removal. Such enhanced removal by the Fe-LIG and SFe-LIG filters as compared to LIG filters is attributed to the improved charge density, electrochemical activity, and in situ electro-Fenton process. The study shows the potential to develop catalytic LIG-based surfaces for various applications, including contaminant removal and microbial inactivation.

Modelling and optimization of membrane process for removal of biologics (pathogens) from water and wastewater: Current perspectives and challenges

As one of the 17 sustainable development goals, the United Nations (UN) has prioritized "clean water and sanitation" (Goal 6) to reduce the discharge of emerging pollutants and disease-causing agents into the environment. Contamination of water by pathogenic microorganisms and their existence in treated water is a global public health concern. Under natural conditions, water is frequently prone to contamination by invasive microorganisms, such as bacteria, viruses, and protozoa. This circumstance has therefore highlighted the critical need for research techniques to prevent, treat, and get rid of pathogens in wastewater. Membrane systems have emerged as one of the effective ways of removing contaminants from water and wastewater However, few research studies have examined the synergistic or conflicting effects of operating conditions on newly developing contaminants found in wastewater. Therefore, the efficient, dependable, and expeditious examination of the pathogens in the intricate wastewater matrix remains a significant obstacle. As far as it can be ascertained, much attention has not recently been given to optimizing membrane processes to develop optimal operation design as related to pathogen removal from water and wastewater. Therefore, this state-of-the-art review aims to discuss the current trends in removing pathogens from wastewater by membrane techniques. In addition, conventional techniques of treating pathogenic-containing water and wastewater and their shortcomings were briefly discussed. Furthermore, derived mathematical models suitable for modelling, simulation, and control of membrane technologies for pathogens removal are highlighted. In conclusion, the challenges facing membrane technologies for removing pathogens were extensively discussed, and future outlooks/perspectives on optimizing and modelling membrane processes are recommended.

Application of catalytic ozonation using Y zeolite in the elimination of pharmaceuticals in effluents from municipal wastewater treatment plants

Catalytic ozonation using faujasite-type Y zeolite with two different SiO2/Al2O3 molar ratios (60 and 12) was evaluated for the first time in the removal of 25 pharmaceutical compounds (PhCs) present in real effluents from two municipal wastewater treatment plants both located in the Mediterranean coast of Spain. Additionally, control experiments including adsorption and direct ozonation, were conducted to better understand the fundamental aspects of the different individual systems in wastewater samples. Commercial zeolites were used in sodium form (NaY). The results showed that the simultaneous use of ozone and NaY zeolites significantly improved the micropollutants degradation rate, able to degrade 95 % of the total mixture of PhCs within the early 9 min using the zeolite NaY-12 (24.4 mg O3 L-1 consumed), while 12 min of reaction with the zeolite NaY-60 (31 mg O3 L-1 consumed). In the case of individual experiments, ozonation removed 95 % of the total mixture of PhCs after 25 min (46.2 mg O3 L-1 consumed), while the direct adsorption, after 60 min of contact time, eliminated 30 % and 44 % using the NaY-12 and NaY-60 zeolites, respectively. Results showed that the Brønsted acid sites seemed to play an important role in the effectiveness of the treatment with ozone. Finally, the environmental assessment showed that the total risk quotients of pharmaceuticals were reduced between 87 %-99 % after ozonation in the presence of NaY-60 and NaY-12 zeolites. The results of this study demonstrate that catalytic ozonation using NaY zeolites as catalysts is a promising alternative for micropollutant elimination in real-world wastewater matrices.

Geopolymer-Based Materials for the Removal of Ibuprofen: A Preliminary Study

Every year, new compounds contained in consumer products, such as detergents, paints, products for personal hygiene, and drugs for human and veterinary use, are identified in wastewater and are added to the list of molecules that need monitoring. These compounds are indicated with the term emerging contaminants (or Contaminants of Emerging Concern, CECs) since they are potentially dangerous for the environment and human health. To date, among the most widely used methodologies for the removal of CECs from the aquatic environment, adsorption processes play a role of primary importance, as they have proven to be characterized by high removal efficiency, low operating and management costs, and an absence of undesirable by-products. In this paper, the adsorption of ibuprofen (IBU), a nonsteroidal anti-inflammatory drug widely used for treating inflammation or pain, was performed for the first time using two different types of geopolymer-based materials, i.e., a metakaolin-based (GMK) and an organic-inorganic hybrid (GMK-S) geopolymer. The proposed adsorbing matrices are characterized by a low environmental footprint and have been easily obtained as powders or as highly porous filters by direct foaming operated directly into the adsorption column. Preliminary results demonstrated that these materials can be effectively used for the removal of ibuprofen from contaminated water (showing a concentration decrease of IBU up to about 29% in batch, while an IBU removal percentage of about 90% has been reached in continuous), thus suggesting their potential practical application.

Insight into the key factors and mechanism of excellent tetracycline adsorption on amorphous cobalt carbonate nanosheets

The extensive use of tetracyclines (TCs) has led to their widespread distribution in the environment, causing serious harm to ecosystems because of their toxicity and resistance to decomposition. Adsorption is presently the principal approach to dispose of TCs, and the development of excellent adsorbents is crucial to TC removal. Herein, a novel amorphous cobalt carbonate hydroxide (ACCH) was successfully prepared by a one-step solvothermal method, which was identified as Co(CO3)0·63(OH)0.74·0.07H2O. The ultimate adsorption capacity of ACCH for TC reaches 2746 mg g-1, and the excellent adsorption performance can be maintained over a wide pH (3.0-11.0) and temperature (10-70 °C) range. Moreover, ACCH also exhibits a wonderful adsorption performance for other organic contaminants, such as ciprofloxacin and Rhodamine B. The TC adsorption process can be reasonably described by the pseudo-second-order kinetic model, intraparticle model and Langmuir isothermal model. The experimental results in this work suggest that the excellent adsorption performance of ACCH is ascribed to the large specific surface area, alkaline characteristics and numerous functional groups of ACCH. Accordingly, this work provides a promising strategy for the development of highly-efficient adsorbents and demonstrates their application prospects in environmental remediation.

Emerging contaminants in water environments: progress, evolution, and prospects

This article employs bibliometric tools like VOSviewer, Bibliometrix, and CiteSpace for a comprehensive visual analysis of 1,612 documents on Emerging Contaminants in Waters from the Web of Science database. The objective is to elucidate the historical development, research hotspots, and trends in international studies of this field, offering valuable insights and guidance for future research directions. The analysis reveals a consistent increase in publications from 2003 to 2023, with the United States, China, and Spain being the most prolific contributors. A detailed examination of keyword co-occurrence and cluster analysis shows a predominant focus on themes such as pollutant detection, risk assessment, and biogeochemical cycling. Furthermore, the study underscores the significance of forming interdisciplinary networks among authors and institutions, highlighting its critical role in enhancing the quality and innovation of scientific research. The findings of this study not only chart the progression and focal points of research in this domain but also underscore the pivotal role of international collaboration, serving as an indispensable reference for shaping future research trajectories and fostering global cooperation.

Wastewater treatment in lagoons: A systematic review and a meta-analysis

This study has carried out a systematic review of 36 scientific papers (reporting 63 case studies) published in the last 15 years about the treatment of industrial, agri-food and municipal wastewater in lagoons. A concentration of studies from a few countries (Italy, Algeria and Iran) and about municipal wastewater (70% of papers) was revealed by the bibliographic analysis. Aeration was supplied in more than 50% of case studies; the storage capacity of lagoons (adopted as a measure of size) was extremely variable (over seven orders of magnitude), while their depth was generally lower than a few metres. The efficiency of lagoon treatments at removing COD was in a wide range (25-98%). Very few studies analysed the energy intensity of treatments in lagoons. The meta-analysis applied to a further selection of 10 papers with 29 case studies revealed significant differences in pH and dissolved oxygen concentration, due to aeration or type of treated wastewater. Treatment efficiency was higher in aerated lagoons compared to non-aerated systems, and did not depend on the type of treated wastewater. Based on the analysis of the reviewed papers, an urgent research need on this topic arises, mainly due to the oldness of most analysed studies. Practical suggestions are given to optimise the depuration performances of lagoons: (i) application of intermittent and night aeration; (ii) reduced air flow rates; (iii) adaptation of microbial biomass to high contents of inhibiting compounds in wastewater; (iv) construction of baffles to keep the planned hydraulic retention time avoiding short-circuit; (v) integration of lagoons with other treatments (e.g., constructed wetlands); (vi) ferti-irrigation of crops with lagoon effluents rather than disposal into water bodies.

Assessment of new hydrogen peroxide activators in water and comparison of their active species toward contaminants of emerging concern

Advanced oxidation processes are the most efficient tool to thwart the overaccumulation of harmful organic compounds in the environment. In this direction bioinspired metal complexes may be a viable solution for oxidative degradations in water. However, their synthesis is often elaborated and their scalability consequently low. This study presents alternative easy-to-synthesize bioinspired metal complexes to promote degradations in water. The metals employed were iron and manganese ions, hence cheap and highly accessible ions. The complexes were tested toward Phenol, Estrone, Triclosan, Oxybenzone, Diclofenac, Carbamazepine, Erythromycin, Aspartame, Acesulfame K, Anisole and 2,4-Dinitrotoluene. The reaction favoured electron-rich compounds reaching a removal efficiency of over 90%. The central ion plays a crucial role. Specifically, Mn(II) induces a non-radical pathway while iron ions a predominant radical one (⋅OH is predominant). The iron systems resulted more versatile toward contaminants, while the manganese ones showed a higher turn-over number, hence higher catalytic behaviour.

High resolution mass spectrometry-based screening for the comprehensive investigation of organic micropollutants in surface water and wastewater from Pasto city, Colombian Andean highlands

The complexity of the aquatic environment scenario, including the impact of urban wastewater, together with the huge number of potential hazardous compounds that may be present in waters, makes the comprehensive characterization of the samples an analytical challenge, particularly in relation to the presence of organic micropollutants (OMPs). Nowadays, the potential of high-resolution mass spectrometry (HRMS) for wide-scope screening in environmental samples is out of question. Considering the physicochemical characteristics of OMPs, the coupling of liquid (LC) and gas chromatography (GC) to HRMS is mandatory. In this work, we have explored the combined use of LC and GC coupled to Quadrupole-Time-of-Flight Mass Spectrometry (QTOF MS) for screening of surface water and wastewater samples from Pasto (Nariño), a town of the Colombian Andean highlands (average altitude 2527 m), located in an important agricultural area. The upper basin of the Pasto River is impacted by phytosanitary products used in different crops, whereas the domestic wastewater is directly discharged into the river without any treatment, enhancing the anthropogenic impact on the water quality. The OMP searching was made by target (standards available) and suspect (without standards) approaches, using home-made databases containing >2000 compounds. Up to 15 pesticides (7 insecticides, 6 fungicides and 2 herbicides) were identified in the sampling point of the Pasto River up to the town, while no pharmaceuticals were found at this site, illustrating the impact of agriculture practices. On the contrary, 14 pharmaceuticals (7 antibiotics and 3 analgesics, among others) were found in river samples collected in the middle and down to the town sites, revealing the impact of the urban population. Interestingly, some transformation products, including metabolites, such as carbofuran-3-hydroxy and 4-acetylamino antipyrine were identified in the screening. Based on these data, future monitoring will apply target quantitative LC-MS/MS methods for the most relevant compounds identified.

Single-crystal vs polycrystalline boron-doped diamond anodes: Comparing degradation efficiencies of carbamazepine in electrochemical water treatment

The ongoing challenge of water pollution by contaminants of emerging concern calls for more effective wastewater treatment to prevent harmful side effects to the environment and human health. To this end, this study explored for the first time the implementation of single-crystal boron-doped diamond (BDD) anodes in electrochemical wastewater treatment, which stand out from the conventional polycrystalline BDD morphologies widely reported in the literature. The single-crystal BDD presented a pure diamond (sp3) content, whereas the three other investigated polycrystalline BDD electrodes displayed various properties in terms of boron doping, sp3/sp2 content, microstructure, and roughness. The effects of other process conditions, such as applied current density and anolyte concentration, were simultaneously investigated using carbamazepine (CBZ) as a representative target pollutant. The Taguchi method was applied to elucidate the optimal operating conditions that maximised either (i) the CBZ degradation rate constant (enhanced through hydroxyl radicals (•OH)) or (ii) the proportion of sulfate radicals (SO4•-) with respect to •OH. The results showed that the single-crystal BDD significantly promoted •OH formation but also that the interactions between boron doping, current density and anolyte concentration determined the underlying degradation mechanisms. Therefore, this study demonstrated that characterising the BDD material and understanding its interactions with other process operating conditions prior to degradation experiments is a crucial step to attain the optimisation of any wastewater treatment application.

A multi-scenario risk assessment strategy applied to mixtures of chemicals of emerging concern in the River Aconcagua basin in Central Chile

Environmental risk assessments strategies that account for the complexity of exposures are needed in order to evaluate the toxic pressure of emerging chemicals, which also provide suggestions for risk mitigation and management, if necessary. Currently, most studies on the co-occurrence and environmental impacts of chemicals of emerging concern (CECs) are conducted in countries of the Global North, leaving massive knowledge gaps in countries of the Global South. In this study, we implement a multi-scenario risk assessment strategy to improve the assessment of both the exposure and hazard components in the chemical risk assessment process. Our strategy incorporates a systematic consideration and weighting of CECs that were not detected, as well as an evaluation of the uncertainties associated with Quantitative Structure-Activity Relationships (QSARs) predictions for chronic ecotoxicity. Furthermore, we present a novel approach to identifying mixture risk drivers. To expand our knowledge beyond well-studied aquatic ecosystems, we applied this multi-scenario strategy to the River Aconcagua basin of Central Chile. The analysis revealed that the concentrations of CECs exceeded acceptable risk thresholds for selected organism groups and the most vulnerable taxonomic groups. Streams flowing through agricultural areas and sites near the river mouth exhibited the highest risks. Notably, the eight risk drivers among the 153 co-occurring chemicals accounted for 66-92 % of the observed risks in the river basin. Six of them are pesticides and pharmaceuticals, chemical classes known for their high biological activity in specific target organisms.

Environmentally safe biopolymer-clay composite for efficient adsorption of ciprofloxacin in fresh and saline solutions

In alignment with the sustainable development goals (SDGs), recent trends in water management have been directed toward using environmentally friendly bio-based materials for removing contaminants. In this work, we prepared a biocomposite of chitosan (CS) intercalated into acid activated calcium bentonite (Bent). A thermally stable mesoporous CS-Bent composite was prepared with a zeta potential of 15.5 to -34.4 mV in the pH range of 2.22-10. The biocomposite successfully removed up to 99.2% and 50 mg/g of the antibiotic ciprofloxacin HCl (CPX) at pH 5.5 via electrostatic and hydrogen bonding forces. In a multi-component aqueous system of heavy metal and CPX, the composite was more selective to CPX than to the heavy metals and removal of CPX in this system was comparable to that in a single-component system. The composite also maintained its high adsorption efficiency in NaCl solutions which makes it suitable for treating fresh and saline solutions. The combination of CS and bent produced a biodegradable eco-friendly composite characterized with good thermal and surface properties along with efficient and selective adsorption performance.

A critical and comprehensive review of the current status of 17β-estradiol hormone remediation through adsorption technology

Even at low concentrations, steroid hormones pose a significant threat to ecosystem health and are classified as micropollutants. Among these, 17β-estradiol (molecular formula: C18H24O2; pKa = 10.46; Log Kow = 4.01; solubility in water = 3.90 mg L-1 at 27 °C; molecular weight: 272.4 g mol-1) is extensively studied as an endocrine disruptor due to its release through natural pathways and widespread use in conventional medicine. 17β-estradiol (E2) is emitted by various sources, such as animal and human excretions, hospital and veterinary clinic effluents, and treatment plants. In aquatic biota, it can cause issues ranging from the feminization of males to inhibiting plant growth. This review aims to identify technologies for remediating E2 in water, revealing that materials like graphene oxides, nanocomposites, and carbonaceous materials are commonly used for adsorption. The pH of the medium, especially in acidic to neutral conditions, affects efficiency, and ambient temperature (298 K) supports the process. The Langmuir and Freundlich models aptly describe isothermal studies, with interactions being of a low-energy, physical nature. Adsorption faces limitations when other ions coexist in the solution. Hybrid treatments exhibit high removal efficiency. To mitigate global E2 pollution, establishing national and international standards with detailed guidelines for advanced treatment systems is crucial. Despite significant advancements in optimizing technologies by the scientific community, there remains a considerable gap in their societal application, primarily due to economic and sustainable factors. Therefore, further studies are necessary, including conducting batch experiments with these adsorbents for large-scale treatment along with economic analyses of the production process.

Bioinspired Stevia rebaudiana Green Zinc Oxide Nanoparticles for the Adsorptive Removal of Antibiotics from Water

Green zinc oxide nanoparticles (ZnO NPs) synthesized using Stevia rebaudiana as a reducing agent were investigated as ecofriendly adsorbents for the removal of the antibiotics ciprofloxacin (CIP) and tetracycline (TET) from water. Green ZnO NPs were synthesized using a rapid novel approach that did not require annealing or calcination at high temperatures to produce mesoporous NPs with a size range of 37.36-71.33 nm, a specific surface area of 15.28 m2/g, and a negative surface charge of -15 mV at pH 5. The green ZnO NPs exhibited an antioxidant activity of 85.57% at 250 μg/mL and an antibacterial activity with MIC and MBC of 50 and 100 mg/mL, respectively, against both Escherichia coli and Staphylococcus aureus. The best adsorption performance was achieved using a 4 g/L dose and pH 5, yielding, respectively, 86.77 ± 0.82% removal and 27.07 ± 0.26 mg/g adsorption capacity for CIP at 10 mg/L and 67.86 ± 3.41% and 15.88 ± 0.37 mg/g for TET at 25 mg/L. The green ZnO NPs achieved 79.71% ± 0.28 and 61.55% ± 0.53 removal of 10 mg/L CIP and 25 mg/L TET, respectively, in a spiked tap water binary system of the two contaminants. Adsorption of CIP and TET occurred mainly via electrostatic interactions, whereby CIP was bound more strongly than TET by virtue of its charge and size. The synthesis and adsorption processes were evaluated by a stepwise regression statistical model to optimize their parameters. Lastly, the green ZnO NPs were regenerated and reused for 5 cycles, indicating their functionality as simple, reusable, and low-cost adsorbents for the removal of CIP and TET from wastewater, in accordance with SDGs #6 and 12 for the sustainable management of water.