Chitosan supported hetero-metallic bio-nanocomposites for paracetamol removal from homogeneous solutions and heterogeneous mixtures with focused antibacterial studies.

Biopolymers infused with bimetallic nanoparticles exhibit a wide range of functionalities necessary for efficiently eliminating diverse water contaminants. However, the protracted production process requires further exploration. As such, present study seeks to optimize microwave-assisted technique for the facile synthesis of cross-linked chitosan (CTS) supported bimetallic-oxide nanoparticles, specifically zinc oxide (ZnO) and iron-oxide (Fe3O4), denoted as CTS-TTP/Zn-Fe. The primary objective is to investigate the efficacy of these beads in the removal of Paracetamol (PCM) from single and complex water matrices while also assessing their antibacterial properties. Characterization includes chemical composition, surface structures, thermal stability, and magnetic properties. The experimental results demonstrated that CTS-TPP/Zn-Fe beads achieved a remarkable PCM removal efficiency of ~99 % (qm = 4.98 mg g-1), with a Zn:Fe mole ratio of 1:1. The experimental data showed good applicability with Freundlich isotherm and chemisorption-supported rate models (R2 > 0.9). To evaluate the long-term viability and practicality of these beads, three crucial field applicability tests were conducted. These encompassed competition studies with other pharmaceuticals, desorption investigations for repeated use, and efficiency evaluations in an ionic solution. Collectively, this research provides a comprehensive understanding, spanning from material design to practical applications, with potential relevance for large-scale wastewater treatment when coupled with appropriate flux control measures.

Fate of emerging contaminants in an advanced SBR wastewater treatment and reuse facility incorporating UF, RO, and UV processes.

A critical factor for widescale water reuse adoption is the capability of advanced wastewater treatment facilities to consistently produce high-quality water by efficiently removing various pollutants, including emerging contaminants (ECs). This study monitored the fate of seventeen ECs (which included pesticides, antibiotics and other pharmaceutically active compounds) over six months in an advanced wastewater reuse facility situated in the United Arab Emirates. The facility integrates a sequencing batch reactor (SBR) based sewage treatment plant (STP) with a water recycling facility featuring ultrafiltration (UF), reverse osmosis (RO), and ultraviolet (UV) disinfection. ECs were detected and quantified at the influent and effluents of the various treatment stages, using an ultra-high-performance liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QTOF-MS). The STP exhibited variable removal efficiencies, achieving >90 % removal for compounds like caffeine and acetaminophen, while others, such as carbamazepine and thiabendazole, displayed poor removal (<10 %). UF treatment broadly resulted in limited removal, with ECs in permeate typically persisting in the 1-10 ng/L range. Subsequently, after undergoing RO treatment, eight ECs were still detected in the RO permeate, albeit at <1 ng/L, except for imidacloprid (2.5 ng/L). Conversely, the final UV disinfection step led to concentration increases of certain ECs, namely imidacloprid, thiabendazole, sulfamethoxazole, sulfamethazine and caffeine. Overall, the total EC concentration levels decreased considerably from 2300 ng/L in the STP influent to 5.2 ng/L in the RO permeate. However, a subsequent increase to 27.5 ng/L was observed after UV disinfection. While the study underscores the effectiveness of advanced treatment processes, notably RO, in reducing EC concentrations, it also demonstrates the importance of continuous EC monitoring in such facilities as many compounds persist post treatment. Additionally, the potential for processes like UV disinfection to increase certain EC concentrations highlights the need to optimize treatment trains to minimize EC concentration rebound.

Sustainable control of microplastics in wastewater using the electrochemically enhanced living membrane bioreactor.

Wastewater treatment plant (WWTP) discharges are major contributors to the release of microplastics (MPs) into the environment. This research work aimed to assess the performance of the novel living membrane bioreactor (LMBR), which utilizes a biological layer as a membrane filter for the removal of polyethylene (PE) MPs from wastewater. The impact of an intermittently applied low current density (0.5 mA/cm2) on the reduction of MPs in the electrochemically enhanced LMBR (e-LMBR) has also been examined. The reactors were also compared to a conventional membrane bioreactor (MBR) and an electro-MBR (e-MBR). 1H nuclear magnetic resonance spectroscopy (1H NMR) was implemented for the MPs detection and quantification in terms of mass per volume of sample. The LMBR and MBR achieved comparable mean PE MPs reduction at 95% and 96%, respectively. The MPs mass reduction in the e-LMBR slightly decreased by 2% compared to that achieved in the LMBR. This potentially indicated the partial breakdown of the MPs due to electrochemical processes. Decreasing and inconsistent NH4-N and PO4-P removal efficiencies were observed over time due to the addition of PE MPs in the MBR and LMBR. In contrast, the integration of electric field in the e-MBR and e-LMBR resulted in consistently high values of conventional contaminant removals of COD (99.72-99.77 %), NH4-N (97.96-98.67%), and PO4-P (98.44-100.00%), despite the MPs accumulation. Integrating electrochemical processes in the e-LMBR led to the development of a stable living membrane (LM) layer, as manifested in the consistently low effluent turbidity 0.49 ± 0.33 NTU. Despite the increasing MPs concentration in the mixed liquor, applying electrochemical processes reduced the fouling rates in the e-LMBR. The e-LMBR achieved comparable efficiencies in contaminant reductions as those observed in the e-MBR, while using a low-cost membrane material.

Identification of organic contaminants in water and related matrices using untargeted liquid chromatography high-resolution mass spectrometry screening with MS/MS libraries.

Nontargeted and suspect screening with liquid chromatography-high resolution mass spectrometry (LC-HRMS) has become an indispensable tool for quality assessment in the aquatic environment - complementary to targeted analysis of organic (micro)contaminants. An LC-HRMS method is presented, suitable for the analysis of a wide variety of water related matrices: surface water, groundwater, wastewater, sediment and sludge, including extracts from passive samplers and on-site solid phase enrichment, while focusing on the data processing aspect of the method. A field study is included to demonstrate the practical application and versatility of the whole process. HRMS/MS data were recorded following LC separation in both (ESI) positive and negative ionization modes using data dependent as well as data independent acquisition. Two vendor (Agilent's Personal Compound Database and Library and from National Institute of Standards and Technology) and one open (MassBank/EU) tandem mass spectral libraries were utilized for the identification of compounds via mass spectral match. The development of a novel software tool for parsing, grouping and reduction of MS/MS features in data files converted to mascot generic format (MGF) helped to substantially decrease the amount of time and effort needed for MS library search. While applying the method, in the course of the entire field study, 18771 detections (from 870 individual compounds) in total were recorded in 275 samples, resulting in 68.3 identified compounds per sample, on average. Among the top ten most frequently detected contaminants across all samples and sample types were pharmaceutical compounds carbamazepine, 4-acetamidoantipyrine, 4-formylaminoantipyrine, tramadol, lamotrigine and phenazone and industrial contaminants toluene-2-sulfonamide, tolytriazole, tris(2-butoxyethyl) phosphate and benzotriazole. Exploratory data analysis methods and tools enabled us to discover organic pollutant occurrence patterns within the comprehensive sets of qualitative data collected from various projects between the years 2018-2023. The results may be used as valuable inputs for future water quality monitoring programs.

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.

Multifaceted effects of microplastics on soil-plant systems: Exploring the role of particle type and plant species.

Microplastics have emerged as a global environmental concern, yet their impact on terrestrial environments, particularly agricultural soils, remains underexplored. Agricultural soils, due to intensive farming, may serve as significant sinks for microplastics. This study investigated the effects of different types of microplastics-polyester microfibers, polyethylene terephthalate microfragments, and polystyrene microspheres-on soil properties and radish growth, while a complementary experiment examined the impact of polyester microfibers on the growth of lettuce and Chinese cabbage. Through both horizontal and vertical comparisons, this research comprehensively evaluated the interactions between microplastic particles and plant species in soil-plant systems. The results showed that polyester microfibers significantly affected soil bulk density, with effects varying based on planting conditions (p < 0.01). Polyethylene terephthalate microfragments and polystyrene microspheres reduced the proportion of small soil macroaggregates under radish cultivation (p < 0.01). Additionally, polystyrene microspheres significantly altered the total organic carbon stock in radish-growing soil, potentially affecting the microclimate (p < 0.01). Interestingly, polyester microfibers promoted lettuce seed germination and significantly enhanced the root biomass of Chinese cabbage (p < 0.05). Overall, the environmental effects of microplastic exposure varied depending on the type of particle and plant species, suggesting that microplastics are not always harmful to soil-plant systems and may even offer benefits in certain scenarios. Given the crucial role of soil-plant systems in terrestrial ecosystems, and their direct connection to food safety, human health, and global change, further research should explore both the positive and negative impacts of microplastics on agricultural practices.

Effect of physicochemical parameters on the occurrence of per- and polyfluoroalkyl substances (PFAS) in aquatic environment.

Perfluoroalkyl substances (PFAS) and their distribution in aquatic environments have been studied extensively, but more information is needed to link these occurrences to their physicochemical characteristics. Understanding how these parameters influence PFAS can help predict their fate, mobility, and occurrences in water. This study reviewed the influence of physicochemical parameters on the occurrences of PFAS in aquatic environment using the relevant keywords to retrieve articles from databases spanning mostly between 2017 and 2024. The result suggests that high pH, turbidity, and dissolved oxygen, give high concentration of PFAS, while high electrical conductivity, temperature and salinity give low PFAS concentration in the water. Therefore, monitoring and safeguarding the aquatic bodies for human and environmental safety is imperative. Future studies should include the effects of the physicochemical properties on PFAS occurrences in the natural environment and focus on an organism's distinctive characteristics to comprehend the bioaccumulation and biomagnification of PFAS in them and environmental matrices.

Distribution characteristics and sources of ultraviolet absorbents in facility agricultural soils in China.

The environmental contamination of ultraviolet absorbents (UVAs) has attracted global attention for the persistence, bioaccumulation and ecotoxicity. However, little is known about the content and distribution characteristics of UVAs in agricultural soils, especially in facility agricultural soils. In this study, the contents and distribution characteristics of 16 UVAs were surveyed in agricultural facility soils (N = 61) and field soil samples (N = 61) from 27 provinces in China. The total content of 16 UVAs (Σ16UVAs) in facility soils (mean 64.2 ± 55.4 ng/g) was higher than that in field soils (mean 9.66 ± 7.66 ng/g), suggesting that UVAs in facility soils are associated with mulch film. The Σ16UVAs content in the soil mulched with biodegradable (PBAT) film was higher than that in the soil mulched with polyethylene (PE) film, which indicated that the UVA pollution in the soil mulched with biodegradable film was more serious. With the continuous promotion of the use of biodegradable films may pose a threat to soil and ecological health. Therefore, studies on the content and distribution characteristics of UVAs in facility soils are needed to provide scientific basis for the controlling and monitoring of novel pollutants.

Di(2-ethylhexyl) phthalate disrupts circadian rhythm associated with changes in metabolites and cytochrome P450 gene expression in Caenorhabditis elegans.

The plasticizer di(2-ethylhexyl) phthalate (DEHP) is a widespread environmental pollutant due to its extensive use. While circadian rhythms are inherent in most living organisms, the detrimental effects of DEHP on circadian rhythm and the underlying mechanisms remain largely unknown. This study investigated the influence of early developmental exposure to DEHP on circadian rhythm and explored the possible relationship between circadian disruption and DEHP metabolism in the model organism Caenorhabditis elegans. We observed that DEHP disrupted circadian rhythm in a dose-dependent fashion. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis revealed that DEHP-induced circadian disruption accompanies with altered proportions of DEHP metabolites in C. elegans. RNA sequencing data demonstrated that DEHP-induced circadian rhythm disruption caused differential gene expression. Moreover, DEHP-induced circadian disruption coincided with attenuated inductions of DEHP-induced cytochrome P450 genes, cyp-35A2, cyp-35A3, and cyp-35A4. Notably, cyp-35A2 mRNA exhibited circadian rhythm with entrainment, but DEHP exposure disrupted this rhythm. Our findings suggest that DEHP exposure disrupts circadian rhythm, which is associated with changes in DEHP metabolites and cytochrome P450 gene expression in C. elegans. Given the ubiquitous nature of DEHP pollution and the prevalence of circadian rhythms in living organisms, this study implies a potential negative impact of DEHP on circadian rhythm and DEHP metabolism in organisms.

Deep learning models for predicting plant uptake of emerging contaminants by including the role of plant macromolecular compositions.

Deep learning models can predict uptake of emerging contaminants in plants with improved accuracy because they leverage advanced data-driven approaches to capture non-linear relationships that traditional models struggle to address. Traditional models suffer from low accuracy in predicting transpiration stream concentration factor (TSCF) and root concentration factor (RCF). This study applied deep neural networks (DNN), recurrent neural networks (RNN), and long short-term memory (LSTM) to enhance the accuracy of predictive models for TSCF and RCF. The three models used nine chemical properties and two plant root macromolecular compositions for predicting TSCF and RCF. The results indicated that deep learning models predict TSCF and RCF with improved accuracy compared to mechanistic models. The coefficient of determination (R2) for the DNN, RNN, and LSTM models in predicting TSCF was 0.62, 0.67, and 0.56, respectively. The corresponding mean squared error (MSE) on the test set for the models was 0.055, 0.035, and 0.060, respectively. The R2 for the DNN, RNN, and LSTM models in predicting RCF was 0.90, 0.91, and 0.84, respectively. The corresponding MSE for the models was 0.124, 0.071, and 0.126, respectively. The results of feature extraction using extreme gradient boosting underlined the importance of lipophilicity and root lipid fraction.

Pesticides under the category of persistent organic pollutants and emerging contaminants in surface sediments of an Arctic Fjord and nearby lakes.

This study focuses on the distribution of some selected organochlorine pesticides and emerging contaminants within the surface sediments of an Arctic fjord, Kongsfjorden and nearby lakes. Organochlorine pesticides (OCPs) such as dicloran, p,p'-DDT, p,p'-DDE, p,p'-DDD were studied along with five emerging contaminants namely diuron, chlorpyrifos, dicofol, pendimethalin and bifenthrin. The highest values of OCPs recorded among the fjord and lake environments during the time of study was 0.3355 ng/g (dicloran), 0.0152 ng/g (p,p'-DDT), 0.0117 ng/g (p,p'-DDE), and 0.0137 ng/g (p,p'-DDD). Except dicofol, all other pesticides were found in both the years (2018 & 2019) with an elevated concentration during 2019. The presence of fresh as well as past input of contaminants was obtained from the values of DDTs ratio. The sediment quality guidelines of DDTs confirm that the fjord and lakes are clean to marginally polluted in which the adverse effects can rarely occur at this present juncture.

The abundance and analytical characterization of microplastics in the surface water of Haryana, India.

Microplastic (MP) contamination has become a serious environmental concern that affects terrestrial environments, aquatic ecosystems, and human health. The current study assesses the presence, abundance, and morphology of MPs present in the surface water of Rohtak district, Haryana, India, which is rapidly undergoing industrialization. While the morphological studies of MPs were conducted through stereo microscopy and field emission-scanning electron microscopy (FE-SEM), the elemental composition of polymers was analyzed through attenuated total reflectance-Fourier transform infrared (ATR-FTIR). The results revealed that the surface water was significantly contaminated by polyethylene, polypropylene, and polystyrene. Moreover, the abundance of MPs was found to be 16-28 particles/L with an average value of 23 particles/L. Most of the MPs had fibrous morphology with the specifics being, fibers (43.9%), fragments (23.7%), films (17%), and pellets (15.4%). The MPs exhibited a size range of 0.61-4.87 mm, with an average size measured at 2.03 ± 0.04 mm. Also, the MP pollution load index values for the surface water bodies were found to be below 10, indicating a low risk category. Though currently designated as "low risk," it is important that mitigation strategies be brought over at this juncture to further prevent the deterioration of quality of water. Thus, this study not only intends to bring forth the impact of human activities, industrial waste, open waste dumping, and inadequate municipal waste management practices on increasing MP concentration but also highlights the sustainable alternatives and strategies to address this emerging pollutant in urban water systems. For further prevention, the implementation of stringent regulations and on-site plastic waste segregation is a critical component in preventing the disposal of plastic waste in surface water bodies. RESEARCH HIGHLIGHTS: The abundance of MPs was found to be 16-28 particles/L, with an average value of 23 particles/L. The surface water bodies in Rohtak district fall into the hazard categories of low risk with values less than 10. The overall MP concentration in water, across all five areas, based on color was in order: white/transparent (39.1%), black (15%), gray (9.1%), green (8.7%), blue (7.8%), red (7.8%), orange (6.3%), and yellow (6.1%). The dominant polymers were polyethylene (PE) (42%) and polypropylene (41%) as determined by FTIR spectroscopy.

Co-accumulation characteristics and interaction mechanism of microplastics and PFASs in a large shallow lake.

Microplastics (MPs) and per- and polyfluoroalkyl substances (PFASs) coexist widely in lakes and affect ecological security. The coexistence characteristics and adsorption-desorption mechanisms between MPs and typical PFASs were explored in a typical eutrophic shallow lake (Taihu Lake). Polyvinyl chloride (PVC) and polyethylene (PE) are the primary types of MPs in Taihu Lake, with average abundances in water and sediment of 18630 n/m3 and 584 n/kg, respectively. The average concentrations of PFASs in water and sediment are 288.93 ng/L and 4.33 ng/g, with short-chain PFASs (C4-C7) being the main pollutants. Perfluorobutanoic acid (PFBA) in both water and sediment contributed 38.48 % and 44.53 %, respectively, followed by hexafluoropropylene oxide dimer acid (HFPO-DA). The morphological characteristics of MPs influence the distribution of long-chain PFAS in lake water, while the presence of HFPO-DA and perfluorohexanoic acid (PFHxA) in sediment is directly linked to the concentration and size of MPs. A combination of field investigations and indoor experiments revealed that the irreversible adsorption characteristics between MPs and HFPO-DA may promote the high cumulative flux of HFPO-DA in sediment, and the biofilm on the surface of MPs significantly accelerates this accumulation process. The results provide a new perspective on the co-transport behavior of emerging pollutants in aquatic environments.

Strategies for Removing Endocrine Disrupting Chemicals (EDCs) from Wastewater.

INTRODUCTION: Endocrine-disrupting drugs, also called endocrine disruptors or micropollutants, cause serious environmental and public health problems due to their ability to disrupt the endocrine functions of organisms and humans, even at low concentrations. This report provides a summary of current removal techniques, such as activated sludge processes, membrane filtration, adsorption, and membrane bioreactor techniques for endocrine-disrupting chemicals, including their efficiency, limitations, and practical implementation. METHODS: This review evaluates these methods by considering their treatment efficiency, costs, and environmental impact. To curb this menace, several developed countries have distinct strategies, such as physical remediation techniques, biological processes, phytoremediation, and chemical processes to remove endocrine disruptors. RESULTS: In developing nations, most conventional wastewater treatment plants do not even monitor those contaminants due to the low biodegradability and high complexity of such compounds. CONCLUSION: Hence, in this review work, potential endocrine-disrupting chemicals, their impacts, mechanisms of action, consequences for human health, and bio-mitigation strategies reported so far have been discussed in the context of the relevant literature.

Comprehensive monitoring and prioritizing for contaminants of emerging concern in the Upper Yangtze River, China: An integrated approach.

Contaminants of emerging concern (CECs) in aquatic environments can adversely impact ecosystems and human health even at low concentrations. This study assessed the risk of 162 CECs, including neonicotinoid pesticides, triazine pesticides, carbamate pesticides, psychoactive substances, organophosphate esters, antidepressants, per- and polyfluoroalkyl substances, and antibiotics in 10 drinking water sources and two tributaries (Jialing and Wujiang Rivers) of the Upper Yangtze River in Chongqing, China. Target screening detected 156 CECs at 0.01-2218.2 ng/L, while suspect screening via LC-QTOF-MS identified 64 CECs, with 13 pesticides, 29 pharmaceuticals and personal care products, and 2 industrial chemicals reported for the first time in the Yangtze River Basin. Risk quotient-based ecological risk assessment revealed that 48 CECs posed medium to high risks (RQ > 0.1) to aquatic life, with antibiotics (n = 20) as the main contributors. Non-carcinogenic risks were below negligible levels, but carcinogenic risks from neonicotinoids, triazines, antidepressants, and antibiotics were concerning. A multi-criteria prioritization approach integrating occurrence, physico-chemical properties, and toxicological data ranked 26 CECs as high priority. This study underscores the importance of comprehensive CEC screening in rivers and provides insights for future monitoring and management strategies.

Pharmaceuticals in raw and treated water from drinking water treatment plants nationwide: Insights into their sources and exposure risk assessment.

Due to the large amounts of pharmaceuticals and personal care products (PPCPs) currently being consumed and released into the environment, this study provides a comprehensive analysis of pharmaceutical pollution in both raw and treated water from full-scale drinking water treatment plants nationwide. Our investigation revealed that 30 out of 37 PPCPs were present in raw water with mean concentrations ranging from 0.01-131 ng/L. The raw water sources, surface water (ND - 147 ng/L), subsurface water (ND - 123 ng/L) and reservoir sources (ND - 135 ng/L) exhibited higher mean concentration levels of pharmaceutical residues compared to groundwater sources (ND - 1.89 ng/L). Meanwhile, in treated water, 17 of the 37 analyzed PPCPs were present with carbamazepine, clarithromycin, fluconazole, telmisartan, valsartan, and cotinine being the most common (detection frequency > 40 %), and having mean concentrations of 1.22, 0.12, 3.48, 40.1, 6.36, and 3.73 ng/L, respectively. These findings highlight that, while water treatment processes are effective, there are some persistent compounds that prove challenging to fully eliminate. Using Monte Carlo simulations, risk assessment indicated that most of these compounds are likely to have negligible impact on human health, except for the antihypertensives. Telmisartan was identified as posing the highest ecological risk (RQ > 1), warranting further investigation, and monitoring. The study concludes by prioritizing specific 14 pharmaceuticals, including telmisartan, clarithromycin, lamotrigine, cotinine, lidocaine, tramadol, and others, for future monitoring to safeguard both ecological and human health.

Antibiotic resistant bacteria and antibiotic resistance genes as contaminants of emerging concern: Occurrences, impacts, mitigations and future guidelines.

Antibiotic resistance, driven by the proliferation of antibiotic resistance genes (ARGs) and antibiotic resistance bacteria (ARBs), has emerged as a pressing global health concern. Antimicrobial resistance is exacerbated by the widespread use of antibiotics in agriculture, aquaculture, and human medicine, leading to their accumulation in various environmental compartments such as soil, water, and sediments. The presence of ARGs in the environment, particularly in municipal water, animal husbandry, and hospital environments, poses significant risks to human health, as they can be transferred to potential human pathogens. Current remediation strategies, including the use of pyroligneous acid, coagulants, advanced oxidation, and bioelectrochemical systems, have shown promising results in reducing ARGs and ARBs from soil and water. However, these methods come with their own set of challenges, such as the need for elevated base levels in UV-activated persulfate and the long residence period required for photocatalysts. The future of combating antibiotic resistance lies in the development of standardized monitoring techniques, global collaboration, and the exploration of innovative remediation methods. Emphasis on combination therapies, advanced oxidation processes, and monitoring horizontal gene transfer can pave the way for a comprehensive approach to mitigate the spread of antibiotic resistance in the environment.

Bimetallic Au/Ag coated on In2O3 for the effective removal of emerging organic contaminants under natural sunlight irradiation.

Antibiotics-polluted wastewater, likely causing the spread of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs), can be effectively remediated by photocatalytic degradation driven by endless solar energy. Herein, bimetallic Au/Ag is deposited on In2O3 surface via a one-step sintering process followed by a controllable chemical reduction approach. Under natural sunlight irradiation, the optimal Au/Ag/In2O3 (UGI-1.0) photocatalyst possesses a considerable norfloxacin (NOR) degradation rate constant of 0.013 min-1, which is 3.25, 1.63, and 1.86 times higher than that of In2O3, Ag/In2O3, and Au/In2O3 respectively. The effect of many water characteristics (e.g., humic acid, water bodies, pH values, and coexisting anions) on the photodegradation performance of NOR over UGI-1.0 is investigated. Moreover, other persistent organic pollutants (ofloxacin, phenol, 2,4-dichlorophenol, and rhodamine B) can also be degraded over UGI-1.0, suggesting its universal oxidation capacity. To settle the challenge of powder photocatalyst recovery, the UGI-1.0 photocatalyst is coated on a frosted glass sheet, which exhibits outstanding activity and stability for degrading NOR. The bimetallic Au/Ag deposited on In2O3 promote its photo-absorption, and enhance its photoinduced charge separation and transfer efficiency by serving as electron accepter, leading to the boosted activity of Au/Ag/In2O3 catalysts. Particularly, the cultivation of staphylococcus aureus (S. aureus) and cabbage seeds reveals the efficient toxicity reduction of NOR by photocatalytic degradation and the nontoxic characteristic of UGI-1.0 catalyst. This work unveils the feasibility of UGI-1.0 to remediate real wastewater with the assistance of solar energy.

Presence of emerging organic contaminants and microbial indicators in surface water and groundwater in urban India.

This study presents a first combined assessment of emerging organic contaminants (EOC) and antimicrobial resistance (AMR) indicators in the South Indian city of Bengaluru from multiple sources, addressing a knowledge gap on EOCs and AMR occurrences and relationships in different water sources in urban India. A unique approach in this study was to combine the detection of EOCs with an assessment of the AMR-indicating class 1 integron-integrase gene, intI1. Twenty-five samples collected from groundwater, local surface waters, and tap water imported from the Cauvery Basin were screened for 1499 EOCs. A total of 125 EOCs were detected at concentrations per compound of up to 314 µg/L. Concentrations for a range of contaminants were higher than those previously detected in Indian groundwaters. High concentrations of Per- and polyfluoroalkyl substances (PFAS) were detected with up to 1.8 µg/L in surface water and up to 0.9 µg/L in groundwater. Calculated risk quotients indicated potential AMR development caused by high concentrations of azithromycin, fluconazole, and sulfanilamide in surface waters that have little protection against sewage inflows. Surface waters that have recently undergone environmental restoration (e.g., removing silted bottom layers and enhancing protection against encroachments and sewage inflows) had lower EOC detections and risk of AMR development. Specific EOC detections, e.g., the ubiquitous detection of the sweetener sucralose (in use since ∼2000), indicated recent groundwater recharge and a contribution of imported Cauvery River water for recharge. This study highlights the need for monitoring and water protection, the role of EOCs as potential drivers of AMR, and the success of surface water protection measures to improve freshwater quality.

Emerging hazardous chemicals and biological pollutants in Canadian aquatic systems and remediation approaches: A comprehensive status report.

Emerging contaminants can be natural or synthetic materials, as well as materials of a chemical, or biological origin; these materials are typically not controlled or monitored in the environment. Canada is home to nearly 7 % of the world's renewable water supply and a wide range of different kinds of water systems, including the Great Lake, rivers, canals, gulfs, and estuaries. Although the majority of these pollutants are present in trace amounts (µg/L - ng/L concentrations), several studies have reported their detrimental impact on both human health and the biota. In Canadian aquatic environments, concentrations of pharmaceuticals (as high as 115 µg/L), pesticides (as high as 1.95 µg/L), bioavailable heavy metals like dissolved mercury (as high as 135 ng/L), and hydrocarbon/crude oil spills (as high as 4.5 million liters) have been documented. Biological threats such as genetic materials of the contagious SARS-CoV-2 virus have been reported in the provinces of Québec, Ontario, Saskatchewan and Manitoba provinces, as well as in the Nunavut territory, with a need for more holistic research. These toxins and emerging pollutants are associated with nefarious short and long-term health effects, with the potential for bioaccumulation in the environment. Hence, this Canadian-focused report provides the footprints for water and environmental sustainability, in light of this emerging threat to the environment and society. Several remediation pathways/tools that have been explored by Canadian researchers, existing challenges and prospects are also discussed. The review concludes with preventive measures and strategies for managing the inventory of emerging contaminants in the environment.