Concurrence of antibiotic resistant bacteria (ARB), viruses, pharmaceuticals and personal care products (PPCPs) in ambient waters of Guwahati, India: Urban vulnerability and resilience perspective

Pollution by antimicrobials and antibiotic resistance genes in East Africa: Occurrence, sources, and potential environmental implications

The escalating burden of antimicrobial pollution in East Africa poses severe threats to public health, environmental integrity, and economic stability. Environmental compartments such as soil and water serve as reservoirs for these pollutants such as antimicrobials and antibiotic resistance genes, creating selective pressure that accelerates the emergence of antimicrobial resistance (AMR). These dynamic fosters the proliferation of multidrug-resistant pathogens, or "superbugs," complicating infection management and amplifying health risks in a region already challenged by inadequate healthcare and sanitation infrastructure. Furthermore, pollution by antimicrobials and antibiotic resistance genes critically disrupts ecological processes, such as nutrient cycling and organic matter degradation, diminishing soil fertility, water quality, and agricultural productivity, thereby threatening food security and overall ecological health. Current surveillance efforts, including the Global Antimicrobial Resistance and Use Surveillance System (GLASS) and the East Africa Public Health Laboratory Networking Project (EAPHLNP), have made strides in tracking AMR trends and guiding policy decisions. However, these efforts remain insufficient to address the growing crisis. This study highlights the urgent need for integrated strategies, including stringent antibiotic usage regulations, advanced wastewater treatment technologies, and comprehensive environmental surveillance. Therefore, there is a need to address the intersections of health, agriculture, and environment, to mitigate AMR and its far-reaching consequences to ensure public health safety and sustainability.

Bimetallic nanoparticles as pioneering eco-friendly catalysts for remediation of pharmaceuticals and personal care products (PPCPs)

The persistent presence of Pharmaceuticals and Personal Care Products (PPCPs) in aquatic environments poses a significant risk to both human health and ecosystems, with conventional water treatment methods often unable to effectively remove these contaminants. Recent research has identified bimetallic nanoparticles as a promising and eco-friendly solution for PPCP remediation, owing to their enhanced catalytic properties and the synergistic effects between the metals. This review critically examines the synthesis, characterization, and application of bimetallic nanoparticles for the degradation of PPCPs in water. Key synthetic approaches, particularly green synthesis methods, are explored, emphasizing their ability to control nanoparticle morphology, size, and composition. We highlight the novel catalytic mechanisms employed by bimetallic nanoparticles, including electron transfer, surface reactions, and adsorption processes, which contribute to efficient PPCP removal. Furthermore, the influence of critical factors such as nanoparticle size, composition, and surface functionalization on catalytic efficiency is analyzed. Key findings include the superior performance of bimetallic nanoparticles over monometallic counterparts, with specific emphasis on their ability to degrade a wide range of PPCPs under mild conditions. However, challenges such as scalability, stability, and environmental impact remain. This review also provides insights into the future directions for bimetallic nanoparticle development, stressing the importance of interdisciplinary research and collaborative efforts to optimize their design for large-scale, sustainable water treatment applications. Overall, this work offers a comprehensive understanding of how bimetallic nanoparticles can be optimized for sustainable water treatment solutions, highlighting their potential to mitigate the adverse effects of PPCPs on both ecosystems and public health.

Antibiotic resistance profile of facultative deep-sea psychro-piezophile bacteria from the Arabian Sea and their relation with physicochemical factors

Antibiotic resistance (ABR) is a significant global challenge, with antibiotics from various sources ending up in the ocean and affecting marine life. Profiling ABR in deep-sea bacteria is crucial for understanding the spread of ABR from environmental microbes to clinical pathogen and vice-versa. We evaluated facultative psychro-piezophile deep-sea bacteria from different depths of the Arabian Sea for their resistance to 20 commercial antibiotics. Bacteria from Zone 5 (2000-3000 m) exhibited the highest multiple antibiotic resistance (MAR) index (0.90), identifying it as a significant reservoir of ABR. Zone 1 (5-100 m) isolates (average 20 %) showed the highest resistance to synthetic antibiotics. Zone 3 (500-1000 m) isolates were highly resistant to diverse classes of antibiotics, separating upper (zone 1 and 2 (100-500 m) and deeper sea zones (zone 4 (1000-2000 m) and 5). The identified isolates belong to Bacillus, Niallia, Escherichia, Cytobacillus, and Pseudomonas genera. Additionally, antibiotic resistance genes (ARGs) such as StrB (2 isolates) and SXT integrase (1 isolate) were detected only in Zone 5 isolates. The SulII gene (19 isolates) was present across all zones. PCA analysis revealed a negative correlation between resistance and physicochemical factors (macronutrients like phosphate (PO43-), nitrate (NO3-), nitrite (NO2-), and ammonia (NH3); micronutrient and heavy metals like (iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), nickel (Ni)), aluminium (Al), cadmium (Cd), and chromium (Cr)), except for Phosphate (0.65). Overall, this study is the first to provide valuable insights into the prevalence of ABR using culture-dependent methods and its correlation with physicochemical factors in the deep-sea environments of the Arabian Sea.

Electrochemical Removal Of Doxycycline Hydrochloride with Cerium-Aluminum Catalytic Anode

Doxycycline hydrochloride (DOX) is a widely used broad-spectrum antibiotic that is challenging to degrade, leading to a series of environmental issues. In this study, a bimetallic oxide catalyst was synthesized through hydrothermal calcination followed by annealing. The catalytic carbon cloth anode was fabricated by bonding materials directly onto carbon cloth. Various characterization methods were employed to analyze the surface morphology, composition, and electrochemical properties of the electrodes. The materials exhibited rich surface morphology and exceptional electrochemical surface area. The catalyst primarily consisted of CeO2 and CeAlO3, demonstrating a 93.85 % removal efficiency of DOX within 2 hours under optimized conditions. Even after seven consecutive degradation cycles, the DOX degradation rate remained at 82 %, confirming the remarkable stability of the electrodes. The product distribution generated during the degradation of DOX was identified using LC-MS analysis, and a potential electrochemical degradation mechanism was proposed. Our results indicate that the bimetallic hybrid coordination significantly enhances the catalytic activity and electrochemical stability of the materials. This work offers a novel approach for preparing modified carbon cloth anodes with high catalytic activity and durability, laying a crucial foundation for the efficient degradation of the antibiotic DOX.

β-cyclodextrin polymers as a new sorbent for solid-phase extraction of xenobiotics in Urine

This study systematically assessed the performance of a newly developed solid-phase extraction (SPE) material, cellulose-supported aminated β-cyclodextrin polymer (amine-β-CDP@Cellulose), in determining 44 xenobiotics, encompassing endocrine-disrupting chemicals (EDCs), pharmaceuticals, and food additives in urine samples. The primary objective of the research was to synthesize a new sorbent, optimize the extraction protocol, and elucidate the underlying adsorption and desorption mechanisms. Following optimization, it was observed that amine-β-CDP@Cellulose achieved recoveries ranging from 80 % to 120 % for 28 of the 44 targeted xenobiotics, with only three compounds showing recoveries below 50 %. The superior extraction performance of this novel material can be attributed to the synergistic effects of its structural components: charged functional groups introduced via the cross-linking agent, the hydrophobic cyclodextrin cavity that facilitates inclusion complexation, and abundant hydroxyl groups that enhance adsorption. Additionally, the study included a comparative analysis between amine-β-CDP@Cellulose and commercially available HLB resins. This comparative analysis revealed that the amine-β-CDP@Cellulose method effectively mitigated matrix interferences while maintaining comparable extraction efficiency to the HLB-based method. Collectively, these findings suggest that amine-β-CDP@Cellulose could serve as a sustainable and cost-effective material for extracting xenobiotics from complex matrices.

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.

Acute exposure to environmentally relevant concentrations of pharmaceutical pollutants induces neurobehavioral toxicity in zebrafish (Danio rerio)

Pharmaceutical waste from point and non-point sources enters, persists, or disseminates in the environment and is known as environmentally persistent pharmaceutical pollutants. Understanding the impacts of pharmaceutical pollutants on the environment and health is essential. This study investigates the behavioral impacts of pharmaceutical pollutants on aquatic organisms and delineates the possible nexus of oxidative stress. The male zebrafish were exposed to four major representative pharmaceutical pollutants, viz., acetaminophen, carbamazepine, metformin, and trimethoprim at environmentally relevant concentrations individually as well as in a mixture for seven days. Substantial alterations in social interaction, aggressive nature, novel tank exploration, and light and dark zone preferences were recorded and the degree varied to different pharmaceutical pollutants. The activity of oxidative stress markers, superoxide dismutase, glutathione-S-transferase, and catalase, was found to be suppressed to 66-20%, 42-25%, and 59-20% respectively with the elevated malondialdehyde generation (180-260%) compared to control. The activity level of acetylcholine esterase was found to be increased to 200-500% across all treatment groups. Despite the synergistic impacts of pharmaceutical pollutants on the whole system that could not be ascertained, this comprehensive study highlights their toxicity nature to induce neurobehavioral toxicity in zebrafish through oxidative stress mechanisms and altered cholinergic systems.

Pharmaceuticals and personal care products and heavy metals in the Ganga River, India: Distribution, ecological and human health risk assessment

In the present study, pharmaceuticals and personal care products (PPCPs), endocrine disrupting compounds (EDCs), and heavy metals (HMs), were measured in water and sediment of the Ganga River during summer and winter seasons for two consecutive years. Additionally, this study estimated the ecological and human health risks associated with PPCPs, EDCs, and HMs. HMs detected in the range of not detected (n.d.) to 23.59 μg/L and 0.01-391.44 μg/g in water and sediment samples, respectively. All studied HMs were within the permissible limits, except for As in water, and Cr and Ni in sediment. The geo-accumulation index (Igeo) indicated that Cr (0.71-5.98) and Pb (0.90-3.90) had high Igeo compared to other metals in sediment samples. Pb showed the highest ecological risk, followed by Cd, Co, Ni, Cu, Cr, As, and Zn. The maximum potential ecological risk index was observed at site G8. The hazard index (HI) value for water (0.08-0.89) and sediment (0.02-0.29) intake by adults remained within the acceptable limits, except at sites G8 (1.27) and G9 (1.34) for water intake. However, for children, the HI value was above the acceptable limit for water intake at sites G4 to G13 and for sediment at site G8. Among the studied compounds, metformin, triclosan, triclocarban, diclofenac, and methylparaben were the most abundant compounds present in the Ganga River. PPCPs and EDCs detected in the range of n.d. to 5850.04 ng/L and n.d. to 1080.41 ng/g in water and sediment samples, respectively. The environmental risk assessment identifies the maximum ecological risk in water exhibited by triclocarban followed by 17α-ethinylestradiol (EE2), diclofenac, and triclosan, while in sediment, the maximum ecological risk exhibited by triclocarban, followed by EE2, 17 β-estradiol (E2), triclosan, and diclofenac. However, none of the compounds showed human health risk, except for EE2, E2, and atenolol.

Dam construction alters the traits of health-related microbes along the Yangtze River

Dams, constructed globally for energy production and water conservation, fragment rivers, and modify flow regimes, thereby altering the composition of biological communities and ecosystem functions. Despite the extensive use of dams, few studies have explored their potential health impacts, particularly concerning changes in health-related genes, such as antibiotic resistance genes (ARGs) and virulence factor genes (VFGs), and their hosts (i.e., ARB and potential pathogens). Understanding these health-related effects is crucial because they can impact human health through water quality and pathogen prevalence. In this study, we investigated the planktonic microbial community in the Three Gorges Reservoir (TGR) and adjacent upstream and downstream areas of the Yangtze River during both the dry and wet season. Our metagenomic analysis showed that dam construction significantly decreased the abundance of ARGs, but it had an insignificant effect on VFGs. The observed reduction in ARGs abundance could be mainly attributed to the decrease abundance of the major ARGs carrier - Limnohabitansin the TGR and downstream areas due to high grazing pressure and fitness cost. Conversely, the abundance of microbes carrying VFGs (potential pathogens) remained stable from upstream to the dam reservoir, which may explain the negligible impact on VFG abundance. Overall, our results provide a detailed understanding of the ecological health implications of dam construction in large river ecosystems.

Assessment of occurrence, source appointment, and ecological risks of pharmaceuticals and personal care products in the water-sediment interface of Qiantang River in the Hangzhou region

Pharmaceuticals and personal care products (PPCPs) have received global attention owing to their potential risks to human health and the ecological environment. However, limited research has explored the occurrence and ecological risks of PPCPs in the Qiantang River (QTR). QTR, the largest water system in Zhejiang Province, China, is significantly influenced by human activities. This study investigated the occurrence, distribution, and ecological risks of 10 types of PPCPs in both surface water and sediment within QTR. The findings revealed that the concentrations of PPCPs detected in surface water ranged from 81.26 to 149.45 ng L-1 during the wet season (April) and from 98.66 to 198.55 ng L-1 during the dry season (September). Moreover, in the sediments, PPCP concentration ranged from 63.24 to 80.66 and 72.54 to 75.06 ng per g dw during both wet and dry seasons, respectively. Among the selected PPCPs, triclosan (TCS) exhibited the highest concentration across, different phases and seasons, followed by benzotriazole in surface water. The analysis of sediment-water equilibrium distribution indicated that the diffusion tendency of PPCPs was closely correlated with their molecular weights. Particularly, TCS exhibited dynamic equilibrium between water and sediment. Principal component analysis and positive matrix factorization model results indicated similar pollution sources for the detected PPCPs. The dominant sources of the detected PPCPs were identified as wastewater of electroplating enterprises, discharge from wastewater treatment plants, and domestic sewage. The ecological risk assessment based on the risk quotient method revealed that TCS with the highest detected concentration posed a high risk in surface water and a low risk in sediment across all sampling sites. However, other detected PPCPs showed either no or low risks. Additionally, PPCPs showed a higher ecological risk during the dry season than during the wet season.

Antibiotics removal and antimicrobial resistance control by ozone/peroxymonosulfate-biological activated carbon: A novel treatment process

Biological activated carbon (BAC) is one of the important treatment processes in wastewater and advanced water treatment. However, the BAC process has been reported to have antimicrobial resistance (AMR) risks. In this study, a new BAC-related treatment process was developed to reduce AMR caused by BAC treatment: ozone/peroxymonosulfate-BAC (O3/PMS-BAC). The O3/PMS-BAC showed better treatment performance on the targeted five antibiotics and dissolved organic matter removal than O3-BAC and BAC treatments. The O3/PMS-BAC process had better control over the AMR than the O3-BAC and BAC processes. Specifically, the amount of targeted antibiotic-resistant bacteria in the effluent and biofilm of O3/PMS-BAC was only 0.01-0.03 and 0.11-0.26 times that of the BAC process, respectively. Additionally, the O3/PMS-BAC process removed 1.76 %-62.83 % and 38.14 %-99.27 % more of the targeted ARGs in the effluent and biofilm than the BAC process. The total relative abundance of the targeted 12 ARGs in the O3/PMS-BAC effluent was decreased by 86 % compared to the effluent after BAC treatment. In addition, Proteobacteria and Bacteroidetes were probably the main hosts for transmitting ARGs in this study, and their relative abundance decreased by 9.6 % and 6.0 % in the effluent of the O3/PMS-BAC treatment compared to that in BAC treatment. The relationship analysis revealed that controlling antibiotic discharge was crucial for managing AMR, as antibiotics were closely related to both ARGs and bacteria associated with their emergence. The results showed that the newly developed treatment process could reduce AMR caused by BAC treatment while ensuring effluent quality. Therefore, O3/PMS-BAC is a promising alternative to BAC treatment for future applications.

Unveiling the ecological landscape of bacterial β-lactam resistance in Delhi-national capital region, India: An emerging health concern

Inappropriate antibiotic use not only amplifies the threat of antimicrobial resistance (AMR), moreover exacerbates the spread of resistant bacterial strains and genes in the environment, underscoring the critical need for effective research and interventions. Our aim is to assess the prevalence and resistance characteristics of β-lactam resistant bacteria (BLRB) and β-lactamase resistant bacterial genes (BLRBGs) under various environmental conditions within Delhi NCR, India. Using a culture-dependent method, we isolated 130 BLRB from 75 different environmental samples, including lakes, ponds, the Yamuna River, agricultural soil, aquatic weeds, drains, dumping yards, STPs, and gaushalas. Tests for antibiotic susceptibility were conducted in addition to phenotypic and genotypic identification of BLs and integron genes. The water and sediment samples recorded an average bacterial abundance of 3.6 × 106 CFU/mL and an average ampicillin-resistant bacterial count of 2.2 × 106 CFU/mL, which can be considered a potent reservoir of BLRB and BLRBGs. The majority of the BLRB discovered are opportunistic pathogens from the Bacillus, Aeromonas, Pseudomonas, Enterobacter, Escherichia, and Klebsiella genera, with Multiple Antibiotic Resistance (MAR) index ≥0.2 against a wide variety of β-lactams and β-lactamase (BLs) inhibitor combinations. The antibiotic resistance pattern was similar in the case of bacteria isolated from STPs. Meanwhile, bacteria isolated from other sources were diverse in their antibiotic resistance profile. Interestingly, we discovered that 10 isolates of various origins produce both Extended Spectrum BLs and Metallo BLs, as well as found harboring blaTEM, blaCTX, blaOXA, blaSHV, int-1, and int-3 genes. Enterobacter cloacae (S50/A), a common nosocomial pathogen isolated from Yamuna River sediment samples at Nizamuddin point, possesses three BLRBGs (blaTEM, blaCTX, and blaOXA) and a MAR index of 1.0, which is a major cause for concern. Therefore, identifying the source, origin and dissemination of BLRB and BLRGs in the environment is of the utmost importance for designing effective mitigation approaches to reduce a load of antimicrobial resistance factors in the environmental settings.

Ecological impact of pharmaceutical pollutants and options of river health improvements - A risk analysis-based approach

Pharmaceuticals are one of the emerging pollutants (EPs) in river waters across the world. Due to their toxic effects on aquatic organisms, they have drawn the global attention of the scientific community concerned with river ecosystems. This paper reviews the existing occurrence data for various pharmaceutical pollutants (PPs) reported in river waters in some part of the world and their ecological impacts. Using algae, macroinvertebrates (MI), and fish as biotic indicator groups in water to reflect river health conditions, an attempt has been made to assess the ecological risk due to the presence of PPs in the water environment. After ascertaining the predicted no-effect concentration (PNEC) of PPs for selected groups of aquatic organisms, the risk quotient (RQ) is estimated based on their measured environmental concentration (MEC). When MEC > PNEC and RQ > 1 for any of the biotic indicator, ecologically it is 'high risk' condition. The determination of PNEC uses a minimum assessment factor (AF) of 10 due to uncertainty in data over the no observed effect level (NOEL) or lowest observed effect level (LOEL). Accordingly, MEC 10 times higher than PNEC, (RQ = 10) represents a threshold risk concentration (RCT) beyond which adverse effects may start showing observable manifestations. In the present study, a new classification system of 'high risk' conditions for RQ = 1-10 has been proposed, starting from 'moderately high' to 'severely high'. For RQ > 10, the ecological condition of the river is considered 'impaired'. For river health assessment, in the present study, the whole range of physico-chemical characteristics of river water quality has been divided into three groups based on their ease of measurement and frequency of monitoring. Dissolved oxygen related parameters (DORPs), nutrients (NTs), and EPs. PPs represent EPs in this study. A framework for calculating separate indicator group score (IGS) and the overall river health index (RHI) has been developed to predict indicator group condition (IGC) and river health condition (RHC), respectively. Color-coded hexagonal pictorial forms representing IGC and RHC provide a direct visible perception of the existing aquatic environment and a scientific basis for prioritization of corrective measures in terms of treatment technology selection for river health improvements. The analyses indicate that many rivers across the world are under 'high risk' conditions due to PPs having MEC > PNEC and RQ > 1. Up to RCT, (where RQ = 10), the 'high risk' condition varies from 'moderately high' to 'severely high'. In many instances, RQ is found much more higher than 10, indicating that the ecological condition of river may be considered as 'impaired'. Algae is the most frequently affected group of biotic indicators, followed by MI and fish. A review of treatment methods for selection of appropriate technology to reduce the pollution load, especially PPs from the wastewater streams has been summarized. It appears that constructed wetlands (CWs) are at present the most suitable nature-based solutions, particularly for the developing economies of the world, to reduce the concentrations of PPs within limits to minimize the ecological impacts of pharmaceutical compounds on biotic indicators and restore the river health condition. Some suggestive design guidelines for the CWs have also been presented to initiate the process.

Removal of tetracycline by ultraviolet/sodium percarbonate (UV/SPC)advanced oxidation process in water

Tetracycline (TC) was widely used and frequently detected in various water bodies, where the presence of TC posed a significant threat to the health of aquatic organisms. Furthermore, antibiotics were hardly degraded by biological treatment. Thus, in order to enhance the removal of TC, we proposed the use of a novel ultraviolet/sodium percarbonate (UV/SPC) advanced oxidation process and initiated an in-depth study. The study investigated the influence of oxidant dosage, initial pH, UV intensity, and TC concentration on the removal of TC. The results demonstrated that the UV/SPC system efficiently removed TC, with removal efficiency increasing as the SPC concentration increased. Within the pH range of 3-11, TC degradation exhibited minimal variation, indicating the UV/SPC system's strong adaptability to pH variations. The research on the impact of the water matrix on TC removal revealed that HCO3- had an inhibitory effect on TC degradation, while NO3- promoted TC degradation. Additionally, the presence of free radical species (·OH, ·CO3-, ·O2-) were detected and rate constants for the secondary reactions (k·OH,TC = 6.3 × 109 L mol-1·s-1, k·CO3-,TC = 3.4 × 108 L mol-1·s-1) were calculated, indicating that ·OH exhibited a stronger oxidative performance compared to ·CO3-. This study did not only present a novel strategy via UV/SPC to remove TC but also uncovered the unique role of ·CO3- for contaminant removal.

Industrial waste-based adsorbents as a new trend for removal of water-borne emerging contaminants

Emerging contaminants in wastewater are one of the growing concerns because of their adverse effects on human health and ecosystems. Adsorption technology offers superior performance due to its cost-effectiveness, stability, recyclability, and reliability in maintaining environmental and health standards for toxic pollutants. Despite extensive research on the use of traditional adsorbents to remove emerging contaminants, their expensiveness, lack of selectivity, and complexity of regeneration remain some of the challenges. Industrial wastes viz. blast furnace slag, red mud, and copper slag can be used to develop efficacious adsorbents for the treatment of emerging contaminants in water. Advantages of the use of such industrial wastes include resource utilization, availability, cost-effectiveness, and waste management. Nevertheless, little is known so far about their application, removal efficacy, adsorption mechanisms, and limitations in the treatment of emerging contaminants. A holistic understanding of the application of such unique industrial waste-derived adsorbents in removing emerging contaminants from water is need of the hour to transform this technology from bench-scale to pilot and large-scale applications. This review investigates different water treatment techniques associated with industrial waste-based adsorbents derived from blast furnace slag, red mud, and copper slag. Besides, this review provides important insights into the growing trends of utilizing such novel types of adsorbents to remove emerging contaminants from water with an emphasis on removal efficacy, controlling measures, adsorption mechanisms, advantages, and limitations. The present timely review brings the current state of knowledge into a single reference which could be a strong platform for future research in understanding the latest advancements, decision making, and financial management related to the treatment of wastewater using industrial waste-based adsorbents.

Global landfill leachate characteristics: Occurrences and abundances of environmental contaminants and the microbiome

Landfill leachates are complex mixtures containing very high concentrations of biodegradable and recalcitrant toxic compounds. Understanding the major contaminant components and microbial community signatures in global landfill leachates is crucial for timely decision-making regarding contaminant management and treatment. Therefore, this study analyzed leachate data from 318 landfill sites primarily used for municipal solid waste disposal, focusing on their chemical and microbiological characteristics. The most prevalent and dominant components in landfill leachates are the chemical oxygen demand (COD, 3.7-75.9 × 103 mg/L) and NH4+ (0.03-0.81 × 104 mg/L), followed by salt species such as SO42- (0.03-5.25 × 103 mg/L), Cl- (3.2-7.8 × 103 mg/L), K+ (0.58-4.20 × 103 mg/L), Na+ (1.3-13.0 × 103 mg/L) and Ca2+ (2.35-230.23 × 103 mg/L), which exhibit significant fluctuations. Heavy metals and metalloids are widely distributed in most landfill leachates but at relatively low concentrations (<182.8 mg/L) compared to conventional parameters. Importantly, there is a distinct global variation in the occurrence of emerging environmental contaminants (ECs). Among these compounds, perfluorooctanoic acid (PFOA, 0.02-7.50 × 103 μg/L) of per- and poly-fluoroalkyl substances (PFAS), bisphenol A (BPA, 0.01-33.46 × 103 μg/L) belonged to endocrine-disrupting compounds (EDCs), together with di-ethyltoluamide (DEET, 1.0-1.0 × 103 μg/L) affiliated to pharmaceuticals and personal care products (PPCPs) are the most frequently detected in landfill leachates. Additionally, the microbial community compositions in most leachates are primarily dominated by Proteobacteria, Bacteroidota, Firmicutes, and Chloroflexi, and some of their abundances are correlated with the concentrations of NH4+, NO3-, Cl-, Na+ and Cr. Notably, the leading microbes driving advanced removal of inorganic nitrogen in the treatment systems are Candidatus Brocadia (anammox), denitrifying Thauera, nitrite-oxidizing bacteria Nitrospira, along with ammonia-oxidizing bacteria Nitrosomonas and Nitrosospira. The findings of this work provide a deeper insight into the leachate characteristics and the sustainable management of landfill leachates, especially presenting a snapshot of the global distribution of pollutants and also the microbiome.

Carbon-based materials as efficient adsorbents for the removal of antibiotics: The real contributions of carbon edge sites

Disclosing the effect of edge defects in carbon-based materials on antibiotic removal remains a great challenge. In this study, carbon-based adsorbents (DC-s) with different degrees of edge defects were synthesized on a large scale via a direct calcination of sodium citrate (SC) and their adsorption performance to antibiotics were explored. The experimental results suggested that the edge defects of DC-s samples were the active sites for the adsorption of tetracycline (TC) and norfloxacin (NOR). The adsorption capacity of the optimal sample DC-900 for TC and NOR was 155.8 and 168.0 mg g-1, respectively. Density functional theory (DFT) calculations further revealed that zigzag edge defects rather than armchair edge defects were crucial to the excellent adsorption performance of DC-s samples for antibiotics, and the natures for the difference in the adsorption performance of the two edge defects for antibiotics were their different electronic structures. In addition, DC-900 also showed stable adsorption efficiency for antibiotics in the interferences, dynamic adsorption, and cycle experiments, suggesting its good environmental application potential. This study provides new insight into clarifying the natures of edge defects with carbon-based adsorbents for high-efficiency removal of antibiotics, which may guide the exploration of cost-effective carbon-based adsorbents.

Selection of priority emerging contaminants in surface waters of India, Pakistan, Bangladesh, and Sri Lanka

The challenge of emerging contaminants (ECs) in global surface water bodies and particularly in low- and middle-income countries such as India, Pakistan, Bangladesh, and Sri Lanka, is evident from the literature. The complexity arises from the high costs involved in EC analysis and the extensive list of ECs, which complicates the selection of essential compounds for scientific and regulatory investigations. Consequently, monitoring programs often include ECs that may have minimal significance within a region and do not pose known or suspected ecological or human health risks. This study aims to address this issue by employing a multi-risk assessment approach to identify priority ECs in the surface waters of the aforementioned countries. Through an analysis of occurrence levels and frequency data gathered from published literature, an optimized risk quotient (RQ) was derived. The findings reveal a priority list of 38 compounds that exhibit potential environmental risks and merit consideration in future water quality monitoring programs. Furthermore, the majority of antibiotics in India (12 out of 17) and Pakistan (7 out of 17) exhibit a risk quotient for antimicrobial resistance selection (RQAMR) greater than 1, highlighting the need for devising effective strategies to mitigate the escalation of antibiotic resistance in the environment.

Tracking drugged waters from various sources to drinking water-its persistence, environmental risk assessment, and removal techniques

Pharmaceuticals have become a major concern due to their nature of persistence and accumulation in the environment. Very few studies have been performed relating to its toxicity and ill effects on the aquatic/terrestrial flora and fauna. The typical wastewater and water treatment processes are not efficient enough to get these persistent pollutants treated, and there are hardly any guidelines followed. Most of them do not get fully metabolized and end up in rivers through human excreta and household discharge. Various methods have been adopted with the advancement in technology, sustainable methods are more in demand as they are usually cost-effective, and hardly any toxic by-products are produced. This paper aims to illustrate the concerns related to pharmaceutical contaminants in water, commonly found drugs in the various rivers and their existing guidelines, ill effects of highly detected pharmaceuticals on aquatic flora and fauna, and its removal and remediation techniques putting more emphasis on sustainable processes.

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

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

The presence of antibiotics and multidrug-resistant Staphylococcus aureus reservoir in a low-order stream spring in central Brazil

The disposal of industrial effluents strongly influences low-order streams, which makes them fragile ecosystems that can be impacted by contamination. In central Brazil, the Extrema River spring targets the dumping of pharmaceutical products from the surrounding industries. So, this work aimed to investigate the presence of antibiotics in Extrema River spring samples and the isolation of Staphylococcus aureus, a potential multidrug-resistant bacteria, verifying the antimicrobial resistance profile of these isolates. Three campaigns were carried out in different locals (P1-P3) between October and December 2021, in the dry and rainy seasons. The high-performance liquid chromatography-tandem mass spectrometry (LCMS) approach indicated the presence of sulfamethoxazole (≥ 1 ng/L), metronidazole (< 0.5 ng/L), and chloramphenicol (< 5 ng/L) in the water samples in November (rainy season). S. aureus was isolated in P1 (n = 128), P2 (n = 168), and P3 (n = 36), with greater resistance to trimethoprim-sulfamethoxazole (90%), clindamycin (70%), and gentamicin (60%). The presence of antibiotics in the Extrema River spring may cause S. aureus antibiotic resistance development. The presence of antibiotics and the high percentage of isolated multidrug-resistant S. aureus in the Extrema River spring cause concern and indicate the clandestine dumping of effluents from nearby pharmaceutical industries. Since preserving the springs of low-order streams is important for the environment and public health, we encourage monitoring the wastewater from Extrema River's nearby pharmaceutical industries and preserving the spring of this river.

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

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

Biological and synthetic surfactant exposure increases antimicrobial gene occurrence in a freshwater mixed microbial biofilm environment

Aquatic habitats are particularly susceptible to chemical pollution, such as antimicrobials, from domestic, agricultural, and industrial sources. This has led to the rapid increase of antimicrobial resistance (AMR) gene prevalence. Alternate approaches to counteract pathogenic bacteria are in development including synthetic and biological surfactants such as sodium dodecyl sulfate (SDS) and rhamnolipids. In the aquatic environment, these surfactants may be present as pollutants with the potential to affect biofilm formation and AMR gene occurrence. We tested the effects of rhamnolipid and SDS on aquatic biofilms in a freshwater stream in Northern Ireland. We grew biofilms on contaminant exposure substrates deployed within the stream over 4 weeks. We then extracted DNA and carried out shotgun sequencing using a MinION portable sequencer to determine microbial community composition, with 16S rRNA analyses (64,678 classifiable reads identified), and AMR gene occurrence (81 instances of AMR genes over 9 AMR gene classes) through a metagenomic analysis. There were no significant changes in community composition within all systems; however, biofilm exposed to rhamnolipid had a greater number of unique taxa as compared to SDS treatments and controls. AMR gene prevalence was higher in surfactant-treated biofilms, although not significant, with biofilm exposed to rhamnolipids having the highest presence of AMR genes and classes compared to the control or SDS treatments. Our results suggest that the presence of rhamnolipid encourages an increase in the prevalence of AMR genes in biofilms produced in mixed-use water bodies.

Removal performance, biotransformation pathways and products of sulfamethoxazole in vertical subsurface flow constructed wetlands with different substrates

For decades, sulfamethoxazole (SMX) has been frequently detected in the aquatic environments due to its high usage and refractory to degradation. Constructed wetland (CW) is regarded as an efficient advanced wastewater technology to eliminate organic pollutants including SMX. In CW system, substrate adsorption and further biodegradation are extremely important in SMX removal; however, the removal performance of SMX by CWs with different substrates varies greatly, and the biotransformation pathways, products, and mechanisms of SMX remain unclear. To address this, we constructed a CW with conventional substrate (CS, gravel) as control (C-CW) and three CWs with emerging substrates (ES, biochar, zeolite and pyrite for B-CW, Z-CW and P-CW, respectively), and explored the performance and mechanisms of SMX removal in CWs. Results illustrated that the removal performance of SMX in CWs with ES reached 94.89-99.35%, and significantly higher than that with CS of 89.50% (p < 0.05). Biodegradation contributed >90% SMX removal in all CWs. The microbial compositions and functions differed among CWs at the middle layer (mixed layer), which shaped diverse resistance pattern and metabolism pathways of microbiomes under SMX stress: P-CW and B-CW cope with SMX stress by enhancing material and energy metabolism, whereas Z-CW does that by enhancing metabolism and exocytosis of xenobiotics. Additionally, nine transformation pathways with 15 transformation products were detected in this study. A reversible process of desamino-SMX being reconverted to SMX might exist in P-CW, which caused a lower SMX removal efficiency in P-CW. This study provided a comprehensive insight into the processes and mechanisms of SMX removal in CWs with different substrates, which would be a useful guidance for substrate selection in CWs in terms of enhanced micropollutants removal.

Sustainable conversion of antibiotic wastewater using microbial fuel cells: Energy harvesting and resistance mechanism analysis

In this study, tetracycline (TC) can be degraded in microbial fuel cells (MFCs) rapidly and efficiently for the synergistic effect of microbial metabolism and electrical stimulation. Different TC concentrations had different effects on the bioelectric performance of MFCs. Among them, 10 mg/L TC promoted the bioelectric properties of MFCs, the maximum power density reached 1744.4 ± 74.9 mW/cm². In addition, we demonstrated that Geobacter and Chryseobacterium were the dominant species in the anode biofilm, while Azoarcus and Pseudomonas were the prominent species in the effluent, and the initial TC concentration affected the microbial community composition. Furthermore, the addition of TC increased the relative abundance of aadA3, sul1, adeF, cmlA, and tetC in reactors, indicating that a single antibiotic could promote the expression of self-related resistance as well as the expression of other ARGs. Moreover, the presence of TC can increase the relative content of mobile genetic elements (MGEs) and greatly increase the risk of antibiotic resistance genes (ARGs) spreading. Meanwhile, network analysis revealed that some microorganisms (such as Acidovorax caeni, Geobacter soil, and Pseudomonas thermotolerans) and MGEs may be potential hosts for multiple ARGs.

Adsorptive removal of pharmaceutically active compounds from multicomponent system using Azadirachta indica induced zinc oxide nanoparticles: analysis of competitive and cooperative adsorption

In this research, zinc oxide (ZnO) nanoparticles synthesized using neem leaf (Azadirachta indica) extract were used as an adsorbent for removing two widely used pharmaceutical compounds acetaminophen (AMP) and sulfadiazine (SDZ). The synthesized ZnO nanoparticles were characterized using SEM-EDS, FTIR, TEM, BET, and XRD analysis. The synthesized ZnO nanoparticles were found to be in the size range of 10 nm with a surface area of 48.551 m²/g. The adsorptive performance of ZnO nanoparticles in both mono-component (MoS) and multi-component system (MuS) was investigated under various operational parameters viz. contact time, temperature, pH, concentration of pharmaceutical compound and ZnO nanoparticles dose. It was observed that the maximum adsorption capacity of ZnO nanoparticles was 7.87 mg/g and 7.77 mg/g for AMP and SDZ, respectively, under the optimum conditions of 7 pH and 2 g/L adsorbent dosage. The experimental data best-fitted with the pseudo-second-order model and Langmuir model, indicating monolayer chemisorption. Further investigation on removal of AMP and SDZ from multicomponent system was modelled using a Langmuir competitive model. The desorption study has shown 25.28% and 22.4% removal of AMP and SDZ from the surface of ZnO nanoparticles. In general, green synthesized ZnO nanoparticles can be utilized effectively as adsorbent for removal of pharmaceutically active compounds from wastewater.

Modern knowledge-scape possess petite influence on the factual persistence of resistance determinants (ARGs/MGEs): A map and assessment of discharged wastewater and water bodies

Antibiotic resistance genes (ARGs) and Mobile genetic elements (MGEs) are major global emerging pollutants of the environment and water nexus which various investigators of related studies have reported. Observing ARGs and MGEs in water bodies, wastewater treatment systems, and estuaries is indicative of relevant risk, resistant bacteria/ARGs spread or potential health concern and may result environmental pathogen bloom if appropriate research-based strategies are not implemented to remove these lethal genetic materials. Despite reports and knowledge-based strategies for removal, the challenge yet persists. This study aims to appraise the impact/contribution of related studies and emphasize the necessity for applying combined research-based/practitioners approach in addressing the expanding challenge of ARGs/MGEs in wastewater/waterbodies. The study describes a bibliometric assessment of antibiotic resistance determinants annual scientific publications on the Web of Science, an annual growth rate of related articles, top articles per citations with search topics and content-review analysis to evaluate the methods of removal of ARGs/MGEs. A total of 1301 articles of wastewater treatment systems were retrieved with date range of 1997-2019. A description of the study Annual Growth Rate of 37.82% at R² of 0.7863 was observed with an increasing article publication and a decreasing total citation rate indicating persistent reports of dispersion on ARGs/MGEs studies in the water bodies and environment. Although there abound extensive studies and reports of ARGs and MGEs in water nexus and wastewater release with research based removal strategies, the impact of such reports have not been fully actualized amongst wastewater system practitioners. A lucid drive towards implementing ARGs/MGEs removal strategies from the environment by applying affirmed research-based methods are suggestive.

The screening of emerging micropollutants in wastewater in Sol Plaatje Municipality, Northern Cape, South Africa

Although pollutants pose environmental and human health risks, the majority are not routinely monitored and regulated. Organic pollutants emanate from a variety of sources, and can be classified depending on their chemistry and environmental fate. Classification of pollutants is important because it informs fate processes and apposite removal technologies. The occurrence of emerging contaminants (ECs) in water bodies is a source of environmental and human health concern globally. Despite being widely reported, data on the occurrence of ECs in South Africa are scarce. Specifically, ECS in wastewater in the Northern Cape in South Africa are understudied. In this study, various ECs were screened in water samples collected from three wastewater treatment plants (WWTPs) in the province. The ECs were detected using liquid chromatography coupled to high resolution Orbitrap mass spectrometry following Oasis HLB solid-phase extraction. The main findings were: (1) there is a wide variety of ECs in the WWTPs, (2) physico-chemical properties such as pH, total dissolved solids, conductivity, and dissolved organic content showed reduced values in the outlet compared to the inlet which confirms the presence of less contaminants in the treated wastewater, (3) specific ultraviolet absorbance of less than 2 was observed in the WWTPs samples, suggesting the presence of natural organic matter (NOM) that is predominantly non-humic in nature, (4) most of the ECs were recalcitrant to the treatment processes, (5) pesticides, recreational drugs, and analgesics constitute a significant proportion of pollutants in wastewater, and (6) NOM removal ranged between 35 and 90%. Consequently, a comprehensive database of ECs in wastewater in Sol Plaatje Municipality was created. Since the detected ECs pose ecotoxicological risks, there is a need to monitor and quantify ECs in WWTPs. These data are useful in selecting suitable monitoring and control strategies at WWTPs.

Updated knowledge, partitioning and ecological risk of pharmaceuticals and personal care products in global aquatic environments

Over the last few decades, the occurrence of pharmaceuticals and personal care products (PPCPs) in aquatic environments has generated increasing public concern. In this review, data on the presence of PPCPs in environmental compartments from the past few years (2014-2022) are summarized by carrying out a critical survey of the partitioning among water, sediment, and aquatic organisms. From the available articles on PPCP occurrence in the environment, in Web of Science and Scopus databases, 185 articles were evaluated. Diclofenac, carbamazepine, caffeine, ibuprofen, ciprofloxacin, and sulfamethoxazole were reported to occur in 85% of the studies in at least one of the mentioned matrices. Risk assessment showed a moderate to high environmental risk for these compounds worldwide. Moreover, bioconcentration factors showed that sulfamethoxazole and trimethoprim can bioaccumulate in aquatic organisms, while ciprofloxacin and triclosan present bioaccumulation potential. Regarding spatial distribution, the Asian and European continents presented most studies on the occurrence and effects of PPCPs on the environment, while Africa and Asia are the most contaminated continents. In addition, the impact of COVID-19 on environmental contamination by PPCPs is discussed.

Ring defects-rich and pyridinic N-doped graphene aerogel as floating adsorbent for efficient removal of tetracycline: Evidence from NEXAFS measurements and theoretical calculations

The rational design of carbon-based adsorbents with a high uptake efficiency for polar organic molecules is a key challenge in water purification research. Herein, we report a graphene aerogel that is doped with pyridinic-N and has abundant ring defects (denoted by DNGA). The aerogel sample exhibits a high adsorption capacity of 607.1 mg/g toward tetracycline (TC), a fast adsorption process (20 min), and good reusability (with a declining efficiency < 10.0% after five cycles), while being easy to recycle. C/N K-edge X-ray absorption near-edge structure (XANES) measurements demonstrate that the efficient adsorption capacity of the DNGA sample is related to the presence of ring defects and the pyridinic-N species. Density functional theory (DFT) calculations demonstrate that ring defects of type 5-8-5 and the pyridinic-N species at the edge location are primarily responsible for TC removal. In this study, we resolve a controversial issue regarding the origin of the adsorption performance origin of N-doped carbon-based adsorbents. The findings of this study can guide the development of novel and improved N-doped carbon-based adsorbents for the removal of target contaminants.

Spent waste from edible mushrooms offers innovative strategies for the remediation of persistent organic micropollutants: A review

Urgent and innovative strategies for removal of persistent organic micropollutants (OMPs) in soil, groundwater, and surface water are the need of the hour. OMPs detected in contaminated soils and effluents from wastewater treatment plants (WWTPs) are categorized as environmentally persistent pharmaceutical pollutants (EPPPs), and endocrine disrupting chemicals (EDCs), their admixture could cause serious ecological issues to the non-target species. As complete eradication of OMPs is not possible with the extant conventional WWTPs technology, the inordinate and reckless application of OMPs negatively impacts environmental regenerative and resilience capacity. Therefore, the cardinal focus of this review is the bioremediation of persistent OMPs through efficient application of an agro-waste, i.e. spent mushroom waste (SMW). This innovative, green, long-term strategy embedded in the circular economy, based on state of the art information is comprehensively assessed in this paper. SMW accrues ligninolytic enzymes such as laccase and peroxidase, with efficient mechanism to facilitate biodegradation of recalcitrant organic pollutants. It is vital in this context that future research should address immobilization of such enzymes to overcome quantitative and qualitative issues obstructing their widespread use in biodegradation. Therefore, dual benefit is gained from cultivating critical cash crops like mushrooms to meet the escalating demand for food resources and to aid in biodegradation. Hence, mushroom cultivation has positive environmental, social, and economic implications in developing countries like India.

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

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

Emerging pharma residue contaminants: Occurrence, monitoring, risk and fate assessment - A challenge to water resource management

Water is one of the important gifts to mankind. In recent days the accessibility of pharmaceuticals in the environment is progressively a worldwide concern. The significant wellspring of these contaminations in water assets is drugs for human use or veterinary medications. Intermediates, active metabolites and raw materials present in water from pharmaceutical industry waste because of incomplete sewage treatment systems. Various pharmaceutical components such as analgesic/antipyretics such as Ibuprofen (57.9-104 ng/L), Diclofenac (17-129 ng/L), antibiotics such as Sulfamethoxazole (28.7-124.5 ng/L), Sulfamethazine (29.2-83.9 ng/L), Azithromycin (10-68 ng/L), psychiatric drug such as Carbamazepine (9.3-92.4 ng/L), stimulants such as caffeine greater than 55 ng/L, antidepressants, antihypertensive, contraceptives etc., are present in water resources and have been detected in mg/L to μg/L range. The synergic effects and ecotoxicological hazard assessment must be developed. Studies demonstrate that these drugs might cause morphological, metabolic and sex alterations on sea-going species, and interruption of biodegradation activities. Hazard analysis and assessments are in progress. However, the conventional effluent treatment methods are not sufficient to remove API (active pharmaceutical ingredients) from this water effectively. There is necessitate for continuous monitoring of the pharmaceutical compounds in aquatic ecosystem to save the environment and living form of lives from health hazards. This work highlights the hazards, environmental assessment and the mitigation measures of pharmaceutical pollutants.

Monsoon dilutes the concurrence but increases the correlation of viruses and Pharmaceuticals and Personal Care Products (PPCPs) in the urban waters of Guwahati, India: The context of pandemic viruses

Concurrence of pharmaceuticals and personal care products (PPCPs), pathogenic viruses, metals and microbial pollution along with their seasonal variations in the water environment are overarching in the context of existing pandemic, especially for tropical countries. The present study focuses on the seasonal influence on the vulnerability of urban water in Guwahati, the largest city in North-eastern India, through examining the concurrence of seven PPCPs, five viruses, faecal bacteria and nine metals in surface waters during monsoon (Summer-July 2017) and pre-monsoon (Winter-March 2018). Surface water sampling was carried out at different locations of the Brahmaputra River, its tributary Bharalu River (an unlined urban drain), and Dipor Bill Lake (Ramsar-recognized wetland). Both PPCPs and viruses were at high concentrations (e.g. up to 970 ng L^-1 caffeine, 2.5 × 10³ copies mL^-1 pepper mild mottle virus (PMMoV)) at the confluence points of urban drains and the river, while they were mostly undetectable at both upstream and downstream locations, implying strong self-purification ability of the river. All the analysed PPCPs and viruses were at much higher concentrations during pre-monsoon i.e., winter than during monsoon, implying heavy dilution and temperature effect during the monsoon. Overall, PPCPs and viruses were more correlated in monsoon but the risk quotient in the urban tributary was higher in pre-monsoon (e.g. 5061 in pre-monsoon and 1515 in monsoon for caffeine). PMMoV was found to be an excellent faecal pollution indicator due to its prevalence, detectability and specificity in all seasons. Overall, the seasonal fluctuations of the non-enveloped viruses monitored in this study is likely to be relevant for SARS-CoV-2. We contribute to address the literature scarcity pertaining to seasonal variations in the prevalence of viruses and their concurrences with contaminants of emerging concern.

Characteristics of Antibiotic Resistance Genes and Antibiotic-Resistant Bacteria in Full-Scale Drinking Water Treatment System Using Metagenomics and Culturing

The contamination of antibiotic resistance genes (ARGs) may directly threaten human health. This study used a metagenomic approach to investigate the ARG profile in a drinking water treatment system (DWTS) in south China. In total, 317 ARG subtypes were detected; specifically, genes encoding bacitracin, multidrug, and sulfonamide were widely detected in the DWTS. Putative ARG hosts included Acidovorax (6.0%), Polynucleobacter (4.3%), Pseudomonas (3.4%), Escherichia (1.7%), and Klebsiella (1.5%) as the enriched biomarkers in the DWTS, which mainly carried bacitracin, beta-lactam, and aminoglycoside ARGs. From a further analysis of ARG-carrying contigs (ACCs), Stenotrophomonas maltophilia and Pseudomonas aeruginosa were the most common pathogens among the 49 ACC pathogens in the DWTS. The metagenomic binning results demonstrated that 33 high-quality metagenome-assembled genomes (MAGs) were discovered in the DWTS; particularly, the MAG identified as S. maltophilia-like (bin.195) harbored the greatest number of ARG subtypes (n = 8), namely, multidrug (n = 6; smeD, semE, multidrug_transporter, mexE, semB, and smeC), beta-lactam (n = 1; metallo-beta-lactamase), and aminoglycoside [n = 1; aph(3’)-IIb]. The strong positive correlation between MGEs and ARG subtypes revealed a high ARG dissemination risk in the DWTS. Based on the pure-culture method, 93 isolates that belong to 30 genera were recovered from the DWTS. Specifically, multidrug-resistant pathogens and opportunistic pathogens such as P. aeruginosa, Bacillus cereus, and S. maltophilia were detected in the DWTS. These insights into the DWTS’s antibiotic resistome indicated the need for more comprehensive ARG monitoring and management in the DWTS. Furthermore, more effective disinfection methods need to be developed to remove ARGs in DWTSs, and these findings could assist governing bodies in the surveillance of antibiotic resistance in DWTSs.

Spectre of SARS-CoV-2 RNA in the ambient urban waters of Ahmedabad and Guwahati: A tale of two Indian cities

COVID-19 positive patients can egest live SARS-CoV-2 virus and viral genome fragments through faecal matter and urine, raising concerns about viral transmission through the faecal-oral route and/or contaminated aerosolized water. These concerns are amplified in many low- and middle-income countries, where raw sewage is often discharged into surface waterways and open defecation is common. Nonetheless, there has been no evidence of COVID-19 transmission via ambient urban water, and the virus viability in such aquatic matrices is believed to be minimal and not a matter of concern. In this manuscript, we attempt to discern the presence of SARS-CoV-2 genetic material (ORF-1ab, N and S genes) in the urban water (lakes, rivers, and drains) of the two Indian cities viz., Ahmedabad (AMD), in western India with 9 wastewater treatment plants (WWTPs) and Guwahati (GHY), in the north-east of the country with no such treatment facilities. The present study was carried out to establish the applicability of environmental water surveillance (E-wat-Surveillance) of COVID-19 as a potential tool for public health monitoring at the community level. 25.8% and 20% of the urban water samples had detectable SARS-CoV-2 RNA load in AMD and GHY, respectively. N-gene > S-gene > ORF-1ab-gene were readily detected in the urban surface water of AMD, whereas no such observable trend was noticed in the case of GHY. The high concentrations of SARS-CoV-2 genes (e.g., ORF-1ab; 800 copies/L for Sabarmati River, AMD and S-gene; 565 copies/L for Bharalu urban river, GHY) found in urban waters suggest that WWTPs do not always completely remove the virus genetic material and that E-wat-Surveillance of COVID-19 in cities/rural areas with poor sanitation is possible.

Human health and ecological risk assessment of 98 pharmaceuticals and personal care products (PPCPs) detected in Indian surface and wastewaters

The release of pharmaceuticals and personal care products (PPCPs) in environmental waters has become an urgent issue due to their pseudo-persistent traits. The present study was undertaken to conduct a screening-level risk assessment of 98 PPCPs, detected in different water matrices (treated wastewater, surface water, and groundwater) of India, for evaluating ecological risk (risk to fish, daphnia, and algae), human health risk, and antimicrobial resistance (AMR) selection risk by following risk quotient (RQ) based methodology. In the present study, 47% of the detected PPCPs in Indian waters were found to exert a possible risk (RQ > 1) to either aquatic species and human health, or cause AMR selection risk. 17 out of 25 antibiotics detected in the environmental waters were found to pose a threat of AMR selection. 11 out of 49 pharmaceuticals were found to exert human health risk from ingesting contaminated surface water, whereas only 2 pharmaceuticals out of 25 were found to exert risk from the intake of groundwater. Very high RQs (>1000) for few pharmaceuticals were obtained, signifying a great potential of the detected PPCPs in causing severe health concern, aquatic toxicity, and AMR spread. Within India, special attention needs to be given to the pharmaceutical hubs, as the environmental waters in these regions were found to be severely contaminated with drug residues resulting in extremely high RQs. The present study will be helpful in prioritizing the detected PPCPs in the environmental waters of India, for which immediate attention and enforceable guidelines are required.

Transmission risk of SARS-CoV-2 in the watershed triggered by domestic wastewater discharge

The outbreak of COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has already become an unprecedented global pandemic. However, the transmission of SARS-CoV-2, especially the protected SARS-CoV-2 RNA (pRNA) with infectious particles in waterways, is still largely unexplored. In this study, we developed a model to estimate SARS-CoV-2 transmission from the risk source in the excretion of patients to the final exposure in surface water. The model simulated the spatial and temporal distribution of the viral pRNA concentrations in the surface water of the Elbe watershed from March 2020 to January 2021. The results show that the WWTPs with the maximum capacity of >10,000 population equivalents were responsible for 95% of the viral load discharged into the surface water. We estimated the pRNA concentrations in surface water to be 1.33 × 10-2 copies·L-1 on average in the watershed based on the model simulation on viral transmission. It had considerable variations in spatial and temporal scales, which are dominantly controlled by epidemic situations and virus transport with decay in water, respectively. A quantitative microbial risk assessment was conducted to estimate the viral infection probability from surface water ingestion with consideration of the influence of toilet usage frequency and gender/age population groups. All the infection probabilities in the study period were lower than the reference risk levels of 10-4 and 10-5. The individuals aged 15-34 years had the highest infection probability of 4.86 × 10-9 on average from surface water ingestion during swimming activities. The data provided herein suggest that the low pRNA concentrations and infection probability reflected that the waterways were unlikely to be a significant transmission route for SARS-CoV-2.

Lycopene attenuates oxidative stress, inflammation, and apoptosis by modulating Nrf2/NF-κB balance in sulfamethoxazole-induced neurotoxicity in grass carp (Ctenopharyngodon Idella)

All drugs that can penetrate the blood-brain barrier (BBB) may lead to mental state changes, including the widely used anti-infective drug sulfamethoxazole (SMZ). Herein, we investigated whether lycopene (LYC) could ameliorate SMZ-induced brain injury and the postulated mechanisms involved. A total of 120 grass carps were exposed under SMZ (0.3 μg/L, waterborne) or LYC (10 mg/kg fish weight, diet) or their combination for 30 days. Firstly, brain injury induced by SMZ exposure was suggested by the damage of BBB (decreases of Claudins, Occludin and Zonula Occludens), and the decrease of neurotransmitter activity (AChE). Through inducing oxidative stress (elevations of malondialdehyde and 8-hydroxy-2 deoxyguanosine, inhibition of glutathione), SMZ increased the intra-nuclear level of NF-κB and its target genes (TNF-α and interleukins), creating an inflammatory microenvironment. As a positive feed-back mechanism, apoptosis begins with activation of pro-death proteins (Bax/Bcl-2) and activation of caspases (caspase-9 and caspase-3). Meanwhile, a compensatory upregulation of constitutive Nrf2 and its downstream antioxidative gene expression (NAD(P)H Quinone Dehydrogenase 1 and Heme oxygenase 1) and accelerated autophagy (increases of autophagy-related genes and p62 inhibition) were activated as a defense mechanism. Intriguingly, under SMZ stress, LYC co-administration decreased NF-κB/apoptosis cascades and restored Nrf2/autophagy levels. The neuroprotective roles of LYC make this natural compound a valuable agent for prevention SMZ stress in environment. This study suggests that LYC might be developed as a potential candidate for alleviating environmental SMZ stress in aquaculture.

Adsorption and detoxification of pharmaceutical compounds from wastewater using nanomaterials: A review on mechanism, kinetics, valorization and circular economy

Antibiotics overuse, inappropriate conduct, and discharge have led to adverse effects on various ecosystems. The occurrence of antibiotics in surface and drinking water is a matter of global concern. It is responsible for multiple disorders, including disruption of endocrine hormones and high chronic toxicity. The hospitals, pharmaceutical industries, households, cattle farms, and aquaculture are the primary discharging sources of antibiotics into the environment. This review provides complete detail on applying different nanomaterials or nanoparticles for the efficient removal of antibiotics from the diverse ecosystem with a broader perspective. Efforts have been made to focus on the degradation pathways and mechanism of antibiotic degradation using nanomaterials. More light has been shed on applying nanostructures in photocatalysis, which would be an economical and efficient solution. The nanoscale material or nanoparticles have incredible potential for mineralizing pharmaceutical compounds in aqueous solutions at low cost, easy handling characteristics, and high efficacy. Furthermore, nanoparticles can absorb the pharmaceutical by-products and wastes at a minimum cost as they can be easily recycled. With the increasing number of research in this direction, the valorization of pharmaceutical wastes and by-products will continue to expand as we progress from old conventional approaches towards nanotechnology. The utilization of nanomaterials in pharmaceutical wastewater remediation is discussed with a major focus on valorization, energy generation, and minimization and its role in the circular economy creating sustainable development.

Emerging contaminants in Brazilian aquatic environment: identifying targets of potential concern based on occurrence and ecological risk

Although studies have shown the presence of Contaminants of Emerging Concern (CECs) in the Brazilian environment in recent decades, several biological effects on the aquatic ecosystem are unknown. Brazil is the fifth largest country in extension in the world, and its wide territory presents geographic regions with diverse demographic and economic characteristics. In order to identify targets of potential concern based on occurrence and ecological risk, available data from previous studies were examined to conduct environmental risk analysis and provide a ranking of CECs in Brazilian aquatic environment based on environmental concentration measured in the last 10 years. The results indicate that 17α-ethynylestradiol, 17ß-estradiol, acetaminophen, Bisphenol A, caffeine, diclofenac, ibuprofen, methylparaben, sulfamethoxazole and triclosan are the CECs that represent the greatest threats to the Brazilian environment. Therefore, these contaminants should be considered as a priority in future monitoring studies. Besides, identification of target monitoring compounds can facilitate the selection of pollutant candidates in future legislations.

Distribution of pharmaceutical and personal care products (PPCPs) in aquatic environment in Hanoi and Metro Manila

Pharmaceutical and personal care products (PPCPs) recently defined as emerging pollutants that widespread in surface water all around the world. This study investigated the distribution, and ecological risk of PPCPs in urban rivers of Hanoi, Vietnam, and Metro Manila, the Philippines. Of the 56 investigated PPCPs, 48 and 33 compounds were detected in the river water in Hanoi and in Metro Manila, respectively. The individual PPCP concentrations ranged from a few ng L^-1 to thousands of ng L^-1_. The total concentration of PPCPs detected in water samples ranged from 7.5 to 20,789 ng L^-1 in Hanoi and 118 to 3,394 ng L^-1 in Manila. The predominant antibiotics was sulfamethoxazole detected in 27/28 samples with a maximum concentration up to 2,778 ng L^-1 in Hanoi and presented in all samples with a maximum concentration up to 261 ng L^-1 in Metro Manila. In Hanoi, the level of PPCPs in urban canals of Kim Nguu and To Lich Rivers was as high as that detected in domestic wastewater. The PPCP concentrations in tributaries and mainstream were lower than those found in urban canals. In rivers of both sites, PPCPs tended to increase along the stream. The concentration ratio of the labile marker caffeine to recalcitrant marker carbamazepine indicated that untreated domestic wastewater is the significant source of PPCPs in river water in Hanoi and Metro Manila. The ecological risk estimated by the risk quotient of the obtained maximum residue of PPCPs in investigated river water predicted a high risk of PPCPs to the aquatic organism in both Hanoi and Manila.

Initial behaviors and removal of extracellular plasmid gene in membrane bioreactor

Extracellular antibiotic resistance genes (eARG) are considered to play an important role in spread of antimicrobial resistance (AMR) in wastewater treatment and water environment. Membrane bioreactor (MBR) reportedly has better removal of ARGs in wastewater than conventional activated sludge process. However, removal of eARG is possibly limited because eARG is small to pass through microfiltration (MF) membranes. To evaluate potential removal of eARG in MBR, this study aimed to understand the initial behaviors of eARG received in MBR. The recombinant plasmid with artificial marker gene was spiked in lab-scale MBR to trace fate of eARG in MBR. Among 10 ¹⁰ copies/L of the spiked gene, 2.6 × 10⁹ copies/L was adsorbed on sludge particles at 6 h after spiking, while only 2.2 × 10⁸-3.6 × 10⁸ copies/L of the spiked gene was remained but constant in sludge liquid phase from 6 until 48 h. This result suggests that adsorption on sludge particles served as the main mechanism to govern the initial fate of eARG in MBR. Meanwhile, the spiked gene concentrations in membrane permeate was lower than sludge liquid phase and decreased overtime, suggesting retention of eARG in membrane filtration. Total LRV of the spiked extracellular gene were 3.4 ± 0.8 log at 48 h after spiking. LRV by adsorption corresponded to 1.7 ± 0.7 log constantly since 3 h after spiking, while LRV by membrane filtration increased from 0 to 1.7 ± 0.6 log. Linear correlation of LRV by membrane filtration with transmembrane pressure (TMP) suggested that foulant deposition on membrane governs removal of eARG by membrane filtration in MBR.

Integrated use of inverse and biotic ligand modelling for lake water quality resilience estimation: A case of Ramsar wetland, (Deepor Beel), Assam, India

The present study evaluates the vulnerability of the lake system (Deepor Beel) due to the combined exposure of toxic metals, major ions and mineral dissociation. The hydro-chemistry of the Deepor Beel lake reveals the dominance of carbonate weathering with strong evidences of ion-exchange reaction occurring throughout the monsoon season of 2014 and 2015. Through an integrated application of multivariate analysis, the occurrence of albite weathering was confirmed, although as an isolated incidence only, along-with substantial evidence of waste water intrusion from fertilizer industries. The moderate cation exchange capacity (CEC) of the soil, indicates the presence of illite, chlorite and kaolinite which provides a strong buffering action in terms of phosphorous and nutrient retention. However, occurrences of chemical waste in the form of bleaching powder (Ca(OCl)₂) are causing acidification of lake soil, which will trigger the release of phosphorous and may enhance the eutrophication level in near future. Through the simulations of Biotic Ligand (BL) model on ceriodaphnia dubia, it is being revealed, that the free availability of Ca²⁺ in the lake water, provides a higher adsorptive competition for labile metal species especially for Cu and Zn. Additionally, the risk among children from drinking lake water, has increased by three to seven times in a duration of just one year. The present study is a pioneering work, which has evaluated the vulnerability of Deepor Beel lake by adopting a sequential assessment strategy of lake internal as well as external ecology. Our proposed methodology can be a used as a scientific basis for future assessment of the lake health.

Diversity of Multidrug-Resistant Bacteria in an Urbanized River: A Case Study of the Potential Risks from Combined Sewage Overflows

Wastewater contamination and urbanization contribute to the spread of antibiotic resistance in aquatic environments. This is a particular concern in areas receiving chronic pollution of untreated waste via combined sewer overflow (CSO) events. The goal of this study was to expand knowledge of CSO impacts, with a specific focus on multidrug resistance. We sampled a CSO-impacted segment of the James River (Virginia, USA) during both clear weather and an active overflow event and compared it to an unimpacted upstream site. Bacteria resistant to ampicillin, streptomycin, and tetracycline were isolated from all samples. Ampicillin resistance was particularly abundant, especially during the CSO event, so these isolates were studied further using disk susceptibility tests to assess multidrug resistance. During a CSO overflow event, 82% of these isolates were resistant to five or more antibiotics, and 44% were resistant to seven or more. The latter statistic contrasts starkly with the upstream reference site, where only 4% of isolates displayed resistance to more than seven antibiotics. DNA sequencing (16S rRNA gene) revealed that ~35% of our isolates were opportunistic pathogens, comprised primarily of the genera Stenotrophomonas, Pseudomonas, and Chryseobacterium. Together, these results demonstrate that CSOs can be a significant source of viable clinically-relevant bacteria to the natural environment and that multidrug resistance is an important understudied component of the environmental spread of antibiotic resistance.

β-Lactam antibiotics and antibiotic resistance in Asian lakes and rivers: An overview of contamination, sources and detection methods

Lakes and rivers are sources of livelihood, food and water in many parts of the world. Lakes provide natural resources and valuable ecosystem services. These aquatic ecosystems are also vulnerable to known and new environmental pollutants. Emerging water contaminants are now being studied including antibiotics because of the global phenomenon on antibiotic resistance. β-Lactam antibiotics are widely used in human and animal disease prevention or treatment. The emergence of antibiotic resistance is a public health threat when bacteria become more resistant and infections consequently increase requiring treatment using last resort drugs that are more expensive. This review summarizes the key findings on the occurrence, contamination sources, and determination of β-lactam antibiotics and β-lactam antibiotic resistant bacteria and genes in the Asian lake and river waters. The current methods in the analytical measurements of β-lactam antibiotics in water involving solid-phase extraction and liquid chromatography-mass spectrometry are discussed. Also described is the determination of antibiotic resistance genes which is primarily based on a polymerase chain reaction method. To date, β-lactam antibiotics in the Asian aquatic environments are reported in the ng/L concentrations. Studies on β-lactam resistant bacteria and resistance genes were mostly conducted in China. The occurrence of these emerging contaminants is largely uncharted because many aquatic systems in the Asian region remain to be studied. Comprehensive investigations encompassing the environmental behavior of β-lactam antibiotics, emergence of resistant bacteria, transfer of resistance genes to non-resistant bacteria, multiple antibiotic resistance, and effects on aquatic biota are needed particularly in rivers and lakes that are eventual sinks of these water contaminants.

Occurrence, seasonal variations, and ecological risk of pharmaceuticals and personal care products in River Ganges at two holy cities of India

Occurrence of 15 different pharmaceuticals and personal care products (PPCPs) (ibuprofen, diclofenac, ketoprofen, acetaminophen, ciprofloxacin, erythromycin, amoxicillin, ofloxacin, tetracycline, metoprolol, triclosan, salicylic acid, N, N diethyl-meta-toluamide, caffeine and β-Estradiol) belongs to eight different classes in an urban stretch of River Ganges were detected for three seasons in two holy cities Rishikesh and Haridwar (India). The overall concentration of PPCPs in the River Ganges ranged between Below Detectable Limit (BDL) to 1104.84 ng/L, with higher concentrations at anthropogenically influenced lower reaches of the River Ganges at Haridwar. Acetaminophen, triclosan, N, N diethyl-meta-toluamide (DEET), tetracycline, and caffeine showed the highest detection frequency (>90-100%) in the river. PPCPs concentration, especially for NSAIDs (Ibuprofen, ketoprofen and acetaminophen), antibiotics (ciprofloxacin, tetracycline and ofloxacin) and metabolite (salicylic acid) was found to be higher in winter compared to summer in the Ganges, possibly due to the lower biodegradation efficiency related to lesser temperatures and inadequate sunlight. While metoprolol (beta-blockers), triclosan (antibacterial), DEET (insect repellent) and caffeine (human indicator) showed a higher load in summer, possibly due to their intense uses during this period. Results of risk quiescent (RQ) revealed higher ecological risk for algae while the moderate risk for river fish biota.

The combined exposure of microplastics and toxic contaminants in the floodplains of north India: A review

Microplastics in aquatic ecosystem are an emerging environmental threat, primarily aggregating into sediments and living biota besides providing active transportation to toxic pollutants. Recent studies have revealed that a microplastic surface cannot be considered as "inert" and therefore the rate and stage of degradation of microplastic will determine its capability in adsorbing and transporting the solute to longer distances. Our concern is driven by the fact that there has been an absence of widescale research in India despite a country with one of the longest networks of rivers and a 7500 km long active coastline. Anthropogenic pollutants are expected to increase and the situation will further worsen when more persistent organic pollutants (POCs) and geogenic contaminants will find its sink via monsoon runoff. Studies on aquatic species including COD, daphnia magna and zebrafish suggest strong links of bio-accumulation, suspecting to a more serious situation for the coastal India where there is an almost three times increase in the density of the microplastics as the monsoon progresses. Evidences also suggests that microplastics can adsorb known carcinogens as well as endocrine disrupting chemicals leaving our aquatic life exposed to higher mortality. Our review is a first ever scientific attempt in compiling these evidences through researches done in this field to understand the risk that the major floodplains of North India are currently facing. We have adapted the theories and inferences of the available research to predict and postulate a probable mechanism that could explain the severity of the situation in India.