Examining plasma-generated ozone and nitric oxide's role in synthetic textile dye water remediation and ecotoxicological analysis.

Synthetic dyes produced by the textile dyeing industry and released into wastewater contribute significantly to water pollution. This study explores the efficacy and versatility of a novel multi-electrode dielectric barrier discharge (MEDBD) plasma system that mainly generates ozone (O3 generator) and nitric oxide (NO generator) selectively to degrade various synthetic textile dyes, namely Methylene Blue (MB), Congo Red (CR), Methyl Orange (MO), Crystal Violet (CV), and Evans Blue (EB). Plasma achieved selective enrichment of O3 and NO by utilizing optimized plasma generation duty cycles of 15% and 100%, respectively. The proposed O3 generator plasma involves plasma-generated aqua electron impact, excited species, and reactive oxygen species notably O3, which degrades synthetic textile dyes into simple forms such as CO2, H2O, and N2. This approach achieved over 95% degradation of the above synthetic textile dyes when employing the O3 enriched plasma with 2.44 ± 0.21 W of power. Ecotoxicological evaluation, including microbial, human cell, and phytotoxicity evaluations of the O3 generator plasma for MB and CR dye-contaminated water, underscored the potential of this plasma system for environmentally friendly dye degradation. Overall, this study promotes MEDBD plasma, particularly the O3 generator, as a sustainable and efficient solution for treating synthetic dye-contaminated water across industries.

Distribution and Fate of Polyethylene Microplastics Released by a Portable Toilet Manufacturer into a Freshwater Wetland and Lake.

A portable toilet manufacturer in northwest Indiana (USA) released polyethylene microplastic (MP) pollution into a protected wetland for at least three years. To assess the loads, movement, and fate of the MPs in the wetland from this point source, water and sediment samples were collected in the fall and spring of 2021-2023. Additional samples, including sediment cores and atmospheric particulates, were collected during the summer of 2023 from select areas of the wetland. The MPs were isolated from the field samples using density separation, filtration, and chemical oxidation. Infrared and Raman spectroscopy analyses identified the MPs as polyethylene, which were quantified visually using a stereomicroscope. The numbers of MPs in 100 mL of the marsh water closest to the source ranged from several hundred to over 400,000, while the open water samples contained few microplastics. Marsh surface sediments were highly contaminated with MPs, up to 18,800 per 30.0 g dry mass (dm), compared to core samples in the lower depths (>15 cm) that contained only smaller MPs (<200 µm), numbering 0-480 per 30.0 g (dm). The wide variations in loads of MP contaminants indicate the influence of numerous factors, such as proximity to the point source pollution, weather conditions, natural matter, and pollution sinks, namely sediment deposition. As proof of concept, we demonstrated a novel remediation method using these real-world samples to effectively agglomerate and remove MPs from contaminated waters.

Assessing farmers' knowledge of environmental policy along the Ayeyarwady River: Strides towards the Indian Ocean marine life safety.

The Ayeyarwady River Basin in Myanmar is grappling with severe environmental challenges, including soil erosion and water pollution, primarily driven by unsustainable agricultural practices. This study aims to evaluate farmers' awareness of environmental policies and identify barriers to their effective implementation. In-depth interviews were conducted with 45 stakeholders, encompassing farmers, government officials, and researchers. The findings highlight a significant lack of policy awareness among farmers, exacerbated by socio-cultural, economic, and institutional obstacles. These barriers impede the successful application of environmental policies, perpetuating environmental degradation. The study advocates for integrative strategies that encompass education, community engagement, and adaptive policy frameworks to address these complex issues. Detailed policy implications are provided, offering insights into potential solutions for enhancing the region's environmental governance and sustainable development. This research contributes to understanding the critical interplay between policy awareness and ecological management, underscoring the importance of targeted interventions to mitigate environmental threats.

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.

Evolutionary game analysis and efficiency test of water pollution control driven by emission trading: Evidence from Zhejiang Province, China.

Presently, China is actively endorsing the pilot initiative for the remunerative use and trading of emission. By examining the operation and efficacy of emission trading in the context of water pollution control, one can contribute to the advancement and refinement of this system, thereby facilitating the attainment of regional pollution reduction, carbon reduction, and high-quality development objectives. In pursuit of this objective, we develop a theoretical framework for the local government and sewage enterprises evolutionary game of water pollution control, which includes two scenarios without considering and considering emission trading for studying the influencing factors and evolution trajectory of the game subject's. Through the stability analysis, the game interactive mechanism, the difference in evolutionary trajectory, and the response logic of the decision-making body in different situations become clearly visible. Further, the system sensitivity factors are analyzed by solving the partial derivation of the area formula of the phase diagram. And the efficacy of the sewage trading system in water pollution control in Zhejiang Province is empirically examined at the micro level by adopting the trading data of the first pilot area of sewage trading in the country and the case of pollution control in Jinhua City. The research reveals the following conclusions: Under specific circumstances, emission trading can incentivize businesses and even industries to enhance pollution control measures as a whole. The performance and degree of sensitivity factors vary across gaming systems, with public reputation evaluation and central government inspection serving as positive constraints. The initial cost of paid use of emission permits, as a fixed cost component for firms to address pollution, has no effect on the enterprises' behavioral actions to satisfy emission regulations. The findings can furnish local governments with a theoretical foundation and decision support in order to optimize regulatory strategies and enhance pollution control policies.

Assessment of water quality and identification of priority areas for intervention in Guanabara Bay basin, Rio de Janeiro, Brazil, using nonparametric and multivariate statistical methods.

The Guanabara Bay hydrographic region (GBHR) has served as a central hub for human settlement and resource utilization throughout Brazil's history. However, the region's high population density and intense industrial activity have come at a cost, leading to a significant decline in water quality. This work aimed to identify homogeneous regions in GBHR according to water quality parameters in dry and rainy periods. The following water quality monitoring variables were monitored at 49 gauge stations: total phosphorus (TP), nitrate (NO3-), dissolved oxygen (DO), hydrogenionic potential (pH), turbidity (Turb), thermotolerant coliforms (TCol), total dissolved solids (TDS), biochemical oxygen demand (BOD), water temperature (Tw), and air temperature (Ta). The statistical analysis consisted of determining principal components, cluster analysis, seasonal differences, and Spearman's correlation. The water quality parameter correlations were not expressively influenced by seasonality, but there are differences in the concentrations of these parameters in the dry and rainy periods. In the dry period, urban pressure on water quality is mainly due to fecal coliforms. The resulting clusters delimited areas under urban, agricultural, and forestry influence. Clusters located in areas with high demographic density showed high concentrations of TCol and TP, while clusters influenced by forestry and agriculture had better water quality. In the rainy season, clusters with urban influence showed problems with TCol and TP, in addition to some characteristics in each group, such as high TDS, NO3-, and BOD. Forested areas showed high DO, and clusters under agricultural influence had higher concentrations of TCol, BOD, and NO3- concerning forested regions. The troubling state of sanitation in GBHR occurs in metropolitan regions due to lack of a formal sanitation system.

Bimetallic PdCu anchored to 3D flower-like carbon material for portable and efficient detection of glyphosate.

Glyphosate (Gly), as a widely used broad-spectrum herbicide, may lead to soil and water pollution due to its persistence in the environment. Herein, the co-reduction method was employed to anchor bimetallic PdCu onto the Ni and nitrogen-doped 3D Flower-like Carbon Materials (Ni@NC), creating a composite material (PdCu/Ni@NC) with high specific surface area and good catalytic performance. This composite was used to modify screen-printed electrodes (SPE) to develop a portable and efficient Gly detection platform. In the presence of Cl⁻, the copper active sites convert to CuCl, achieving signal amplification. Upon the addition of Gly, a competitive reaction between Cu and Gly converts CuCl into a Cu-Gly complex, resulting in a sharp decrease in the electrochemical signal. This signal drop is used to detect Gly. The bimetallic PdCu nanoparticles (NPs) endowed the sensing platform with better stability and electrochemical performance due to their synergistic effect, and their stability was simply verified by Density functional theory (DFT). The sensor demonstrates a linear detection range spanning from 1 × 10⁻¹ ³ to 1 × 10⁻5 M, with a limit of detection (LOD) of 3.72 × 10⁻¹ 4 M. The sensor demonstrated a recovery rate of 95.9 % to 104.5 % in actual samples such as water and soil, indicating its potential for practical application.

The Bioaccumulation of Heavy Metals in the Water and Tissues of Invasive Fish Carassius gibelio (Bloch, 1782) and Non-carcinogenic Health Risk Assessment from Meriç Delta Wetland, Türkiye.

Meriç Delta, which has a wide variety of ecosystems, is an A Class Wetland and the most significant natural stagnant freshwater ecosystem located in the south-western of Thrace Region of Türkiye. In this research, heavy metals (Cr, Ni, As, Cd, and Pb) were investigated in the surface water and Carassius gibelio (Bloch, 1782) obtained from Meriç Delta lakes (Gala, Pamuklu, Sigirci, and Dalyan), which are located on an important migration route of water birds. The heavy metals in surface water samples and fish tissues were determined by ICP-MS. Dissolved oxygen, oxygen saturation (%), pH, electrical conductivity, total dissolved solids, nitrite nitrogen, nitrate nitrogen, and total phosphorus parameters were measured in surface waters. High total phosphorus content was detected in the investigated region. The measured As, Cr, and Ni values in water samples were determined to be higher than Türkiye Regulation Standards criteria. Fish were taken from Gala and Sigirci Lake. The mean concentrations of measured heavy metals were found to be below permissible values in fish muscle and gill. The target hazard quotient (THQ) and total THQ values (HI) of all heavy metals did not exceed the limit value.

Emergency of per- and polyfluoroalkyl substances in drinking water: Status, regulation, and mitigation strategies in developing countries.

The detection of per- and polyfluoroalkyl substances (PFAS) in water presents a significant challenge for developing countries, requiring urgent attention. This review focuses on understanding the emergence of PFAS in drinking water, health concerns, and removal strategies for PFAS in water systems in developing countries. This review indicates the need for more studies to be conducted in many developing nations due to limited information on the environmental status and fate of PFAS. The health consequences of PFAS in water are enormous and cannot be overemphasized. Efforts are ongoing to legislate a national standard for PFAS in drinking water. Currently, there are few known mitigation efforts from African countries, in contrast to several developing nations in Asia. Therefore, there is an urgent need to develop economically viable techniques that could be integrated into large-scale operations to remove PFAS from water systems in the region. However, despite the success achieved with removing long-chain PFAS from water, more studies are required on strategies for eliminating short-chain moieties in water.

Assessment of contaminants of emerging concern and antibiotic resistance genes in the Mapocho River (Chile): A comprehensive study on water quality and municipal wastewater impact.

The primary objective of this study was to evaluate the persistence and elimination of Contaminants of Emerging Concern (CECs) in municipal wastewater treatment plants (MWWTPs) and their presence in the Mapocho River within the metropolitan area of Santiago, Chile. The use of advanced analytical techniques, based on liquid chromatography coupled to both low and high-resolution mass spectrometry, allowed a comprehensive overview on the presence of CECs in samples. Additionally, a preliminary assessment of the microbiological aspects aimed to determine the presence of indicator microorganisms of fecal contamination, such as Escherichia coli and total coliforms was conducted. Furthermore, a qualitative assessment of Antibiotic Resistant Genes (ARGs) was performed. No CECs were detected upstream to the MWWTPs. However, the results from various wastewater samples (influent, secondary, and tertiary effluents) revealed significant diversity, with 73 CECs detected alongside prevalent ARGs including sulI, sulfII, qnrB, and blaTEM. The presence of CECs and ARGs downstream of the MWWTP in the Mapocho River was mainly attributed to effluent discharge. On the other hand, typical values for a healthy river and a MWWTP with a final disinfection stage were found in terms of fecal contamination. Consequently, the imperative for developing tertiary or quaternary treatments capable of degrading CECs and ARGs to minimize environmental impact is underscored. These findings hold public health significance, offering insights into potential risks and influencing future legislative measures in Chile.

Variability of Bile Baseline Excitation-emission Fluorescence of Two Tropical Freshwater Fish Species.

The quantification of pollutant metabolites in fish bile is an efficient approach to xenobiotic pollution monitoring in freshwaters since these measurements directly address exposure. Fluorescence excitation-emission matrix spectroscopy (EEMS) has demonstrated to be a highly specific and cost-effective technique for polycyclic aromatic hydrocarbon (PAH) and PAH-metabolite identification and quantification. EEMS ability to quantify these compounds strongly depends on the intensity and variability of the bile baseline fluorescence (BBF). We found large differences in BBF among Aequidens metae (AME) individuals and of these with Piaractus orinoquensis (PIO). Moreover, BBF was large enough that solvent dilutions of over 1:400 were needed to avoid inner filter effects. We used parallel factor analysis (PARAFAC) to model the intra- and inter-species BBF variability. PARAFAC successfully decomposed the EEMS set into three fluorophores present in all samples, although in concentrations spreading over ~ 3 orders of magnitude. One of the factors was identified as tryptophan. Tryptophan and Factor 2 were covariant and much more abundant in AME than in PIO, while Factor 3 was ~ 6 times more abundant in PIO than in AME. Also, tryptophan was ~ 10x more abundant in AME specimens immediately caught in rivers than in their laboratory-adapted peers. The PARAFAC decomposition effectiveness was confirmed by the positive proportionality of scores to dilution ratios. A large inner filter indicates that Factor 2 is as strong a light absorber as tryptophan. Our results stress the need to include bile matrix variable components for the detection and quantification of pollutant metabolites using PARAFAC.

Efficient removal of antibiotic resistance genes and of enteric bacteria from reclaimed wastewater by enhanced Soil Aquifer Treatments.

Soil Aquifer Treatment (SAT) is a robust technology to increase groundwater recharge and to improve reclaimed water quality. SAT reduces dissolved organic carbon, contaminants of emerging concern, nutrients, and colloidal matter, including pathogen indicators, but little is known about its ability to reduce loads of antibiotic resistance genes (ARGs) from reclaimed waters. Here we test six pilot SAT systems to eliminate various biological hazards from the secondary effluents of a wastewater treatment plant (WWTP), equipped with reactive barriers (RBs) including different sorptive materials. Using flow cytometry, qPCR and 16S rRNA gene amplicon sequencing methods, we determined that all six SAT systems reduced total loads of bacteria by 80 to 95 % and of clinically relevant ARGs by 85 to 99.9 %. These efficiencies are similar to those reported for UV/oxidation or membrane-based tertiary treatments, which require much more energy and resources. The presence and composition of reactive barriers, the season of sampling (June 2020, October 2020, and September 2021), or the flow regime (continuous versus pulsating) did not affect ARG removal efficiency, although they did alter the microbial community composition. This suggests that an adequate design of the SAT reactive barriers may significantly increase their performance. Under a mechanistic point of view, we observed an ecological succession of bacterial groups, linked to the changing physical-chemical conditions along the SAT, and likely correlated to the removal of ARGs. We concluded that SAT is as cost-efficient technology able to dramatically reduce ARG loads and other biological hazards from WWTP secondary effluents.

Singlet oxygen dominant-activation by hollow structural cobalt-based MOF/peroxymonosulfate system for micropollutant removal.

Despite the keen interest in potentially using the metal-organic framework (MOF) in advanced oxidation processes (AOPs), their application for environmental abatement and the corresponding degradation mechanisms have remained largely elusive. This study explores the use of cobalt-based MOF (CoMOF) for peroxymonosulfate (PMS) activation to remove tetracycline (TC) from water resources. Under optimal conditions, the given catalytic system could achieve a TC removal of 83.3%. Radical quenching tests and EPR analysis revealed that SO4•-, HO•, •O2-, and 1O2 could participate in the catalytic degradation, but the discernible removal mechanism was mainly ascribed to the nonradical pathway induced by 1O2. At only 5 mg/L of CoMOF, the performance of the catalytic system was superior to that of PMS alone for different types of micropollutants. The CoMOF/PMS system could also reliably deal with typical anions in water, such as Cl-, SO42-, HCO3-, and PO43-. The MOF catalyst could last for four cycles with a minor decrease in reactivity of ∼30%. However, the removal performance decreased markedly when aromatic natural organic matter (NOM) were present in the water bodies, and the effectiveness was lower in alkaline or acidic environments. Our work offers insights into the catalytic degradation of CoMOF/PMS applied in contaminated water remediation and serves as a baseline for fabricating an efficient MOF with enhanced catalytic performance and stability.

Influence of Pd, Pt and Au nanoparticles in the photocatalytic performance of N-TiO2 support under visible light.

In this article, we report the modification and photocatalytic evaluation of commercial TiO2-P25 under visible light for methyl orange (MO) dye degradation under visible light. The activity of materials doped with N, Pd, Pt and Au on to the TiO2-P25 was evaluated, with optimal photocatalytic performance achieved using Au nanoparticles doped on an N-functionalized titania surface. X-ray diffraction (XRD), physical nitrogen adsorption/desorption isotherm curves, transmission electron microscopy (TEM), diffuse reflectance spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) were used to study the structural and textural properties of the samples. The chemical species present in the bulk and surface of the catalysts were identified using X-ray photoelectron spectroscopy (XPS) and microwave plasma-atomic emission spectroscopy. The results show that Au/N-TiO2 photocatalyst presents a remarkable enhanced activity for MO dye degradation, under visible light illumination, reaching 100% after 4 h. The enhanced photocatalytic activity using this composite is attributable to the well-dispersed and small size of Au nanoparticles, large surface area, reduction of band-gap energy and the interaction between nitrogen and Au which promoted a synergistic effect. This article is part of the discussion meeting issue 'Green carbon for the chemical industry of the future'.

Assessment and monitoring of leather effluent discharge from Dewas and Ranipet and their computational approach.

The swift pace of industrialization, urbanization, and burgeoning populations propel the surge in demand for manufactured goods and infrastructure. The wastewater produced during leather processing comprises a cocktail of organic and inorganic chemical contaminants that have the potential to affect the environment. This study focuses on conducting a comparative physico-chemical, analytical, in vitro, and in silico toxicity assessment and monitoring of leather effluent discharged from two different areas, namely, Dewas and Ranipet. The physicochemical analysis of collected effluents revealed higher levels of biochemical oxygen demand, chemical oxygen demand, total dissolved solids, total suspended solids, and heavy metals than the permissible limit fixed by the Central Pollution Control Board (CPCB). The X-ray powder diffraction analysis of both samples identified the existence of crystalline and amorphous phases. The functional composition of compounds was identified through the analysis of Fourier-Transform Infrared Spectroscopy, which revealed the existence of C-H, O-H, N-H, C = O, C=C, and C≡C stretching vibrations. A variety of compound derivatives, including amines, organic acids, organometallic compounds, alcohols, hydrocarbons, esters, aldehydes, ketones, aromatic, and organogermanium, were identified by Gas Chromatography-Mass Spectrometry. An assessment and monitoring of the phytotoxicity of effluent on the germination of Vigna radiata seeds reveals that (100%) of both Dewas and Ranipet leather effluents inhibited seed germination by 33.34% and 100%. The incorporation of Absorption-Distribution-Metabolism-Excretion-Toxicity (ADMET) analysis improved comprehension of the toxicity profiles of the GC-MS-identified compounds. Moreover, the result of docking studies revealed that cytochrome P450 showed the highest binding affinity towards 1,3-benzodioxol-2-one, hexahydro-cis with an affinity score of - 7.1 kcal/mol. The overall research revealed that the leather effluents from Dewas and Ranipet exhibit significant toxicity, highlighting the necessity of better wastewater management. In the future, innovative treatment methods and environmental friendly processes can be developed to minimize the detrimental effects of leather effluents.

Per- and polyfluoroalkyl substances contamination of drinking water sources in Africa: Pollution sources and possible treatment methods.

Despite the detection of poly- and perfluorinated alkyl substances (PFAS) in the water system in Africa, the effort towards mitigating PFAS in water in Africa needs to be better understood. Therefore, this review evaluated the contamination status and mitigation methods for handling PFAS-contaminated water systems in Africa. The findings revealed the presence of PFAS in wastewater treatment plant (WWTP) effluents, surface water and commercially available bottled and tap water in African countries. The concentration of PFAS in drinking water sources reviewed ranged from < limits of quantification to 778 ng L-1. The sources of PFAS in water systems in Africa are linked to uncontrolled importation of PFAS-containing products, WWTP effluents and inappropriate disposal of PFAS-containing materials. The information on treatment methods for PFAS-contaminated water systems is scanty. Unfortunately, the treatment method is challenged by poor water research infrastructure and facilities, lack of awareness, poor research funding and weak legislation; however, adsorption and membrane technology seem favourable for removing PFAS from water systems in Africa. It is essential to focus on monitoring and assessing drinking water quality in Africa to reduce the disease burden that this may cause. Most African countries' currently implemented water treatment facilities cannot efficiently remove PFAS during treatment. Therefore, governments in Africa need to fund more research to develop an efficient water treatment technique that is sustainable in Africa.

Plastic litter is a part of the carbon cycle in an urban river: Microplastic and macroplastic accumulate with organic matter in floating debris rafts.

Watershed models of plastic export from rivers to oceans have large uncertainties, and improvements require direct measurements of riverine macroplastic (>5 mm) and microplastic (<5 mm). Also, plastic represents allochthonous carbon inputs to rivers but is rarely measured as carbon mass. We quantified plastic and organic matter within floating debris rafts and open water in an urban river. Macroplastics only occurred in debris rafts. Microplastics had higher concentrations in debris rafts relative to open water. Across sites, organic matter was positively correlated with microplastics and macroplastics. Last, carbon in plastic was 40% of the carbon mass in coarse particulate organic matter in debris rafts. Floating plastic litter accumulates with particulate organic matter in debris rafts. Plastic is an overlooked and ecological meaningful component of carbon standing stocks in urban rivers. Results will inform improved carbon budget calculation in rivers and watershed models of plastic export. PRACTITIONER POINTS: Plastic particles floating on the surface of an urban river accumulate in debris rafts compared to open water in terms of count and mass. Abundance and composition of plastic particles in debris rafts were distinct from those in open water areas. Plastic litter as units of carbon mass was in the same order of magnitude as carbon mass in course particulate organic matter. Plastic litter moves in similar ways to naturally occurring organic particles and should be measured as a part of the riverine carbon cycle.

Bending the curve of global freshwater biodiversity loss: what are the prospects?

Freshwater biodiversity conservation has received substantial attention in the scientific literature and is finally being recognized in policy frameworks such as the Global Biodiversity Framework and its associated targets for 2030. This is important progress. Nonetheless, freshwater species continue to be confronted with high levels of imperilment and widespread ecosystem degradation. An Emergency Recovery Plan (ERP) proposed in 2020 comprises six measures intended to "bend the curve" of freshwater biodiversity loss, if they are widely adopted and adequately supported. We review evidence suggesting that the combined intensity of persistent and emerging threats to freshwater biodiversity has become so serious that current and projected efforts to preserve, protect and restore inland-water ecosystems may be insufficient to avert substantial biodiversity losses in the coming decades. In particular, climate change, with its complex and harmful impacts, will frustrate attempts to prevent biodiversity losses from freshwater ecosystems already affected by multiple threats. Interactions among these threats will limit recovery of populations and exacerbate declines resulting in local or even global extinctions, especially among low-viability populations in degraded or fragmented ecosystems. In addition to impediments represented by climate change, we identify several other areas where the absolute scarcity of fresh water, inadequate scientific information or predictive capacity, and a widespread failure to mitigate anthropogenic stressors, are liable to set limits on the recovery of freshwater biodiversity. Implementation of the ERP rapidly and at scale through many widely dispersed local actions focused on regions of high freshwater biodiversity and intense threat, together with an intensification of ex-situ conservation efforts, will be necessary to preserve native freshwater biodiversity during an increasingly uncertain climatic future in which poorly understood, emergent and interacting threats have become more influential. But implementation of the ERP must be accompanied by measures that will improve water, energy and food security for humans - without further compromising the condition of freshwater ecosystems. Unfortunately, the inadequate political implementation of policies to arrest widely recognized environmental challenges such as climate change do not inspire confidence about the possible success of the ERP. In many parts of the world, the Anthropocene future seems certain to include extended periods with an absolute scarcity of uncontaminated surface runoff that will inevitably be appropriated by humans. Unless there is a step-change in societal awareness of - and commitment to - the conservation of freshwater biodiversity, together with necessary actions to arrest climate change, implementation of established methods for protecting freshwater biodiversity may not bend the curve enough to prevent continued ecosystem degradation and species loss.

Evaluating the spatiotemporal variation of Ba River water quality in the agricultural and urban watershed in the highland of Vietnam.

The Ba River in Vietnam has been facing pollution due to waste generation from agricultural and urban areas. This study focuses on evaluating the spatiotemporal variations in river water quality based on physicochemical characteristics and pesticide parameters for different seasons in 2022-2023. The results indicate that the concentrations of most parameters in the rainy season were higher than those in the early-dry and dry seasons due to the non-point sources in agricultural areas. Notably, the analysis of pesticide residue in both the rainy and dry seasons revealed low levels of chlorpyrifos (ethyl), and deltamethrin was detected in the only rainy season. The results from the hierarchical cluster analysis and water quality index show that the water quality at Ben Mong, An Khe, and Ba River Bridges was classified as moderately to highly polluted. These areas should focus on regular water quality monitoring and appropriate pollution source management. PRACTITIONER POINTS: Agriculture activities strongly affected the water quality of the Highland Ba River of Vietnam. Chlorpyrifos and deltamethrin pesticides (0.0074-0.0218 µg/L) were detected in Ba River. Non-point pollution sources significantly influenced water quality in the Ba River. Variations in river water quality mainly depend on seasons and locations. Water quality index values in rainy seasons (26-88) are lower than that in dry season (37-92).

Temporal distribution and ecological risk assessment for pesticides in water from the north-central coastal zone of Sinaloa, Mexico.

Water contamination with pesticides is one of the major pollution problems in northwestern Mexico, and this is due to the extensive use of pesticides in agriculture. In this research, water samples of ten sampling sites (fishing grounds, beaches, and both) were analyzed in the search for 28 pesticides (organochlorines, organophosphates, pyrethroids, carbamates, among other chemical classes), supplemented with a calculation of the resulting potential environmental risk. Pesticides were separated from the matrix by liquid-liquid extraction and quantified by gas chromatography coupled to electron micro-capture (organohalogenated) and pulsed flame photometric detectors (organophosphates). In addition, the ecotoxicological risk of pesticides in algae, invertebrates, and fish was assessed, based on seawater pesticide concentrations using the Risk Quotient (RQ) and Toxic Units (TU) approach. The results showed 18 pesticides identified in the analyzed samples, where cypermethrin and chlorpyrifos were identified with the maximum concentrations of 1.223 and 0.994 µg L-1, respectively. In addition, these two pesticides have been associated with acute toxic effects on algae, invertebrates, and fish. It is important to pay particular attention to the search for long-term alternatives to the use of chlorpyrifos and cypermethrin due to their high detection rates and the risks associated with their toxic properties. However, the adoption of alternative measures to synthetic pesticide control should be a priority, moving towards sustainable practices such as the use of biopesticides, crop rotation and polycultures.