Water Pollution Mitigation Research Articles

Green synthesis of ZnO nanocubes from Ceropegia omissa H. Huber extract for photocatalytic degradation of bisphenol An under visible light to mitigate water pollution

Plastic pollution has become a major environmental problem because it does not break down and poses risks to ecosystems and human health. This study focuses on the environmentally friendly synthesis of ZnO nanocubes using an extract from Ceropegia omissa H. Huber plant leaves. The primary goal is to investigate the viability of these nanocubes as visible-light photocatalysts for the degradation of bisphenol A (BPA). The synthesized ZnO nanocubes have a highly crystalline structure and a bandgap of 3.1 eV, making them suitable for effective visible-light photocatalysis. FTIR analysis, which demonstrates that the pertinent functional groups are present, demonstrates the chemical bonding and reducing processes that take place in the plant extract. The XPS method also studies zinc metals, oxygen valencies, and binding energies. Under visible light irradiation, ZnO nanocubes degrade BPA by 86% in 30 min. This plant-extract-based green synthesis method provides a long-term replacement for traditional procedures, and visible light photocatalysis has advantages over ultraviolet light. The study's results show that ZnO nanocubes may be good for the environment and can work well as visible light photocatalysts to break down organic pollutants. This adds to what is known about using nanoparticles to clean up the environment. As a result, this study highlights the potential of using environmentally friendly ZnO nanocubes as a long-lasting and efficient method of reducing organic pollutant contamination in aquatic environments.

A novel preparation of trace iron-doped 3D urchin-like TiO2 for efficient degradation and mineralization of trimethoprim under simulated sunlight

In this study, trace iron-doped 3D urchin-like titanium dioxide (Fe–TiO2) were prepared via a straightforward water bath process. The successful incorporation of trace iron into the TiO2 structure was confirmed through detailed EDX, EPR, and XPS analyses. Moreover, the Fe–TiO2 photocatalyst exhibited remarkable efficacy in degrading the targeted compound, trimethoprim (TMP), achieving an impressive degradation rate of 95.6 % within a concise 60-min timeframe and a captivating mineralization rate of 32.1 % within 120 min. These performance metrics outshone those of pristine TiO2 by substantial factors of 1.9 and 1.2, respectively. Photoelectric characterization results also confirmed that Fe doping significantly enhanced the efficiency of charge carrier separation of TiO2. Furthermore, the catalytic performance of Fe–TiO2 remains essentially unchanged after a tenfold expansion in equal proportion using the water bath doping system. This confirms the practicality of the batch preparation approach for Fe-doped TiO2. The Fe–TiO2 catalyst consistently demonstrated efficient degradation capabilities across various water sources, ranging from natural river water to treated secondary effluents from sewage plants and tap water, further emphasizing its significant potential for practical applications. This comprehensive study provides fresh insights into the batch preparation of doped catalysts and their utility in mitigating water pollution.

Advancing Water Sustainability: Innovative Technologies in Hydrology and Water Resources Engineering

In the evolving field of water environment, hydrology, and water resources engineering, advanced water treatment techniques have emerged as pivotal elements in addressing contemporary challenges and ensuring sustainable water management. This academic article delves into a thorough examination of these advanced techniques, offering a comprehensive review that bridges the gap between cutting-edge technology and practical applications. It systematically explores a variety of key methods, including membrane technologies, advanced oxidation processes, and biological treatment systems, highlighting their effectiveness in various scenarios. The article further assesses the implications of these technologies on sustainable water management, focusing on their environmental impact and contributions to hydrological balance. It discusses how these methods aid in mitigating water pollution, enhancing water quality, and ensuring the efficient use of water resources. Additionally, the study sheds light on the integration of these technologies into current water management practices, examining their role in addressing the challenges posed by urbanization, industrialization, and climate change. Emphasizing the interdisciplinary nature of water resources engineering, the article also explores the interplay between these advanced water treatment methods and broader environmental and hydrological systems. It underscores the necessity for an integrated approach that combines technological innovation with sustainable practices, policy-making, and community involvement. By highlighting the importance of these technologies in contemporary water management strategies, the study aims to inform and inspire ongoing research, development, and implementation in this crucial field.

Theoretical framework for assessing the economic and environmental impact of water pollution: A detailed study on sustainable development of India

This research paper aims to explore the relationship between water pollution and sustainable development. Water pollution is a significant environmental challenge that threatens the sustainability of ecosystems, human health, and economic development. Sustainable development aims to meet the needs of the present generation without compromising the ability of future generations to meet their own needs. The research methodology involves a comprehensive review of relevant literature on water pollution and sustainable development, including empirical studies, theoretical frameworks, and policy documents. The research will explore the impact of water pollution on sustainable development, the drivers of water pollution, and the policy and regulatory frameworks that promote sustainable water management. The findings of this research paper will contribute to a deeper understanding of the complex relationship between water pollution and sustainable development and provide insights into effective strategies and policies that can promote sustainable water management. The research will also highlight the importance of public awareness and education in promoting sustainable practices and behaviors that can help to prevent and mitigate water pollution. This research paper will provide valuable insights into achieving sustainable water management practices that promote environmental sustainability and socio-economic development.

Eco-friendly Nanocatalysts: Unleashing Non-Precious Metal Potential for Methylene Blue Remediation

Water pollution stemming from textile dyes, particularly methylene blue (MB), represents a formidable challenge to both the environment and human well-being. In response to this pressing issue, scientists have redirected their focus toward eco-friendly nanocatalysts as a viable remediation strategy. Nanocatalysts crafted from precious metals like platinum, palladium, and gold have indisputably demonstrated their efficacy in combatting water pollution. Nonetheless, their restricted availability and substantial costs have spurred investigations into non-precious metal-based nanocatalysts. Research outcomes have revealed that non-noble metal (FeNi)-based nanocatalysts, synthesized using natural reductants, exhibit highly promising performance in degrading methylene blue. These alternatives not only deliver impressive efficiency but also incur lower production expenses compared to their noble metal counterparts. The ecological benefits inherent in these nanocatalysts offer a sustainable means of mitigating water pollution attributed to textile dyes. Through detailed synthesis experiments, precipitation-assisted method demonstrated a slightly superior yield of 69.11% with catalytic activity of 16260 μmol MB/gNiFe.

Efficient removal of methylene yellow dye by activated carbon-chitosan composite beads

Pakistan is facing severe water scarcity and grappling with significant water pollution concerns, this study endeavors to address these environmental challenges. The focus of this research is the synthesis and application of activated carbon-based composite beads for pollutant removal and water purification. To achieve this goal, biopolymer composite beads were created using chitosan (Cs) as the matrix and activated carbon as the filler, yielding two types of beads: Cs blank beads and Cs/AC beads. These beads underwent examination of surface morphology via scanning electron microscopy (SEM) and the structural composition elucidated through FTIR spectroscopy. The presence of chitosan polymer was verified at characteristic wavenumbers such as 3298 cm-1 (N-H stretching), 2905 cm-1 (C-H stretching), 1570 cm-1 (NH bending), 1377 cm-1 (C-O-C), and 1033 cm-1 (C-OH). Furthermore, the study explored the adsorption capabilities of Cs/AC beads in the context of removing methylene yellow dye, a prevalent waterborne pollutant. The adsorption efficiency was examined with careful consideration of variables such as exposure time, adsorbent dose and pH. A systematic optimization process was employed to maximize the removal efficiency. Notably, the adsorption/removal of methylene yellow dye commenced upon exposure to Cs/AC, and after 150 minutes, a steady state was reached (92% removal), indicating no further removal. Consequently, this time point was identified as the optimal contact duration for subsequent investigations. Besides, a slightly acidic pH of 7 within the solution, coupled with higher concentrations of the adsorbent, was identified as the optimal condition. This research provides valuable insights into mitigating water pollution and improving water quality in Pakistan through the development and utilization of advanced composite materials.

Design and Fabrication of Biomass Derived Black Carbon Modified g‐C3N4/FeIn2S4 Heterojunction as Highly Efficient Photocatalyst for Wastewater Treatment

AbstractThe environmental deterioration caused by dye wastewater discharge has received considerable attention in recent decades. One of the most promising approaches to addressing the aforementioned environmental issue is the development of photocatalysts with high solar energy consumption efficiency for the treatment of dye‐contaminated water. In this study, a novel low‐cost π–π biomass‐derived black carbon modified g‐C3N4 coupled FeIn2S4 composite (i.e., FeInS/BC‐CN) photocatalyst is successfully designed and fabricated that reveals significantly improved photocatalytic performance for the degradation of Eosin Yellow (EY) dye in aqueous solution. Under dark and subsequent visible light irradiation, the amount optimized composite reveals 99% removal performance for EY dye, almost three‐fold compared to that of the pristine FeInS and BC‐CN counterparts. Further, it is confirmed by means of the electron spin resonance spectrometry, quenching experiments, and density functional theory (DFT) calculations, that the hydroxyl radicals (•OH) and superoxide radicals (•O2−) are the dominant oxidation species involved in the degradation process of EY dye. In addition, a systematic photocatalytic degradation route is proposed based on the resultant degradation intermediates detectedduring liquid chromatography tandem mass spectrometry (LC‐MS/MS) analysis. This work provides an innovative idea for the development of advanced photocatalysts to mitigate water pollution.

Enhancing sustainable crop cultivation: The impact of renewable soil amendments and digestate fertilizer on crop growth and nutrient composition

Utilizing digestate as a fertilizer enhances soil nutrient content, improves fertility, and minimizes nutrient runoff, mitigating water pollution risks. This alternative approach replaces commercial fertilizers, thereby reducing their environmental impact and lowering greenhouse gas emissions associated with fertilizer production and landfilling. Herein, this study aimed to evaluate the impact of various soil amendments, including carbon fractions from waste materials (biochar, compost, and cocopeat), and food waste anaerobic digestate application methods on tomato plant growth (Solanum lycopersicum) and soil fertility. The results suggested that incorporating soil amendments (biochar, compost, and cocopeat) into the potting mix alongside digestate application significantly enhances crop yields, with increases ranging from 12.8 to 17.3% compared to treatments without digestate. Moreover, the combination of soil-biochar amendment and digestate application suggested notable improvements in nitrogen levels by 20.3% and phosphorus levels by 14%, surpassing the performance of the those without digestate. Microbial analysis revealed that the soil-biochar amendment significantly enhanced biological nitrification processes, leading to higher nitrogen levels compared to soil-compost and soil-cocopeat amendments, suggesting potential nitrogen availability enhancement within the rhizosphere's ecological system. Chlorophyll content analysis suggested a significant 6.91% increase with biochar and digestate inclusion in the soil, compared to the treatments without digestate. These findings underscore the substantial potential of crop cultivation using soil-biochar amendments in conjunction with organic fertilization through food waste anaerobic digestate, establishing a waste-to-food recycling system.

Tidal and vertical flow constructed wetland treatment for graywater modeling and reusing with biochar cadmium adsorption.

This study addresses a persistent environmental concern related to graywater discharge from households, highlighting its potential to contribute to increased pollution in water bodies. To mitigate this issue, the research explores the use of subsurface flow-built wetlands, specifically focusing on the innovative application of constructed tidal and vertical flow wetlands (CTWFWs) as wastewater treatment systems. The study not only evaluates the efficacy of these CTWFW systems but also delves into the crucial aspects of their operation and their interactions with the biological, physical, and chemical characteristics of graywater. A key innovation of this research is the investigation of zeolite's effectiveness and the utilization of perlite-based plant species in both mixed and monoculture configurations to develop lab-scale hybrid constructed wetlands (HCWs). These HCWs are designed for the removal of organic matter and nutrients from graywater, offering a sustainable and cost-effective solution to this environmental challenge. The study also examines the dynamic processes involved in graywater treatment, emphasizing how the removal of parameters like biological oxygen demand (BOD), nutrients, total suspended solids (TSS), and disinfection efficiency can significantly impact the effectiveness of treatment systems. Furthermore, the research scrutinizes the intricate relationship between the treatment unit's dimensions and the specific criteria that need to be met for efficient graywater treatment. Intriguingly, the study tracks the changes in graywater composition and the treatment process over time. By conducting on-site measurements of various physicochemical characteristics such as temperature, dissolved oxygen (DO), electrical conductivity (EC), turbidity, total dissolved solids (TDS), and pH, the research offers a comprehensive understanding of the treatment system's performance and adaptability. The study dives into the microbial communities within the treatment systems, utilizing 16S rRNA amplicon sequencing to characterize the complex microbial ecosystem present in graywater. This approach sheds light on the interplay between microorganisms, physicochemical conditions, plant responses, substrate dynamics, and the production of microbial metabolites. It underscores the holistic nature of the research, encompassing various aspects of graywater treatment. Notably, the study explores the application of biochar in combination with the target heavy metal, cadmium (Cd), within constructed wetlands (CWs). This innovative approach aims to better understand the kinetics and isothermal adsorption of lead in the context of mouthwash residue, expanding the knowledge base in this critical area. The research findings are substantial, with remarkable removal efficiencies achieved for parameters like TSS, turbidity, chemical oxygen demand (COD), nitrate, and phosphate. These results underscore the practicality and effectiveness of the proposed treatment methods. This holistic and pioneering research significantly advances the understanding of sustainable graywater treatment, offering valuable insights and practical solutions to mitigate water pollution concerns. PRACTITIONER POINTS: This study addresses a persistent environmental concern related to greywater discharge from households, highlighting its potential to contribute to increased pollution in water bodies. The study not only evaluates the efficacy of these CTWFW systems but also delves into the crucial aspects of their operation and their interactions with the biological, physical, and chemical characteristics of greywater. A key innovation of this research is the investigation of zeolite's effectiveness and the utilization of perlite-based plant species in both mixed and monoculture configurations to develop lab-scale hybrid constructed wetlands (HCWs).

Development of a coupled model to simulate and assess arsenic contamination and impact factors in the Jinsha River Basin, China

With the increasing severity of arsenic (As) pollution, quantifying the environmental behavior of pollutant based on numerical model has become an important approach to determine the potential impacts and finalize the precise control strategies. Taking the industrial-intensive Jinsha River Basin as typical area, a two-dimensional hydrodynamic water quality model coupled with Soil and Water Assessment Tool (SWAT) model was developed to accurately simulate the watershed-scale distribution and transport of As in the terrestrial and aquatic environment at high spatial and temporal resolution. The effects of hydro-climate change, hydropower station construction and non-point source emissions on As were quantified based on the coupled model. The result indicated that higher As concentration areas mainly centralized in urban districts and concentration slowly decreased from upstream to downstream. Due to the enhanced rainfall, the As concentration was significantly higher during the rainy season than the dry season. Hydro-climate change and the construction of hydropower station not only affected the dissolved As concentration, but also affected the adsorption and desorption of As in sediment. Furthermore, As concentration increased with the input of non-point source pollution, with the maximum increase about 30%, resulting that non-point sources contributed important pollutant impacts to waterways. The coupled model used in pollutant behavior analysis is general with high potential application to predict and mitigate water pollution.

Harnessing Solar Power: A Review of Photovoltaic Innovations, Solar Thermal Systems, and the Dawn of Energy Storage Solutions

The goal of this review is to offer an all-encompassing evaluation of an integrated solar energy system within the framework of solar energy utilization. This holistic assessment encompasses photovoltaic technologies, solar thermal systems, and energy storage solutions, providing a comprehensive understanding of their interplay and significance. It emphasizes the importance of solar energy as a renewable resource and its role in addressing global energy demand and mitigating climate change. The review highlights the significance of advancements in various solar energy technologies, focusing on their environmental benefits, including greenhouse gas emissions reduction and air and water pollution mitigation. It explores the evolution of photovoltaic technologies, categorizing them into first-, second-, and third-generation photovoltaic cells, and discusses the applications of solar thermal systems such as water heaters, air heaters, and concentrators. The paper examines key advancements in energy storage solutions for solar energy, including battery-based systems, pumped hydro storage, thermal storage, and emerging technologies. It references recent published literature to present findings on energy payback time, carbon footprint, and performance metrics. Challenges to widespread adoption are discussed, including cost and economic viability, intermittency, environmental impacts, and grid integration. Strategies to overcome these challenges, such as cost reduction, policy support, energy storage integration, and sustainable practices, are presented based on published literature. By bridging gaps in existing literature, this comprehensive resource aims to equip researchers, policymakers, and industry professionals with insights into forging a sustainable and renewable energy future.

A Spatially Explicit Hydro-Economic Modeling Procedure to Design Cost-Effective Agri-Environment Schemes for Mitigating Water Pollution from Cropland

Agricultural intensification is a key driver of water pollution in many parts of the world. A frequent policy response is to implement mitigation measures in the context of agri-environmental schemes (AESs). We develop a hydro-economic modeling procedure to design cost-effective AESs to mitigate water pollution from nitrogen and phosphorus from cropland. Our procedure considers spatial heterogeneity of mitigation impacts and of costs of cropland management measures. It further takes into account in the optimization that AES participation is voluntary and farmers who may participate in an AES will select between different cropland management measures. We demonstrate how the procedure works by applying it to the Baishahe watershed in Shanxi Province, China. As a result, we obtain a cost-effective AES with a set of cropland management measures and the associated payment levels that are able to achieve weighted minimized nitrogen and phosphorus loads in the watershed for different budgets. We find, for example, that a cost-effective AES for a budget of 100,000[Formula: see text]RMB consists of the two measures of implementing a filter strip of 5[Formula: see text]m and reducing chemical fertilizers by 25% for which the farmers receive payments of 134[Formula: see text]RMB and 88[Formula: see text]RMB, respectively, which induces the reduction of nitrogen by 6.9% and phosphorus by 7.8%.

Fabrication of para-dimethylamine calix[4]arene functionalized self-assembled graphene oxide composite material for effective removal of 2, 4, 6-tri-Cholorphenol from aqueous environment

Water pollution caused by the release of organic pollutants is a major environmental concern worldwide. These pollutants can have harmful effects on aquatic ecosystems and the organisms living within them, as well as on human health when contaminated water is consumed. It is essential to implement proper treatment and management strategies to prevent and mitigate water pollution. Moreover, the major untreated industrial effluents are synthetic organic compounds especially 2,4,6-trichlorophenol (TCP) which cause several environmental issues and heath related problems in humans. To cope with this problem, an excellent 2D porous material based on p-DMAC4/GO composite has been synthesized as adsorbent material for the effective removal of 2,4,6-trichlorophenol pollutant from wastewater. In this regard, the advanced analytical tools such as Fourier-Transform infrared (FT-IR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray spectroscopy (EDS) were used for its characterization. The results justified the chemical composition, excellent crystalline nature, surface morphology and elemental composition of the synthesized composite material. The synthesized adsorbent material showed 95% adsorption of TCP from wastewater system at optimal conditions i.e., pH (6), adsorbent dosage (30 mg) and shaking time (60 min). The mathematical models such as isotherms, thermodynamics and kinetics studies validate the nature of adsorption process of TCP pollutant. The adsorption data found to be best fitted with Langmuir isotherms (R2 = 0.99); whereas kinetic study suggested the pseudo-second-order nature of reaction with R2 = 0.99. The thermodynamics study confirmed the spontaneous and endothermic nature of the TCP pollutant onto the surface of p-DMAC4/GO material. Moreover, the results of current work were also compared with existing reported adsorbents and data suggested the higher efficiency, feasibility, and reusability of p-DMAC4/GO material to remove the TCP pollutant from the wastewater system.

Immobilization of Ag nanoparticles on NiFe2O4@TiO2@PDA: Multifunctional catalytic action toward the reduction of 4-Nitrophenol and photodegradation of methylene blue and ciprofloxacin

Freshwater, an essential commodity of life, is under threat by the presence of pernicious chemicals, such as 4-nitrophenol (4-NP), organic azo dyes, and colorless antibiotic pollutants, leading to water pollution. It is an absolute necessity to transform these pernicious chemicals into benign compounds to mitigate water pollution and safeguard life on Earth. One such effort in the current work is the development of a recyclable, multifunctional, and heterogeneous NiFe2O4@TiO2@PDA-Ag magnetic nanocatalyst for the reduction of 4-NP to 4-aminophenol (4-AP) and the photocatalytic degradation of methylene blue (MB) (an organic azo dye) and ciprofloxacin (CIP) (a colorless antibiotic pollutant) under irradiation with direct sunlight. Characterization of the developed catalyst was achieved using various spectroscopic and analytical methods (XRD, FTIR & UV–Vis spectroscopy, SEM, TEM, and XPS). The visible light active nature of the catalyst was confirmed by our UV–Vis spectroscopic data. The reduction of 4-NP to 4-AP with 97% conversion was achieved using the catalyst at room temperature in an aqueous medium in the presence of sodium borohydride (NaBH4) at a rate constant of 0.462 min−1. The photocatalytic degradation of MB and CIP was achieved using the catalyst under irradiation with direct sunlight, in which 96.5 and 68% degradation was observed with a degradation rate constant of 0.0483 and 0.0750 min−1 respectively. The presence of a magnetic NiFe2O4 core in the catalyst enables its recovery with the aid of the external magnet, its reusability was assessed and exhibited good efficacy up to five cycles. The magnetic nature of the catalyst was confirmed using vibrating sample magnetometry (VSM). The synthesis of a sole reusable magnetic catalyst suitable for the removal of three toxic pollutants under normal conditions adopting a facile methodology with excellent activity up to five cycles is rare and thus, the findings from the present work provide helpful information in wastewater treatment.

Synthesis of solar-driven Cu-doped graphitic carbon nitride photocatalyst for enhanced removal of caffeine in wastewater

Caffeine (CaF), a widely consumed compound, has been associated with various harmful effects on human health, including metabolic, cardiovascular disease, and reproductive disorders. Moreover, it poses a signifincant threat to organisms and aquatic ecosystems, leading to water pollution concerns. Therefore, the removal of CaF from wastewater is crucial for mitigating water pollution and minimizing its detrimental impacts on both humans and the environment. In this study, a solar-driven Cu-doped graphitic carbon nitride (Cu/CN) photocatalyst was synthesized and evaluated for its effectiveness in oxidizing CaF in wastewater. The Cu/CN photocatalyst, with a low band gap energy of 2.58eV, exhibited superior performance in degrading CaF compared to pure graphitic carbon nitride (CN). Under solar light irradiation, CuCN achieved a remarkable CaF degradation efficiency of 98.7% CaF, surpassing CN's efficiency of 74.5% by 24.2%. The synthesized Cu/CN photocatalyst demonstrated excellent removal capability, achieving a removal rate of over 88% for CaF in wastewater. Moreover, the reusability test showed that Cu/CN could be successfully reused up to five cycles maintaining a high removal efficiency of 74% for CaF in the fifth cycle. Additionally, the study elucidated the oxidation mechanism of CaF using solar-driven Cu/CN photocatalyst and highlighted the environmental implications of the process.

Payments for Watershed Services and corporate green innovation

China is promoting Payments for Watershed Services (PWS) in increasing regions for water pollution mitigation. In this study, we provided empirical evidence on the influence of China's PWS programs on green innovation based on green patent data. Results show that PWS results in more R&D and green innovation at the corporate level. We attribute this to increased regulatory pressure on firms following PWS by providing evidence that firm-level environmental penalties are increased in upstream areas following PWS, and PWS's positive effect on R&D and green innovation is stronger in firms with more sewage discharge and environmental penalties. Moreover, firms that invested in wastewater treatment facilities may not increase as much green innovation as other firms after PWS. Furthermore, this positive effect is more pronounced among firms with more R&D staff, less financial constraints, lower market competition, and state-owned enterprises.

Copper removal and recovery from electroplating effluent with wide pH ranges through hybrid capacitive deionization using CuSe electrode

In modern industry, selective extraction and recovery of Cu from strongly acidic electroplating effluent are crucial to reduce carbon emissions, alleviate resource scarcity, and mitigate water pollution, yielding considerable economic and environmental benefits. This study proposed a high-efficiency CuSe electrode to selectively remove Cu from electroplating effluent via hybrid capacitive deionization (HCDI). The potential of this electrode was thoroughly evaluated to assess its effectiveness. The CuSe electrode exhibited superior deionization performance in terms of Cu adsorption capacity, selectivity, and applicability in various water matrices. Specifically, under strong acid conditions (1 M H+), the CuSe electrode maintained an optimal adsorption capacity of 357.36 mg g−1 toward Cu2+. In systems containing salt ions, heavy metals, and actual electroplating wastewater, the CuSe electrode achieved a remarkable removal efficiency of up to 90% for Cu2+ with a high distribution coefficient Kd. Notably, the capacitive deionization (CDI) system demonstrated the simultaneous removal of Cu-EDTA. The removal mechanism was further revealed using ex-situ X-ray diffraction and X-ray photoelectron spectroscopy analyses. Overall, this study presents a practical approach that extends the capabilities of CDI platforms for effectively removing and recovering Cu from acidic electroplating effluent.

Determining the main contributing factors to nutrient concentration in rivers in arid northwest China using partial least squares structural equation modeling

Understanding the main driving factors of oasis river nutrients in arid areas is important to identify the sources of water pollution and protect water resources. Twenty-seven sub-watersheds were selected in the lower oasis irrigated agricultural reaches of the Kaidu River watershed in arid Northwest China, divided into the site, riparian, and catchment buffer zones. Data on four sets of explanatory variables (topographic, soil, meteorological elements, and land use types) were collected. The relationships between explanatory variables and response variables (total phosphorus, TP and total nitrogen, TN) were analyzed by redundancy analysis (RDA). Partial least squares structural equation modeling (PLS-SEM) was used to quantify the relationship between explanatory as well as response variables and fit the path relationship among factors. The results showed that there were significant differences in the TP and TN concentrations at each sampling point. The catchment buffer exhibited the best explanatory power of the relationship between explanatory and response variables based on PLS-SEM. The effects of various land use types, meteorological elements (ME), soil, and topography in the catchment buffer were responsible for 54.3% of TP changes and for 68.5% of TN changes. Land use types, ME and soil were the main factors driving TP and TN changes, accounting for 95.56% and 94.84% of the total effects, respectively. The study provides a reference for river nutrients management in arid oases with irrigated agriculture and a scientific and targeted basis to mitigate water pollution and eutrophication of rivers in arid lands.

Water Pollution and Pollution–Control Capacity in Chinese Provinces: Panel Estimations of Provincial Environmental Kuznets Curves

China’s rapid industrialization and urbanization in recent decades have deteriorated its water resource quality. This study focused on water pollution in terms of the chemical oxygen demand (COD) and the levels of ammonia nitrogen in the industrial and household discharges of different Chinese provinces. Although the heterogeneity of environmental Kuznets curves (EKCs) from Chinese provinces has been studied, the positions of provincial EKCs (which reflect the province-specific pollution effects not affected by the provincial income levels) have not been investigated to date. Therefore, through a factor analysis of the heterogeneity of provincial pollution under the EKC framework, we investigated how the capacity shortage for pollution control contributes to the provincial pollution levels. We also evaluated the heterogeneity of the EKCs from the provinces in terms of their positions (not their shapes), using a fixed-effect model to extract the province-specific pollution effects. The capacity shortage for pollution control, as one of the pollution factors, accounted for (a) 30% of industrial COD and industrial ammonia nitrogen; (b) 60% of household COD; and (c) 80% of household ammonia nitrogen. Our results indicate that China still has a large capacity to mitigate water pollution via policies and by building the capacity for pollution control through the development and training of human resources.

Resolving the Ganges pollution paradox: A policy‐centric systematic review

AbstractDespite the fact that it is one of the most sacred and holy rivers in the world, the Ganges River is paradoxically among the most polluted. Over the past decade, researchers have described various mechanisms and actions for improving the pollution problem within the Ganges watershed. The aim of this policy‐centric systematic review is to summarize these recommendations to make them more accessible for concerned citizen groups and planners while also critically appraising their findings. Using the Reporting standards for Systematic Evidence Syntheses (ROSES) framework, our findings indicate that there are a wide range of potential solutions for mitigating pollution in the river system that originate from 37 peer‐reviewed sources that encompass field studies, modeling analyses, and review articles. While we find that there are many actionable and thought‐provoking recommendations for improving water quality and pollution mitigation given by authors studying the Ganges, there are also areas for improvement. Notably, there is a heavy focus on state‐centric planning in the basin with only a few examples of policies that have been tailored toward encouraging community‐based solutions. This lack of community‐based planning may relate to the fact that there is also a missing social dimension to policy recommendations in the Ganges watershed, where most of the articles that we reviewed were published in natural science journals and were not interdisciplinary in nature. Better reporting standards for recommendations arising from reviews and a greater focus on the interrelations between different components of the Ganges system may also yield novel and more trustworthy policy findings for practitioners.