Industrial Wastewater Discharge Research Articles

Combining APCS-MLR model to evaluate the distribution and sources of rare earth elements in a large catchment

Rare earth elements (REEs), functioning as indicators for environmental tracking, revealing the impacts of human activities on changes in aquatic ecosystems. However, systematic research on the geochemical characteristics of REEs in large river basins remains relatively scarce. Therefore, this research investigates the geochemical properties of REEs within the Yangtze River basin, analyzing the quantity and spatial distribution of REEs in surface aquatic environments across the upstream, midstream, and downstream segments of the Yangtze River, and quantitatively assessing their sources. Results indicate that the REE concentration in the upstream and downstream areas are significantly higher than in the midstream, with average concentrations of 0.69 μg/L, 0.56 μg/L, and 0.39 μg/L, respectively. REEs in the Yangtze River basin are enriched in light rare earth elements (LREEs), exhibiting a slight negative cerium (Ce) anomaly and a pronounced positive europium (Eu) anomaly. The Ce anomaly correlates with pH levels, and the Eu anomaly is largely attributed to the selective chemical decomposition and solubilization of feldspar minerals. Correlation analysis indicates that REE sources are related to manganese (Mn). Utilizing the Absolute Principal Component Scores-Multiple Linear Regression (APCS-MLR) model, the principal sources of REEs are further determined to be mineral sources (36.80%), industrial sources (45.61%), and mixed sources (17.59%). Further analysis suggests that mining and dissolution of Mn-bearing feldspar minerals, along with the discharge of industrial wastewater, considerably influence REE concentrations in the basin. This study reveals the anthropogenic and natural factors influencing the distribution of REEs in the Yangtze River basin, laying a foundational framework for investigating how human activities affect the dispersion of REEs in aquatic environments.

Do Fiscal Incentives Contribute to Pollution Control? Empirical Evidence from China

Given the growing concerns over environmental degradation and the demand for sustainable development, the Chinese government has implemented several fiscal incentive policies to enhance environmental governance. Taking the phased comprehensive demonstration cities of the Energy Saving and Emission Reduction Fiscal Policy (ESERFP) as an exogenous shock, this study uses a staggered difference-in-differences method to evaluate the impact of the fiscal incentive policy on pollution control using panel data from 268 prefecture-level cities in China from 2003 to 2017. The results indicate that the industrial pollutant emissions in the demonstration cities significantly decreased compared with those in the non-demonstration cities under the influence of the ESERFP. Specifically, industrial wastewater discharges in the demonstration cities decreased by 15.5% while industrial sulfur dioxide emissions decreased by 19.5%. Moreover, promoting industrial structure upgrades and green technology innovations are the main mechanisms of the ESERFP in reducing industrial pollution emissions. Furthermore, the emission-reduction effect of the ESERFP is more significant in areas with more fiscal resources, lower promotion incentives based on local economic performance, greater emphasis on environmental protection, and those with no old industrial bases. Further analysis shows that the positive effect of the ESERFP on pollution control in the demonstration cities remains relatively effective after the demonstration period ends, and the policy does not sacrifice economic dividends. Overall, this study explores the impact of fiscal incentive policies designed to achieve environmental improvements via pollution control, offering valuable fiscal policy insights for China and other developing economies seeking solutions to environmental pollution, including fiscal incentive policy formulation and implementation, fiscal incentives to support regional green transformations, improving the differentiation and precision of fiscal incentives and enhancing environmental performance assessment.

Seasonal occurrence and ecological risk assessment of polycyclic aromatic hydrocarbons in the sediments and water in the left-bank canals of Indus River, Pakistan.

This study investigated a pressing environmental concern: the presence, distribution, sources, and ecological implications of sixteen polycyclic aromatic hydrocarbons (PAHs) in the left-bank canals of Kotri barrage-Akram, Pinyari, and Phuleli of the Indus River in Pakistan. These vital waterways, crucial for industrial, domestic, and agricultural activities, are experiencing contamination threats from anthropogenic sources, particularly PAHs. The study collected three water and two sediment samples from each canal in pre-monsoon and post-monsoon seasons. Then the EPA's liquid-liquid extraction method and gas chromatography determined the concentrations of PAHs. The findings of this study reveal alarming contamination levels, with pre-monsoon concentrations ranging from 22.256 to 836.455ng/L in water and 1,459.941 to 43,179.243ng/g in sediments. The post-monsoon concentrations ranged from 60.352 to 5663.058ng/L in water and 2976.770 to 15,238.335ng/g in sediments. The diagnostic ratios and principal component analysis (PCA) identified multiple sources of contamination, including industrial and domestic wastewater discharge, solid waste burning, vehicular emissions, biomass combustion, and petroleum residues. Furthermore, the assessment of the toxic equivalency factor (TEF) underscored the heightened carcinogenic potential of certain PAHs, notably benzo(a)pyrene and benzo(a)anthracene. Thus, the high levels of PAH contamination pose severe health risks to both human populations and aquatic ecosystems, emphasizing the urgency of addressing this issue. Stricter regulations governing industrial and domestic waste discharge, advocacy for cleaner fuel technologies, and the implementation of effective waste management practices must be initiated as crucial strategies in safeguarding the environmental integrity of the left-bank canals and the health of the surrounding communities.

Determination of geochemical stability of swamp ecosystems of the taiga zone of Western Siberia to anthropogenic impact

Relevance. The need for scientifically based regulation of impacts on wetland ecosystems taking into account their specificity and geochemical stability. Aim. To determine the geochemical stability of wetlands in the taiga zone of Western Siberia to pollutants for two typical cases associated with: 1) operation of sludge pits; 2) discharge of domestic and industrial wastewater. Methods. Mathematical modeling, statistical methods. Results and conclusions. The authors have carried out the analysis of the results of studies of the chemical composition of wetland waters and extracts from peat and mineral soils of wetlands in the taiga zone of Western Siberia (mainly in the Tomsk region, as well as in the adjacent territories of the Khanty-Mansiysk Autonomous Okrug, Novosibirsk and Omsk regions). They obtained the estimates of the average values of geochemical indicators of wetland waters and peat by the depth of the peat deposit in peat bogs with varying degrees of anthropogenic impact. The paper introduces the method for assessing the anthropogenic impact of wastewater discharge and geomigration on swamps in areas where oil and gas facilities are located (permissible concentrations in wastewater entering swamp ecosystems), taking into account the «geochemical background» and sorption capacity of peat. In particular, the authors substantiated and tested the method for assessing the values of permissible concentrations, which should be considered as a «relatively safe» level of impact on swamp ecosystems, at which secondary pollution of swamp waters is not expected. It is shown that anthropogenic changes are mainly limited vertically by the upper layer of the peat deposit up to 1–2 m, and horizontally (within the active horizon of the peat deposit) – by areas up to 100–200 m.

Evaluation of Urbanization Influences on Beach Sediment Contamination with Heavy Metals Along the Littoral Zone of Alexandria City, Egypt

The western coastal area of Alexandria City, Egypt, faces significant environmental challenges due to heavy metal (HM) contamination in beach sediments, driven by intensive urbanization, tourism, commercial harbors, and industrial activities. Therefore, this study focuses on geochemically assessing HM levels in sediment samples from 28 sites and employed various descriptive and multivariate statistical approaches, pollution indices, and sediment quality guidelines (SQGs) to identify pollution hotspots, define contamination grades, and assess the quality of beach sediments. The average concentrations of Cd, Co, Cr, Cu, Pb, and Zn were 25.7, 30, 2.2, 7.5, 2.9, and 8.0 times, respectively, compared to the geochemical background (carbonate sedimentary rocks). et al.-Hanuvil Beach, relatively elevated contents of these metals were recorded. In addition, samples showed Zn levels higher than the corresponding probable effect concentration (PEC) and effect range medium (ERM) values, suggesting adverse impacts on biota. The principal component (PC) analysis revealed the anthropogenic origin of Cd, Co, and Pb in PC1, the mixed origin of Cr, Cu, Mn, and Zn in PC2, and the natural source of Fe in PC3. According to the applied single pollution indices, HM contamination grades were ranked in ascending order of Mn < Fe < Cr < Cd < Cu < Pb < Zn < Co. In conclusion, the HMs (Cu, Zn, Cd, Co, Pb, and Cr) in the study area are anthropogenic, attributed mainly to untreated discharge of municipal and industrial wastewater and solid wastes, atmospheric deposition of air pollutants, and tourism activities.

Removal of Methylene Blue from Aqueous Solution through Adsorption and Heterogeneous Fenton Reaction using Iron Oxides Produced by Different Methods

Direct discharge of industrial wastewater containing dyes into water bodies has contributed to the scarcity of drinking water. As environmental legislation becomes stricter, it is increasingly important to develop efficient methods for wastewater treatment. Traditional methods are commonly costly and have limited efficiency. This study aimed to prepare iron oxides via different synthetic routes and evaluate the effect of synthesis method on the efficiency of these materials as adsorbents and heterogeneous Fenton catalysts for the removal of methylene blue from aqueous solution. Iron oxides were synthesized by non-hydrolytic sol–gel (NHSG) and co-precipitation (CP) methods, followed by hydrothermal treatment for different times. CP oxides demonstrated high efficiency in dye adsorption, particularly the sample subjected to hydrothermal treatment for 6 h (CP-R6). This sample achieved 94.04% removal in 120 min. NHSG materials, by contrast, were less effective. The CP series of materials showed superior catalytic performance in heterogeneous Fenton experiments, with CP-R6 reaching 98.79% decolorization in 240 min. X-ray diffraction analysis indicated that iron oxides were composed of crystalline hematite and maghemite. Scanning electron microscopy revealed that CP materials were more porous and homogeneous than NHSG materials. The results demonstrated the efficiency of the developed iron oxides in removing methylene blue via adsorption and heterogeneous Fenton degradation and clarified how synthesis method influences adsorptive and catalytic properties.

Terminal deoxynucleotidyl transferase-mediated CRISPR sensing platform for simple and point-of-care detection of cobalt pollution

The excessive use of cobalt in various chemical industries and arbitrary discharge of industrial wastewater have led to increased cobalt pollution in soil and water resources, increasing the risk of human exposure to high concentrations of cobalt and necessitating an urgent need for on-site monitoring platform for cobalt pollution. In this study, the terminal deoxynucleotidyl transferase (TdT)-CRISPR platform has been developed. In this platform, cobalt as a cofactor of TdT, can significantly improve the tailing efficiency of TdT-mediated extension. Therefore, when cobalt is present, the detection probe can be extended with poly(T) tails through the TdT-mediated extension, which can be subsequently served as the DNA activator for Cas12a, leading to the cleavage of fluorescence reporter molecules and triggering turn-on fluorescence signals. Consequently, this dual amplification sensing strategy of TdT-CRISPR platform demonstrated exceptional sensitivity (0.83 nM) and high specificity for cobalt over other ions. Furthermore, the method was successfully employed for the detection of cobalt in tap water and river samples. CRISPR-lateral flow assays (CRISPR-LFAs) were evaluated in this study for the simple and point-of-care detection of cobalt pollution. The assays are capable of detecting cobalt concentrations as low as 50 nM, which is significantly lower than the environmental standards of 16.9 μM, through strip analysis with the naked eye. These results commonly suggest that the TdT-CRISPR platform holds significant promise for monitoring cobalt pollution, providing a robust and sensitive solution for on-site detection and contributing to the mitigation of cobalt contamination risks in environmental matrices.

Chloride-salt separation type nanofiltration membranes for efficient crude salt refinement

Application of unrefined crude salt not only leads to a serious equipment scaling and a low product quality, but also increases operational risks and poses health hazards. Therefore, it is essential to refine crude salt prior to its use. However, traditional methods of crude salt refinement are energy-intensive and probably produce additional chemical by-products. In this work, membrane technology was used to accomplish the refinement of crude salt due to its unique characteristics, such as environmentally friendly and lower energy consumption. To improve the separation performance, the membranes were fabricated by simply adjusting the aqueous monomer concentration. For single-salt feed, the membrane (M10) prepared with a high ratio of 10 exhibited excellent salt rejection due to the formation of a thicker and denser PA layer. And it owned a superior MgCl2/NaCl selectivity of ∼22.0, demonstrating that the membrane can achieve outstanding selectivity for mono-/divalent ions. The selectivity of Mg2+/Na+ increased to ∼23.5 for bi-salt feed and further improved to 66.2 for multi-salt feed due to the stronger charge shielding effect. Most importantly, the membrane was also successfully applied in the refinement of crude salt. When using crude salt (NaCl 30 g/L, purity 0.90) as feed, the M10 exhibited both excellent retention of bivalent ions and permeation of univalent ions, resulting in the corresponding Mg2+/Na+ selectivity up to ∼251.6 and the tremendous enhancement in the Na + purity of ∼0.997. This work offers a feasible strategy for crude salt refinement, and could expand to some other potential applications such as resource utilization in the salinization industry and zero-liquid discharge of industrial wastewater.

Status, Sources, and Risks of Heavy Metals in Surface Sediments of Baiyangdian Lake and Inflow Rivers, North China

Baiyangdian Lake, recognized as the largest freshwater body in northern China, plays a vital role in maintaining the regional eco-environment. Prior studies have pointed out the contamination of sediments with heavy metals, raising concerns about eco-environmental challenges. Therefore, it is imperative to evaluate the current pollution levels and ecological threats related to heavy metals found in the sediments of Baiyangdian Lake as well as in its inflow rivers. In May 2022, surface sediments with a depth of less than 20 cm were analyzed for Cu, Zn, Pb, Cr, Ni, As, Cd, and Hg to determine the pollution status, identify sources of pollution, and evaluate potential ecological risks. A range of evaluation methods used by predecessors such as geo-accumulation index (Igeo), enrichment factor (EF), ecological risk index (RI), sediment quality guidelines (SQGs), positive matrix factorization (PMF), absolute principal component score-multiple linear regression model (APCS-MLR), chemical mass balance (CMB), and UNMIX model were analyzed. After comparison, multi-methods including the geo-accumulation index (Igeo), absolute principal component score-multiple linear regression model (APCS-MLR), ecological risk index (RI), and sediment quality guidelines (SQGs) were utilized this time, leading to a better result. Findings reveal that pollution levels are generally low or non-existent, with only 1.64% of sampling sites showing close to moderate pollution levels for Cu, Pb, and Zn, and 4.92% and 1.64% of sites exhibiting close to moderate and moderate pollution levels for Cd, respectively. The main contributors to heavy metal presence are pinpointed as industrial wastewater discharge, particularly Cu, Zn, Pb, Cd, and Hg. The ecological risks are also relatively low, with 4.92%, 1.64%, and 1.64% of sampling sites demonstrating close to moderate, moderate, and strong risks in the inflow rivers, respectively. Additionally, only one site shows moderate potential biological toxicity, while the rest display non-toxicity. These findings will update our cognition and offer a scientific basis for pollution treatment and ecosystem enhancement for government management.

A review of the wetland's restoration mechanisms and its economic and social benefits

ABSTRACT Our earth has given many ecosystems that will heal themselves from the degradations. One of those ecosystems is the wetland, which is a precious natural sponge, naturally purifying and replenishing the water, head off from the flood, and mainly giving tremendous biodiversity to the flora and fauna. However, human activities are degrading the wetlands and polluting them indiscriminately with solid wastes and domestic and industrial wastewater discharge. With the Ramsar Convention on Wetlands, nations around the world have acknowledged the critical benefits of wetland restoration and development. In this review article, we contributed to address the general wetland policies in the world, both nationally (India) and regionally (Tamil Nadu). In this paper, we will be discussing the reviews on the characteristics of wetland ecosystems, indices of biodiversity, risks to the wetland's restoration tactics, its main obstacle, and the financial advantages of wetlands. After clearly analyzing 226 previous research and review articles, a clear coherence between the explored hypothesis of wetland restoration mechanisms and the resulting economic and social benefits was arrived. Our findings indicate that effective restoration not only enhances ecosystem services but also leads to significant economic gains and improved community well-being. This alignment underscores the importance of investing in wetland restoration for sustainable development.

Flotation separation of maghara coal in Egypt for the removal of hazardous Cr(VI) from industrial wastewater

ABSTRACT Due to its serious toxicity, wastewater contaminated with hexavalent chromium (Cr(VI)) has become an increasing environmental concern. Herein, a novel flotation separation of maghara coal in Egypt for Cr(VI) removal was proposed to separate coal to three types of maceral group fractions including liptinite, vitrinite, and inertinite via controlling in density as a function in the degree of coalification. The results implied that the activated inertinite macerals (AIM) have the highest carbon and lowest nitrogen levels among the entire maceral groups. The Langmuir isotherm model exhibited a high adsorption capacity of the AIM sample (1226. 21 mg/g) compared to pre-flotation separation sample (877.55 mg/g). Therefore, the flotation separation of maghara coal played a vital role in the Cr(VI) removal. The residuary concentration of Cr(VI) after adsorption onto AIM was close to 0.037 mg L−1 at pH = 2, which satisfies the industrial wastewater discharge standard. In addition, the removal of Cr(VI) onto AIM surface has been demonstrated to be highly effective via the adsorption and reduction process. The oxygen-containing functional groups could strengthen the interaction between Cr(VI) and AIM surface through the reducing reactions. The accelerating effect of organic acids was investigated for the capture of Cr(VI) and the efficiency in the presence of tartaric acid was improved up to 99.96% within 48 h compared to other organic acids. Therefore, this research provides a sophisticated strategy for separating coal to highly efficient adsorbents for wastewater remediation.

Dual carbon isotopes (δ13C and Δ14C) were used to reveal the main sources and input fluxes of dissolved inorganic carbon in a karst reservoir in winter

In karst areas, the dissolved inorganic carbon (DIC) concentrations in aquatic systems are typically higher than that in non-karst areas due to intensive carbonate rock weathering. Understanding the sources and input fluxes of DIC in karst reservoirs is crucial for regional carbon cycle studies. This study utilized dual carbon isotopes (δ13CDIC and Δ14CDIC) to estimate the contribution rates and input fluxes of DIC from various sources in Aha Reservoir (AHR), located in southwestern China. Our results indicated that the DIC concentrations (22.33–32.79 mg L−1) and δ13CDIC values (−10.02‰ to −8.55‰) were nearly homogeneous both vertically and laterally in the reservoir (p > 0.05). The Δ14CDIC values (−246.31‰ to −137.86‰) were homogeneous along the vertical profile (p > 0.05), but showed significant horizontal variation (p < 0.05), with values decreasing from −149.57 ± 10.27‰ to −232.85 ± 2.37‰ at the mouths of the inflowing rivers. We found that the inflowing rivers were the primary DIC sources to AHR, contributing 70% of the total input, while groundwater and atmospheric CO2 contributions were relatively minor, at 18% and 12%, respectively. The Jinzhong River (JZR), influenced by industrial and domestic wastewater discharge, contributed the largest DIC input flux at 2.01 t/(km2·mon). In contrast, the Youyu River (YYR), influenced by acidic mine drainage, and the Baiyan River (BYR), influenced by agricultural activities, contributed relatively smaller DIC input fluxes of 1.29 t/(km2·mon) and 1.03 t/(km2·mon), respectively. This study highlights the significant impact of anthropogenic activities on DIC input in AHR, with industrial and domestic wastewater discharges having a greater influence than agricultural activities and acidic mine wastewater inputs. These findings underscore the critical need to manage and mitigate the impacts of human activities on karst reservoir ecosystems.

Development of a Novel Adsorbent Derived from Olive Mill Solid Wastes for Enhanced Removal of Methylene Blue.

Industrial wastewater discharge, tainted with hazardous substances, including dyes like methylene blue (MB) from the textile sector, further emphasizes the need for water treatment to produce safe drinking water. This study explores the potential of olive mill solid waste, an abundant and cost-effective agricultural waste in Mediterranean regions, to yield high-quality activated carbon (AC) with zinc chloride activation for MB adsorption. The activation process, carried out at a modest temperature of 500 °C without the need for an inert atmosphere, resulted in AC with remarkable characteristics, boasting a substantial surface area of 1184 cm2·g-1 and a total pore volume of 0.824 cm3·g-1. Extensive characterization of the AC was carried out through a large range of surface techniques. The pH of the solution had minimal influence on MB adsorption, the maximum removal was 95%, which was under slightly acidic pH conditions (5.8), and the adsorbent dose was 0.4 g·L-1 for a 50 mg·L-1 MB concentration. Equilibrium data pertaining to MB adsorption were subjected to fitting with different models, namely Langmuir, Freundlich, and Temkin. Notably, the Langmuir model exhibited the best fit, revealing a maximum monolayer adsorption capacity of 500 mg·g-1 at 25 °C, and the adsorption kinetics closely followed a pseudo-second-order model.

Pollution of Toxic Heavy Metals and Ecological Risk in Mirzapur Industrialized Zone of Gazipur, Bangladesh

The Mirzapur industrial area in Bangladesh underwent an assessment for soil contamination with toxic heavy metals such as Cr, Cu, Cd, Pb, &amp; Ni. Pollution in the region attributed to the discharge of industrial wastewater into irrigation canals and lakes. The prevalent contaminants were found to be Cr, Cu, and Ni, followed by Pb and Cd. The geo-accumulation index (Igeo) indicated that the area was classified as experiencing mild to moderate contamination, with Ni exhibiting the highest levels, followed by Cd, Cu, Cr, and Pb. Both the pollution load index (PLI) &amp; contamination factor (CF) showed a moderate level of pollution, while the potential ecological risk index (RI) suggested a moderate ecological risk in this area. The study concluded that the Mirzapur industrial area in Bangladesh exhibited moderate heavy metal contamination, posing a moderate environmental risk. J. of Sci. and Tech. Res. 5(1): 45-52, 2023

Assessing the impact of green patents on pollution reduction: A micro-level study of Chinese industrial firms

As global warming and environmental degradation escalate, policymakers worldwide increasingly advocate for the development of green patents. However, there is ongoing debate regarding the effectiveness of green patents in actual pollution reduction. Some studies suggest that firms may engage in green patenting activities to align with government and market expectations rather than achieving substantive breakthroughs in pollution reduction. In light of this, it is crucial to examine the impact of green patents on pollution reduction. This study employs a PSM-DID model to analyze the impact of green patents on pollution emission intensity using plant-level data from Chinese industrial firms. The results demonstrate that with an average increase of 1% in the number of green patents, the industrial waste gas emission intensity and industrial wastewater discharge intensity decreased by 4.74% and 8.68%, respectively. Furthermore, pollution treatment facilities were found to be more effective than green patents during the sample period. On average, the contribution of waste gas treatment facilities and wastewater treatment facilities in pollution reduction is 3.33% and 9.79% higher than that of green patents. These findings suggest that firms should adopt a balanced approach when making decisions on pollution reduction. Further analysis shows that the pollution reduction effect of green patents is partly at the expense of the total factor productivity of firms. This trade-off highlights the need for policy interventions to support firms in integrating green technologies without compromising productivity. This study underscores the emphasizes of transitioning from end-of-pipe pollution control to green production processes to achieve sustainable development in China.

A numerical investigation on the dynamics of particle deposition and fouling on a vertical falling film pipe

The zero liquid discharge process is designed to eliminate the discharge of industrial wastewater into the environment, addressing significant environmental concerns that have emerged in recent decades. Falling film evaporator is one of the primary technologies employed in these systems. As observed, there is a noticeable lack of research numerically simulating these phenomena in a vertical pipe including falling film flow. In the present study, an effort has been made to address the existing research gap by conducting numerical simulation of particles deposition and fouling phenomena in a falling film flow in a three-dimensional vertical pipe using computational fluid dynamics. Continuous phases which contain two non-penetrating fluids, i.e., air and water, are simulated using volume of fluid multiphase model and the large eddy simulation turbulence model. Meanwhile, particles motion has been tracked utilizing discrete phase model. Water film enters the pipe with a thickness of 3.7 mm and an inlet velocity of 1 m/s, and particles with a density of 3110 kg/m3 are injected through the water inlet surface in various cases, each with different diameters. As observed, with an increase in particles diameter from 5 to 15 μm, the asymptotic total fouling mass has increased over 14 times, reaching from 0.016 to 0.18 kg/m2, and the total number of deposited particles has also increased. By increasing the fluids inlet velocity from 1 to 1.5 m/s, the total number of deposited particles has decreased throughout the pipe wall, and the total fouling mass has experienced a reduction of 55.8 %.

Heavy Metal Accumulation in Sediments of a Non-Perennial River in South India: Implications for Ecology and Human Health – A Multi-Index and Statistical Assessment

ABSTRACT The present study assessed the heavy metal pollution in sediment samples collected from the Noyyal River basin (river and lake sediments) during the monsoon and summer seasons. The geo-accumulation index (Igeo) categorizes metals as extremely polluted during monsoon and heavily contaminated to extremely contaminated during summer. The enrichment factor (EF) of metals Mn during monsoon and Cd during summer indicates extremely severe enrichment (EF > 50) and Mo exhibited very high contamination (CF > 6) throughout the basin during monsoon. The average risk index of heavy metal in the basin followed the order Cd (164.15) > Ni (14.82) > Co (4.84) > Cr (2.55) > Cu (1.89) > Zn (1.38) > Mn (0.40) during monsoon and Cd (153.07) > Ni (7.96) > Cu (5.13) > Co (4.63) > Cr (1.89) > Zn (1.21) > Mn (0.3) during summer showing that the PERI of each element was minimal except for Cd. Adverse health-related effects are confirmed by the cumulative total hazard index (THI) for children with HQ ingestion and HI values >1 in all sample locations over both seasons. Principal component and cluster analysis show metals accumulate in sediments mainly through industrial wastewater discharge and also experience significant natural source weathering through rainfall runoff. This research emphasizes the need for enhanced wastewater treatment facilities in metropolitan areas situated along the Noyyal River to potentially reduce the release of heavy metals from both domestic and industrial sources.

G‐C3N4 Based Composite Materials for Photo‐Fenton Reaction in Water Remediation: A Review of Synthesis Methods, Mechanism and Applications

AbstractOrganic pollutants in water pose significant challenges for water treatment due to their harmful effects and resistance to conventional methods. The rapid increase in industrial wastewater discharge has heightened the need for effective pollutant degradation techniques. Photo‐Fenton technology, an advanced oxidation process, has gained attention for its ability to degrade a wide range of organic contaminants in water. Developing high‐performance photo‐Fenton catalysts is therefore crucial. Graphitic carbon nitride (g‐C3N4) stands out in this field due to its suitable energy band structure, stable properties, and simple synthesis process. However, its application is limited by a low specific surface area, narrow light absorption, and high recombination rate of photogenerated carriers. This review provides a concise overview of current research on g‐C3N4 in photo‐Fenton technology, covering synthesis methods, modifications, and the mechanisms enhancing its photo‐Fenton activity. It also highlights key factors affecting g‐C3N4’s effectiveness in photo‐Fenton reactions and discusses recent advancements in its applications. The review concludes with an analysis of existing challenges and potential future directions for g‐C3N4‐based photo‐Fenton catalysts, offering theoretical insights to advance their industrial use in wastewater treatment.

Synergistic enhancement of oil-water separation and flame retardant properties of melamine sponges based on 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and perfluorinated compounds

Facing the escalating issue of industrial wastewater discharge and its profound environmental repercussions, the creation of novel sponge materials that excel in oil-water separation while incorporating flame retardancy becomes critically urgent. Despite their superior absorption capabilities, conventional oil-water separation sponges typically overlook flame retardant features, a limitation that curtails their applicability. To address this gap, we have developed a multifunctional hydrophobic sponge through a sophisticated multi-step chemical self-assembly process. This method grafts 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and perfluorinated compounds onto melamine foam (MF), yielding a composite material designated as DOPO-PF@MF. DOPO-PF@MF boasts a dual functionality of hydrophobicity and flame retardance. Its modified surface exhibits a pronounced hydrophobic-lipophilic balance, with a static water contact angle of 134°. It also displays favorable wetting characteristics towards various organic solvents, such as methanol, ethanol, dimethylformamide, dichloromethane, and hexane. This material demonstrates an impressive adsorption capacity for these solvents, with the adsorption-desorption capacity for ethanol remaining consistent over ten cycles. Furthermore, DOPO-PF@MF efficiently separates emulsions of methylene chloride and water, showcasing its versatility. Moreover, DOPO-PF@MF exhibits commendable chemical resilience under extreme temperatures, ranging from 0 °C to 100 °C, and withstands both acidic and alkaline conditions (pH 1–14), preserving its structural integrity against corrosive substances. Most notably, it surpasses unmodified melamine foam in flame retardancy. The incorporation of DOPO fortifies the material's resistance to high-temperature ignition, effectively inhibiting flame propagation and reducing burn rate, enhancing safety measures.

Assessment of water quality in wells and springs across various districts of Taza City, Morocco.

The aim of this study is to assess groundwater pollution in the city of Taza, Morocco. This was accomplished through hydrochemical and biological investigations, focusing on analyzing the physicochemical and bacteriological parameters of groundwater. Water samples were collected from wells and sources within Taza City on a monthly basis during the spring and summer of 2023. These samples were subjected to analysis to identify physicochemical and bacteriological characteristics. The findings revealed multiple contaminations, primarily stemming from two sources: significant microbial pollution observed in 100% of samples due to runoff percolation and discharge of domestic and industrial wastewater, and varying degrees of chemical pollution observed across all samples. The results underscored deviations from national standards, notably in parameters such as dissolved oxygen, nitrate, and nitrite concentrations. These parameters exhibited values either lower or higher than the established norm.