Environmental Science and Pollution Research最新文献

Groundwater quality in most of the worldwide regions is found to be changed due to several factors. Therefore, present study deals with the hydrochemistry and quality characterization of the groundwater, in and around the Jawalamukhi Region, during three seasons. The groundwater aspects as covered in this study are very crucial for ensuring high-quality water supply to local people including lakhs of tourists regularly visit at the concerned regions. It is the rock-dominance, which is found to have a major influence on most of groundwater samples throughout the study period. The scatter plot between Ca²⁺ + Mg²⁺ with Na⁺ + K⁺ and total cations revealed carbonate minerals as a dominant source of ionic compounds rather than the silicates. Both of the HCO₃^– and Cl^– were determined as dominant anions for all the seasons, whereas Na⁺ and Mg²⁺ were dominant in the pre-monsoon (May), Ca²⁺ and Mg²⁺ during monsoon (August) and Ca²⁺ and Na⁺ during the post-monsoon (November). The occurrence of ion exchange played a definitive role behind the release of Na⁺ and the adsorption of Ca²⁺ in various samples. The comparison among (Ca²⁺  + Mg²⁺)–(Na⁺  + K⁺) and (HCO₃^– + CO₃^2–)–(SO₄^2– + Cl^–) showed the maximum samples of Ca²⁺–Mg²⁺–HCO₃^– water type during all seasons including some of Na⁺–HCO₃^– water type. Most of the parameters have natural sources of origin; however, the influences of anthropogenic activities cannot be denied. The NH₄⁺ and NO₃^– also mark the presence of anthropogenic impact at the groundwater of concerned regions. The water quality index characterized the groundwater quality good and excellent.

The ecotoxicological impact of petroleum refinery oily sludge (OS) on earthworms and their ecological functional dynamics is still unclear. As soil is the ultimate repository for the petroleum industries wastes, therefore, understanding the impact of OS on ecological indicator such as earthworms is crucial. This study evaluates the impact of OS on Eisenia fetida and its ecological functional dynamics under stress. For this, E. fetida was exposed to varying concentrations (10–100%) of OS mixed with cow dung and the growth parameters of the earthworms were assessed. Besides, soil health indicators in the earthworm processed OS substrates such as the activities of cellulase, phosphatase, amylase, urease, and dehydrogenase were assessed along with changes in bacterial numbers. The findings revealed that increasing concentration of OS significantly reduced the growth rate (1.54 ± 0.18 to − 5.76 mg wt worm⁻¹ day⁻¹), survivability rate (53.3% to 16.7%), and cocoon production capacity of the earthworm. Additionally, earthworms activity enhanced the bacterial population (total heterotrophic count, N₂ fixing bacteria, P and K solubilizing bacteria) and increased the activities of cellulase, phosphatase, amylase, urease and dehydrogenase by up to 3.8-fold and 3.5-fold, respectively in the substrate mixtures. Principal component analysis and canonical correlation analysis confirmed the role of earthworm in enhancing the enzyme activities and bacterial profiles. Finally, this study highlights the potential of incorporating ecological functional dynamics of the earthworm into ecotoxicity assays as a reliable indicator for pollutant tolerance.

As the global population grows, the introduction of pollutants into aquatic environments increases, posing significant health risks to humans and wildlife. Effective removal of harmful organic contaminants near discharge points can minimize the need for large-scale wastewater treatment technologies. Here, we developed a polydimethylsiloxane (PDMS) sponge with controlled pore size to enhance surface area and sorptive capacity, and further functionalized it to improve adsorption, catalytic capabilities and biocidal properties. The PDMS sponge was tested to remove a wide range of organic contaminants with diverse functionalities covering a Log K_ow range of 0.16 to 6.26. The PDMS sponge showed greater affinity for compounds with larger Log K_ow, likely due to the hydrophobic and lipophilic nature of PDMS itself. This adsorption behavior was found to be linear with respect to Log K_ow, with an R² = 0.8273. Functionalizing the PDMS sponge with activated charcoal significantly improved adsorption efficiency, both in the amount of compounds removed within 24 h and the time required to reduce the initial concentration by half. A photocatalytic experiment with TiO₂-PDMS sponge demonstrated enhanced degradation and removal of organic compounds under UV light. Furthermore, incorporating metallic copper into the PDMS sponge provided antimicrobial properties, reducing E. coli levels by an average of 42% after 4 h of contact. This is promising for bacterial deactivation at the generation point of runoff wastewater streams. These findings provide proof of concept that PDMS sponge composites can be used for remediation and cleanup of urban waters at their entry points.

With global warming, it is crucial to recognise that temperature changes can influence the ecotoxicity of pollutants in natural ecosystems. 4-Chloroaniline (4-CA) is an emerging contaminant due to its environmental persistence, bioaccumulation potential, and toxicity to aquatic organisms. This study intends to assess the effects of environmentally relevant concentrations of 4-CA (0.09–9.65 µg/L) on Daphnia magna under two temperatures: 20 °C (standard) and 26 °C (global warming). A 21-day reproduction assay evaluated the life-history traits and biomarkers related to oxidative stress, metabolism, neurotoxicity, genotoxicity, and cellular energy allocation. Results revealed an interaction between temperature and 4-CA exposure. At 26 °C, D. magna exhibited anticipation of reproduction and increased brood frequency but with fewer offspring per brood. Thermal stress also intensified metabolism and antioxidant defences, with elevated superoxide dismutase and glutathione peroxidase activities, suggesting a compensatory mechanism to mitigate oxidative damage. Genotoxicity was more pronounced at 26 °C, highlighting an increased risk of DNA damage. The combined stress of 4-CA and temperature negatively impacted energy allocation, reproductive success, and overall fitness. The results underscore the importance of incorporating climate change scenarios into ecotoxicological assessments of emergent contaminants, reinforcing the need to include 4-CA in the Water Framework Directive Watch List.

Bacillus and Pseudomonas are among the most extensively studied rhizobacterial genera. This meta-analysis demonstrates that their interactions with plants distinctly modulate heavy metal bioaccumulation. Specifically, Pseudomonas significantly enhanced zinc (Zn) accumulation in plants by 30.48%, while Bacillus increased nickel (Ni) accumulation by 51.72%. This stimulatory effect was consistent across various plant species and most pronounced within the first month after inoculation. Conversely, both genera reliably reduced arsenic (As) buildup under all conditions included in this meta-analysis. The accumulation of cadmium (Cd) exhibited a strong dependence on environmental and biological factors, showing a negative correlation with soil pH and a positive correlation with planting period. Furthermore, the impact of both rhizobacteria on Cd was highly plant-specific, varying significantly across different plant families. Therefore, selecting appropriate rhizobacteria-plant pairs and optimizing the planting period are critical for managing heavy metal uptake. Our study offers a comprehensive, quantitative framework of how key variables—soil pH, planting period, and plant species—influence this process. These insights provide a valuable foundation for designing effective phytoextraction strategies in contaminated soils.

This study proposes an efficient single-step treatment of lake water and municipal wastewater using an indigenously developed single-slope solar still with energy storage material. Two water sources are considered: (1) lake water, treated using both conventional (CSS-LW) and modified (MSS-LW) solar stills; and (2) municipal wastewater, treated with conventional (CSS-MWW) and modified (MSS-MWW) solar stills. The performance of solar still is experimentally analyzed and compared within the environmental conditions of Silchar, India (24.758°N, 92.792°E). The study evaluated the cumulative distillate output, energy and exergy efficiency, cost analysis, environmental impact, and water quality assessment of the solar stills. The total daily freshwater yield obtained from lake water distillation using MSS-LW is 4310.3 mL/day, representing a 38.7% increase compared to CSS-LW. Similarly, for municipal wastewater distillation, MSS-MWW yields 4180.2 mL/day, which is 36.8% higher than CSS-MWW. The energy efficiency for MSS-LW and MSS-MWW is 42.6%, and 40.85%, respectively, whereas the corresponding exergy efficiency is 3.92% and 3.84%. The CPL (cost per Liter) for MSS-LW is $0.011/L, while for MSS-MWW, it is $0.012/L, making both more cost-effective than CSS. Additionally, carbon credit savings improved by 38.5% for MSS-LW and 35.2% for MSS-MWW. The distilled water is clear and bacteria-free but have residual odor, making it suitable for irrigation and other non-potable uses and requires further treatment before domestic use. The results show that solar desalination is a sustainable wastewater treatment method, where thermal storage improves yield, lowers CO₂ emissions, and enhances cost-effectiveness.

Poor waste management has resulted in marine plastic litter increasing worldwide, and microplastics (MP) are now detected in all marine habitats. To better understand the distribution and ecological implications of MPs, we quantify the abundance of MP in all major marine habitats through a meta-analysis of data collected by systematic review. We extracted MP densities from 334 studies covering all major water column, intertidal, inshore and offshore seabed habitats from all continents. MPs are ubiquitous, and are present in all habitats in all continents with an average (± 95%CI) global density of 37,921 ± 13,925 particles m⁻² or 0.011 kg m⁻². MP densities in sediments are at least an order of magnitude higher than in the water column. Mean MP densities are highest in Asia, in tropical regions, and in mangroves. Although sedimentary habitats such as mangroves, saltmarshes, and seagrasses are often considered potential MP sinks due to high sedimentation rates, our analysis revealed that “Blue Carbon” habitats do not consistently exhibit elevated MP densities. We found that MP densities significantly increased with decreasing minimum detectable particle size. When we rescaled MP abundance to a minimum particle size of 0.01 mm to reduce the bias, this significantly increased the estimate of mean global MP density to 57,953  ±  17,442 particles m⁻². Scaling our estimated MP densities for each habitat to a global estimate of total marine MP that exceeds 1.5 billion tonnes, far surpassing expectations based on historical plastic production. This discrepancy suggests that published MP studies may disproportionately sample polluted sites, underrepresenting broader environmental conditions. However, in the thousands of locations sampled in this meta-analysis, the mean MP densities are high enough to expect fundamental biological processes, such as growth and reproduction, of marine fauna to be significantly negatively impacted.

Diatom-based monitoring offers a cost-effective and reliable tool for assessing water quality in developing countries. As natural bio-indicators, diatoms respond sensitively to environmental changes, making them ideal for long-term ecological monitoring. The current paper aims to examine the potential use of a diatom-based tool at the genus level (generic diatom index (GDI)), when flora at the species level is poorly known, for water quality assessment in the Cambodian river systems. Nineteen monitoring sites within the Sangker River catchment have been chosen for the study, while eleven physicochemical parameters and trophic diatom index (TDI) values have been used to predict the response of GDI values. Basic statistical tests and linear regression (LM) were used to describe the spatio-temporal variation of water quality based on GDI classification. A total of 78 diatom genera were recorded, dominated by biraphid taxa (67%), and 13 genera accounted for ~ 90% of total abundance. GDI classification indicated that 10% of sites were of good quality, 53% moderate, and 37% poor, with water quality declining downstream and in areas influenced by urban and agricultural activities. The linear model revealed that GDI was significantly associated with nutrient- and oxygen-related parameters (orthophosphate, dissolved oxygen, and chloride) and correlated strongly with TDI (adjusted R² = 0.96). Seasonal variation was also significant, highlighting the importance of temporal dynamics in tropical rivers. The current findings provided clear evidence of potential uses of diatom indices to assess the water quality in the Sangker River and other Cambodian river networks even at the genus level of determination. More importantly, diatom indices could be potential tools for long-term biomonitoring in developing countries like Cambodia, where the data and resources are limited. Consequently, the study suggested further investigation on the ecological sensitivity of diatom flora to localize their values, improving GDI classification performance within the tropical environment.