Water, Air, & Soil Pollution最新文献

This study provides the first polymer-specific baseline assessment of microplastic (MP) contamination (0.15–5.0 mm) in four contrasting freshwater systems in Uzbekistan: the urban Karasuv Canal, glacier-fed Chirchik River, agriculturally influenced Sangzor River, and closed-basin Lake Tuzkon. Using a Microshup sampling device, stereomicroscopy, and Raman spectroscopy, we quantified MP concentrations, characterized particle morphology and color, and identified polymer types. Among the 480 confirmed MPs, microfibers (45%) and fragments (35%) predominated, with transparent (50%) and blue (30%) particles being the most common. MP concentrations ranged from 1.4 particles m⁻³ in the Chirchik River to 2.4 particles m⁻³ in Lake Tuzkon, while the highest relative load per water unit occurred in the Sangzor River, likely linked to agricultural runoff. Polymer analysis revealed polyethylene terephthalate (PET) and polypropylene (PP) as the dominant polymers, with greater polymer diversity in Lake Tuzkon. The results reveal that hydrological conditions, land-use patterns, and waste management practices jointly influence the distribution of microplastics across Uzbekistan’s freshwater ecosystems. This study establishes an essential regional baseline for Central Asia and highlights the pressing need for continuous monitoring, improved waste management strategies, and expanded research that includes sediment assesment, finer plastic fractions, and ecotoxicological risk evaluation.

Municipal solid waste incineration fly ash (MSWI FA) leachate (FAL) is a potential source of heavy metal pollution, but its bioaccumulation and aquatic toxicity remains poorly characterized. In this study, FAL collected from a major incineration plant in Chongqing, China, underwent residual organic removal, followed by heavy metal (HMs) speciation analysis via ICP-MS and bioaccumulation assessment using zebrafish. Results identified the primary HMs in FAL descending order: Cu > Zn > Pb > Cr > Ni > Cd, while bioconcentration factors (BCFs) ranked Cd > Ni > Cu > Zn > Pb > Cr, revealing Cd's exceptional bioaccumulation capacity despite its low environmental concentration. Additionally, zebrafish embryos were exposed to FAL (> 500 mg/L, w/v; total heavy metals: 496.99 ± 20.1 μg/L) induced severe developmental toxicity, including increased mortality, delayed hatching, and morphological malformations. While > 50 mg/L FAL (> 48.9 ± 2.7 μg/L total heavy metals) caused locomotor deficits with swimming distance reduced by 45 ~ 90% and velocity by 58 ~ 85%. It also induced cardiorespiratory defects, with pericardial edema increasing 6 ~ 14-fold, and impaired swim bladder inflation. Mechanistically, FAL triggered excessive reactive oxygen species (ROS) in zebrafish, leading to blood–brain barrier disruption and neuronal apoptosis by upregulating p53 and Bax gene expression. Antioxidant glutathione (GSH) partially rescued locomotor activity by 68.3%. Collectively, our findings demonstrate that MSWI FA leachate, even with low heavy metals, endangers aquatic organisms and potentially human health via oxidative stress, highlighting the need for region-specific regulations to mitigate its environmental risks.

Graphical Abstract

With the acceleration of urbanization and industrialization, water pollution is becoming more and more serious. Because the technologies of traditional wastewater treatment have limited efficiency of pollutant removal, such as nitrogen (N) and phosphorus (P), heavy metals, antibiotics, and microplastics, the performance of wetland in pollution removal has become a research hotspot. However, there are few summaries of development trend and regional distribution of the performance of wetland in pollutionremoval. In thisstudy, VOSviewer software and the R package “bibliometrix” were used to systematically visualize literatures on the performance of wetland in pollution removal in the Web of Science Core Collection (WoSCC). The results of our bibliometric analysis revealed a significant increase in annual publications, with the output in Phase II (2010–2023) being 5.5 times that of Phase I (1995–2009). Research hotspots have evolved from an initial focus on nutrient (N, P) and heavy metal removal in Constructed wetlands (CWs) to a recent emphasis on emerging contaminants (ECs) remediation. A regional analysis indicated that Asia accounted for 73.8% of the studies in 2023, with China being the dominant contributor. While CWs constituted the majority (56%) of studied wetland systems in 2023, natural wetlands received substantial attention (41%), highlighting their significant pollutant removal capabilities and ecological benefits. This review synthesizes the key factors influencing pollutant removal in CWs and discusses the inherent advantages of natural wetlands, concluding with an outlook on future challenges and the potential for intelligent wetland development. This study provides insights and a systematic overview that can inform the optimization of wetland technologies for pollutant removal and help identify future research directions.

Water is essential for the survival of human existence. The rapid urbanization in the Old Mahabalipuram Road (OMR) region has led to groundwater stress. It is crucial to thoroughly analyse the physical and chemical characteristics as well as the locations with high potential for groundwater in the OMR region. Groundwater samples are routinely collected to assess the water quality. The Piper linear diagram provides the evidence of the presence of significant ions in the study region. The main physiochemical parameters that affect water quality are Total Dissolved Solids (TDS), Chlorine, HCO₃ and Total Hardness. To categorize the Groundwater Potential Zones (GWPZ), Analytical Hierarchical Process (AHP), GIS, and Remote Sensing techniques are used and five classes from extremely high to very low category were classified. Weighted overlay analysis was performed to map the groundwater potential zones of the study region. The results indicate that the coastal areas of OMR exhibit a significantly low potential, but the central region of OMR has a relatively high potential. The study also investigates the water quality aspects associated with GWPZ. The research work has the potential tool for the planning and management of groundwater resources in the OMR region.

Heavy metal (HM) contamination in agricultural soils poses a critical threat to food safety, particularly in vegetable production systems where direct human exposure occurs through consumption. Vegetables grown in contaminated soils often accumulate elevated levels of toxic metals such as lead, cadmium, chromium, and arsenic, as well as excessive zinc, increasing dietary and public health risks. Conventional remediation methods are frequently costly, inefficient, or environmentally unsustainable. Biochar has emerged as a promising, sustainable amendment for reducing HM bioavailability; however, its effectiveness and mechanisms in vegetable-growing soils remain insufficiently understood. This review critically evaluates biochar’s remediation potential, associated risks, and practical challenges, and outlines future research and policy priorities for safe and sustainable vegetable production. While biochar’s physicochemical traits—such as high surface area, alkalinity, and cation exchange capacity—facilitate metal immobilization through adsorption, ion exchange, and precipitation, remediation outcomes vary widely with production conditions and application rates. Potential drawbacks include nutrient immobilization or the remobilization of elements such as arsenic and chromium (VI). Broader adoption is further limited by variability in biochar quality, scarce long-term field data, high production costs, and weak policy support. Strengthening biochar governance through quality standards, financial incentives, and integration into soil health and carbon sequestration programs is essential to enhance feasibility and farmer adoption. By linking scientific evidence with policy and practice, biochar can serve as a scalable solution for safer vegetable production, improved soil resilience, and climate change mitigation.

A porous polyaniline-Fe₂O₃ nanocomposite (PANI-Fe₂O₃) with a specific BET surface area of 78 m² g⁻¹ was synthesized and evaluated for the removal of organic and inorganic contaminants from aqueous media. Methyl orange and hexavalent chromium [Cr(VI)] were selected as model pollutants to investigate the adsorption performance of the nanocomposite. Batch adsorption studies revealed maximum monolayer adsorption capacities of 367.64 mg g⁻¹ for methyl orange and 444.44 mg g⁻¹ for Cr(VI), with rapid uptake occurring within 100 min. The effects of adsorbent dose, initial contaminant concentration, contact time, solution pH, and temperature were also systematically examined. Thermodynamic analysis yielded negative change in Gibbs free energy (ΔG) confirming the spontaneous nature of the adsorption process. The nanocomposite also demonstrated favorable reusability, retaining substantial removal efficiency over five regeneration cycles. A plausible adsorption mechanism is proposed based on physiochemical attributes of the nanocomposite. Overall, the results demonstrate that the porous PANI-Fe₂O₃ nanocomposite is a promising and sustainable adsorbent for wastewater treatment, supporting improved water quality and contributing to broader environmental protection efforts. By enabling effective removal of hazardous dyes and heavy-metal species, this study directly advances Sustainable Development Goals 6 (Clean Water and Sanitation), 14 (Life Below Water) and 15 (Life on Land) and promotes the protection of aquatic and terrestrial ecosystems.

Soil contamination with heavy metals, particularly lead (Pb), poses significant environmental and health risks. Hydrochar, a carbonaceous material derived from biomass via hydrothermal carbonization, has shown potential in mitigating heavy metal bioavailability in contaminated soils. This study investigates the effectiveness of hydrochar derived from apple tree wood waste in immobilizing Pb and improving soil fertility. Two types of hydrochar, produced at 180 °C (H180) and 250 °C (H250), were applied at varying concentrations (0.5 wt.%, 1 wt.%, 1.5 wt.%, and 2 wt.%) to Pb-contaminated soils. Contaminated soil amended with hydrochar at varying concentrations were analyzed through a laboratory incubation experiment, and total and mobile Pb fractions in soil, as well as Pb accumulation in plants (Hordeum sativum), were evaluated. The results revealed that hydrochar amendments did not affect seed germination but influenced root growth, with H180 hydrochar stimulating root development in uncontaminated soil. Hydrochar application significantly decreased the mobile Pb fraction: in contaminated soil, H180 reduced Pb mobility by 37%, while H250 achieved a 52% reduction. Additionally, hydrochar amendment enhanced enzymatic activity in uncontaminated soil but had a mixed impact in Pb-contaminated soil, with some doses reducing dehydrogenase activity. Pb uptake by plants was dose-dependent, with higher hydrochar concentrations resulting in greater reductions in the bioconcentration and translocation factor values. The lowest Pb translocation was observed in soils treated with 2 wt.% of H250 hydrochar, highlighting its greater porosity and adsorption potential. These findings emphasize hydrochar’s potential as a sustainable soil amendment material for heavy metal immobilization and phytostabilization.

The present study evaluates, for the first time, the concentration and distribution of metals (Cd, Cu, Cr, Fe, Hg, Mn, Ni, Pb, Zn) in the sediments of the seabed of El Rincón and adjacent shelf areas, in the South Atlantic coast. Over a three-year period, coastal sectors were differentiated from offshore platform areas. The results revealed spatial and temporal differences, with concentration ranges of < LOD—2.58 mg/kg for Hg, < LOD—0.655 mg/kg for Cd, 24—638 mg/kg for Mn, 2.46—26.89 mg/kg for Cr, 2.02—13.43 mg/kg for Ni, 1.41—6.47 mg/kg for Pb, 0.44 -13.90 mg/kg for Cu, 5.85—36.05 mg/kg for Zn and 8300—43900 mg/kg for Fe. The concentrations of Cd were high and reached values ​​close to, but without exceeding, the maximum level recommended by the Sediment Quality Guidelines for marine and estuarine sediments (0.7 mg/kg), while Hg concentrations exceeded the Sediment Quality Guidelines (0.13 mg/kg) and the Probable Effect Level values (0.70 mg/kg). For Hg, the geoaccumulation index and the enrichment factor revealed highly contaminated sediments across all sectors during 2016. For Cd and Mn, only a minor anthropogenic impact was suggested through the enrichment factor, while the geoaccumulation indicated an absence of contamination by these metals. Overall, being an integrated index, the PLI indicated no metal pollution for the study area even when individual metrics for Hg revealed severe contamination. Therefore, long-term monitoring of this metal is crucial to assess potential ecological risks and support the development of environmental management policies to prevent potential adverse effects.

Graphical Abstract

Radon (^222Rn) and its progenies, lead-210 (^210Pb) and polonium-210 (^210Po), are naturally occurring radionuclides that pose serious public health risks when present in drinking water. Traditional treatment methods, including aeration, granular activated carbon (GAC), ion exchange, and coagulation, offer partial removal efficiency and face significant limitations, particularly in the selective elimination of radon progeny. Recent advances in nanotechnology have positioned graphene-based materials, including graphene oxide (GO), reduced graphene oxide (rGO), and their composites, as promising candidates for radionuclide remediation. These materials exhibit high surface area, tunable functional groups, and strong affinity for heavy metals and radioactive ions. This review critically examines the structure, properties, and adsorption mechanisms of graphene-based materials relevant to the removal of ^210Pb and ^210Po. We also analyze recent studies, performance-enhancing functionalization, and composite development with metal oxides, zeolites, and polymers. Although direct studies on radon progeny are limited, findings from chemically analogous systems provide strong evidence of efficacy. Future research should emphasize green synthesis, field-scale validation, and long-term performance in complex water matrices. Graphene-based adsorbents represent a scalable, sustainable, and highly adaptable solution for addressing the challenges of radionuclide contamination in drinking water.