Water, Air, & Soil Pollution最新文献

Speciation of arsenic contaminants plays an important role in environmental fate, risk assessment, and engineering management. It is essential to identify the arsenic speciation accurately. Synchrotron-based X-ray absorption spectroscopy (XAS), including X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS), provides detailed insights into arsenic oxidation states and local coordination environments. This review summarizes recent advances in the application of XAS to characterize both inorganic and organic arsenic species in environmental and biological systems. XANES was commonly used to distinguish arsenic oxidation states and identify complex arsenic-bearing minerals and organoarsenic compounds such as arsenopyrite (FeAsS) and dimethylarsinic acid (DMA). EXAFS provides quantitative structural parameters, bond lengths, coordination numbers, and adsorption configurations. The geometric structure includes binuclear bidentate, corner-sharing (²C), mononuclear monodentate, corner-sharing (¹ V), and binuclear bidentate, edge-sharing (²E) configurations. Applications of XAS to metal oxides, natural minerals, and metal–organic frameworks (MOFs) have revealed how surface chemistry and functional group modifications influence arsenic binding mechanisms. In biological contexts, XAS also identifies arsenic species in tissues and biomolecules. XANES and EXAFS enable comprehensive arsenic speciation analysis, supporting mechanistic understanding of arsenic transformation, mobility, and stability. This review highlights the critical role of XAS in arsenic speciation analysis and its potential in advancing environmental monitoring and remediation strategies.

To overcome membrane permeation selectivity defects and mitigate membrane fouling, a novel nanocomposite, UiO-66-NH₂/g-C₃N₅ (UNCN), was designed and synthesized. Notably, this composite overcomes the inherent limitations of UiO-66-NH₂ (limited visible light absorption) and g-C₃N₅ (low specific surface area). The optimal composite ratio was determined to be 3:7 through systematic optimization. The UNCN-3:7 nanocomposite was then embedded into the polyamide selective layer on polysulfone via in situ interfacial polymerization under optimal conditions, resulting in a thin film nanocomposite (TFN) Nanofiltration membrane. Characterization revealed that the UNCN-3:7 Nanocomposites were uniformly distributed within the polyamide (PA) matrix. The resulting TFN Nanofiltration membrane possessed an ultrathin, positively charged selective layer with enhanced hydrophilicity, evidenced by a reduction in water contact angle from 60.3° to 47.3°. It exhibited a 43% increase in pure water permeability compared to the unmodified thin film composite (TFC) membrane (52.7 vs. 36.9 L·m⁻²·h⁻¹·bar⁻¹), while maintaining an excellent Na₂SO₄ retention rate (> 96%). Furthermore, the membrane demonstrated excellent photocatalytic degradation performance, superior anti-fouling properties (flux recovery rate > 92%), and stable long-term operation. These results indicate that the construction of the novel UNCN nanocomposite Nanofiltration membrane presents an effective strategy to address membrane fouling issues.

Graphitic carbon nitride with defects and porous structure (dp-C₃N₄) was successfully synthesized by using silica microspheres as templates and treating graphitic carbon nitride (g-C₃N₄) through a simple pyrolysis process. Defects were introduced through the partial breaking of chemical bond during the pyrolysis process, which contribute to the generation of electron-hole pairs and reduce their complexation. Compared to pristine g-C₃N₄, dp-C₃N₄ has a narrow band gap, which enhances the absorption of visible light. Meanwhile, the design of the porous structure increases the specific surface area of the material, thus maximizing the exposure of active sites, which is conducive to the improvement of the substance transport efficiency during photocatalytic degradation. The experimental results confirmed that the efficiency of dp-C₃N₄ in degrading pollutants such as Rhodamine B (RhB), Methyl Orange (MO) and Bisphenol A (BPA) was significantly higher than that of g-C₃N₄. In addition, the dp-C₃N₄ exhibited effectively degradation for RhB in water under natural sunlight. The mechanism for the photocatalytic degradation of pollutants over dp-C₃N₄ via photocatalysis has also been explained

The excessive discharge of contaminants into water systems poses significant challenges to water quality, necessitating sustainable and efficient degradation methods. While numerous techniques exist for wastewater treatment, most photocatalytic catalysts face limitations in cost-effectiveness and practical scalability. Nickel oxide (NiO), a p-type semiconductor with strong oxidation capacity and chemical stability, has emerged as a promising candidate for organic pollutant degradation. However, its intrinsic wide bandgap (~ 3.6–4.0 eV)​ restricts pure NiO to UV light absorption​ (< 400 nm), limiting its solar-driven efficiency. Recent advances demonstrate that structural modifications, including heterojunction engineering and doping can effectively address these limitations by tailoring the NiO electronic structure and charge dynamics. Sulphur/Nitrogen (S/N) co-doping​ reduces the bandgap of NiO from 3.6 eV to 2.50 eV, enabling 98.9% degradation of methylene blue (MB) under sunlight within 60 min. Similarly, different heterojunction systems narrow the bandgap via enhanced charge separation. The hybrid carbon composites that create interconnected conductive networks, reduce charge-transfer resistance, and suppress electron–hole recombination, this approach primarily optimize surface reactions and charge migration pathways at the NiO interface. These modifications suppress electron–hole recombination (evidenced by photoluminescence quenching) and expand visible-light absorption into the 450–590 nm range. This review critically evaluates NiO electronic properties, heterojunction, doping, and hybrid carbon composites, highlighting how these strategies overcome intrinsic limitations. By integrating quantitative data on bandgap tuning and degradation kinetics, we provide a mechanistic framework for optimizing NiO-based photocatalysts toward sustainable environmental applications.

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The widespread use of tetracycline (TC) has led to its accumulation in aquatic environments, posing risks of antibiotic resistance and ecological toxicity, necessitating efficient wastewater treatment solutions. While photocatalysis, particularly using TiO₂, has shown promise, its practical application is limited by low efficiency and rapid charge recombination. To overcome these challenges, this work developed a novel ternary TiO₂@Ti₃C₂/ZIF-67 (T@M/Z) heterojunction photocatalyst through a facile hydrothermal process. T@M/Z-18 composite demonstrated exceptional photocatalytic performance, achieving 92.52% of TC removal and 77.05% of total organic carbon (TOC) mineralization under visible light after 90 min. Systematic studies optimized key operational parameters, revealing that a catalyst dosage of 0.5 g/L and an initial TC concentration of 15 mg/L yielded the highest degradation efficiency. The presence of anions (e.g., Cl⁻ and SO₄²⁻) enhanced TC removal, while humic acid (HA) exhibited a dual role, acting as a photosensitizer at low concentrations but inhibiting degradation at higher levels. The catalyst maintained excellent stability and reusability, with only a slight decline in performance after five cycles. Degradation pathways, identified through high-performance liquid chromatography-mass spectrometry (HPLC–MS) analysis, involved hydroxylation and N-demethylation, leading to reduced acute toxicity. These results highlight the potential of T@M/Z as a sustainable and efficient solution for antibiotic-contaminated wastewater treatment.

Indoor air pollution poses a significant health hazard in low-income neighborhoods with densely populated areas in Dhaka, due to low levels of ventilation and a lack of green space, leading to high exposure to fine particulate matter (PM2.5). This study was conducted to assess the potential of common house plants: Areca Palm (Dypsis lutescens), Rubber Plant (Ficus elastica) and Golden Pothos (Epipremnum aureum), which were tested in pairs to assess their association with the changes of indoor PM2.5 concentrations and the air quality index (AQI) during pre-monsoon, monsoon and post-monsoon seasons. The Areca Palm-Rubber Plant combination implies probable improvement, with a PM2.5 reduction of 18.8% (pre-monsoon), 17.0% (monsoon) and 25.4% (post-monsoon), which corresponds to a decrease in AQI values of 10–22 points consistent with a change in the initial air quality (IAQ) conditions from "moderate" to "good". Seasonal effects were the largest during the post-monsoon, when PM2.5 levels were lower in the ambient air. Species-specific leaf features may have affected removal efficiency: high transpiration rates and leaf structure accounted for the higher capture of the Areca Palm, whereas broad and waxy leaves may have promoted particulate deposition in the Rubber Plant. Repeated measures analysis of variance (RM ANOVA) suggested that there were significant differences in PM2.5 levels between plant pairings in all seasons (p < 0.05). Overall, the results suggest that strategic placement of house plants that are readily available could offer a nature-based intervention for improving indoor air quality to meet urban public health and sustainability targets (SDGs 3 and 11).

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Ammonia (NH₃) volatilization from agricultural soils is a major environmental concern. This study investigated the effects of solid manure compost (SMC) and liquid manure compost (LMC) on NH₃ emissions, considering the influence of soil properties, environmental factors, and crop characteristics. NH₃ volatilization was influenced by manure type, with LMC significantly increased NH₃ emissions due to its high moisture content, rapid nitrogen mineralization and substantial NH₄⁺ concentrations. Soil pH and electrical conductivity (EC) play crucial roles in regulating NH₃ emissions. Higher pH levels enhance the conversion of NH₄⁺ to NH₃ gas, whereas salt-induced stress inhibits nitrification, leading to the accumulation of NH₄⁺ in the soil. Lower NH₃ emissions in Chinese cabbage were accompanied by higher agronomic efficiency compared with potato. NH₃ emissions were noticeably influenced by environmental factors, particularly rainfall and temperature, with emissions being reduced by rainfall and intensified by higher temperatures. In terms of productivity, LMC enhanced crop yields, while the lower maturity of SMC limited its effectiveness as a fertilizer. This study highlights the interplay between manure compost application, soil properties, and NH₃ volatilization, emphasizing the importance of targeted management strategies to balance agricultural productivity with environmental sustainability.

The present study focused on investigating the individual and combined effects of polystyrene microplastics (MPs) with the heavy metal chromium (Cr) on the brine shrimp Artemia franciscana. The second instars of A. franciscana were exposed to fluorescently labeled polystyrene MPs (size 2 μm) at 0 (control), 1.1 × 10⁶_, 3.4 × 10⁶, and 5.8 × 10⁶ particles /L with and without Cr for 2 h to confirm the ingestion of MPs. Furthermore, A. franciscana was exposed to the same concentrations (0, 1.1 × 10⁶, 3.4 × 10⁶, and 5.8 × 10⁶ particles/ L) of non-labeled polystyrene MPs individually and combined with Cr at 0.46 mg/L for 21 days. Survival, growth, biochemical constituents, metabolic enzymes, antioxidants, lipid peroxidation, and Cr accumulation were evaluated during the 7th, 14th, and 21st days of exposure. The ingestion assay showed concentration-dependent ingestion of MPs by Artemia in both MPs alone and MPs with Cr exposure. Meanwhile, the toxicity study reveals a significant decrease in survival, growth, protein, carbohydrate, amino acid, and lipid levels in Artemia with significant increases in metabolic enzymes (glutamic oxaloacetic transaminase and glutamic pyruvate transaminase), antioxidants (superoxide dismutase and catalase) and lipid peroxidation exposed to both MPs and MPs with Cr compared to respective control and control with Cr (Cr alone) treatments, which shows biological and physiological impairment of Artemia. In addition, all MPs with Cr treatments produced a significantly greater impact on the studied parameters with increased Cr bioaccumulation, which suggests the synergistic toxicity of these MPs and Cr combination on Artemia.

Groundwater constitutes a vital water supply in the Zhanjiang region, and clarifying its chemical properties and quality is fundamental to the sustainable management of such resources. To address gaps in understanding hydrochemical features, water quality, and nitrate-related health risks of local groundwater, 29 samples were collected for analysis. A multi-method approach—incorporating Piper trilinear plots, Gibbs diagrams, isotopic assays, and ion ratio analyses—was applied to unravel hydrochemical compositions and their governing processes. Groundwater quality was evaluated using the entropy-weight water quality index (EWQI), while the human health risk assessment (HHRA) model quantified potential risks from nitrate (NO₃⁻). Results showed that both unconfined and middle confined groundwater were weakly acidic. Unconfined groundwater was dominated by HCO₃·SO₄ − Ca·Na and SO₄·Cl − Ca·Na types, whereas middle confined groundwater exhibited more diverse types with HCO₃ − Ca·Mg as the primary category. Rock weathering and cation exchange adsorption were key controls for both aquifers; additionally, unconfined groundwater was influenced by domestic pollution, and middle confined groundwater by agricultural activities. EWQI classified middle confined groundwater as "excellent" and unconfined groundwater as "good to excellent," with the former outperforming the latter. HHRA indicated higher health risks in unconfined groundwater, and children faced greater risks than adults. This study offers scientific support for sustainable groundwater exploitation and protection in Zhanjiang.

Levofloxacin is a persistent antibiotic that is difficult to degrade by conventional methods. In this study, a ZnAl-LDH composite modified with Garcinia mangostana extract was synthesized via microwave-assisted coprecipitation. The incorporation of bioactive compounds into the LDH matrix was confirmed by XRD and FTIR Spectroscopy, while a heterogeneous surface morphology was revealed by SEM, and an increased specific surface area was indicated by BET analysis. Adsorption tests showed optimum removal at pH 5 after 60 min, following pseudo-second-order kinetics and the Freundlich isotherm, with a maximum adsorption capacity of 119.048 mg g⁻¹. Thermodynamic analysis indicated that the adsorption process was spontaneous and endothermic, and regeneration tests demonstrated stability up to three cycles. These results suggest that the ZnAl-LDH composite functionalized with Garcinia mangostana extract is a promising and environmentally friendly adsorbent for pharmaceutical wastewater treatment.