环境•农林最新文献

A comparative investigation of Co/Fe-LDH microstructures on the performance of PMS activation was conducted relying on typical ones of nanotube (LDH-1), nanosheet (LDH-2), and nanosphere (LDH-3). LDH-3 displayed the most excellent performance for sulfamethoxazole (SMX) degradation with a second-order reaction kinetic constant (k) reaching 0.040 L/mg/min, followed by LDH-2 (0.029 L/mg/min) and LDH-1 (0.024 L/mg/min) in turn. The quenching experiment of active species showed that although the microscopic morphology did not change the joint action of hydroxyl radical (OH), sulfate radical (SO₄^-) and singlet oxygen (¹O₂), it changed the reaction contribution (RC) of OH and SO₄^-. The activation performance and mechanism difference among LDH-1, LDH-2, and LDH-3 was attributed to the combined action of specific surface area, active site exposure, mass transfer, electron transfer, and microstructural confinement and surface-exposure effect. This work deepened the understanding of structure-induced mechanism in LDH/PMS system, providing theoretical support and practical basis for the precise design in further.

Airborne microplastics (MPs), defined as small plastic particles suspended in the atmosphere, pose a growing threat to environmental and human health. Their ability to travel long distances through air currents enables widespread contamination across both natural and urban environments. Major sources include the fragmentation of larger plastic debris, abrasion of synthetic textiles during washing, and degradation of household and industrial materials. Increasing evidence suggests that inhalation of airborne MPs may contribute to respiratory disorders, particularly among vulnerable populations. Understanding their sources, transport pathways, and toxicological effects is therefore essential for developing effective mitigation strategies. This review compiles and compares recent findings on the occurrence, characteristics, and environmental behaviour of airborne microplastics, alongside their interactions with other environmental compartments. It further highlights potential implications for human exposure, ecological impacts, and the need for standardized analytical and monitoring approaches. Moreover, there is increasing global concern that airborne microplastics may affect atmospheric transport and deposition dynamics and pose risks to human health through their transfer along food chains. By identifying current knowledge gaps and proposing directions for future research, this work aims to support a more comprehensive understanding of airborne microplastic pollution and its environmental health risks.

In present study, pollution load, ecotoxicological impact, and treatability potential of aquatic plants, viz. Eichhornia crassipes, Pistia stratiotes, and Spirodela polyrhiza evaluated for textile effluent in Jaipur region, Rajasthan, India. Wastewater quality of textile effluent exhibits high pollution load (mg/L) in terms of total suspended solids (TSS, 1986), biological oxygen demand (BOD, 72), chemical oxygen demand (COD, 2851), and metal contamination with concentration of Zn (6.41) > Cu (4.66) > Fe (4.61), Pb (4.58) > Cr (3.64) > Ni (3.53) > Cd (1.89). Evaluation of the Water Quality Index (WQI), Heavy Metal Pollution Index (HMPI), and Heavy Metal Evaluation Index (HMEI) reveals that textile effluent has detrimental effects on both water and soil quality. Additionally, evaluation with using geographical information systems (GIS) showed differences in water quality at different locations, and principal component analysis (PCA) indicated that soil quality varied significantly, with changes of 79.74% and 87.48% (p < 0.05). Luxuriant and fast growth of the selected aquatic plants, viz. Eichhornia crassipes, Pistia stratiotes, and Spirodela polyrhiza in diluted textile effluent and their potential for reducing pollution load demonstrate their feasibility to be use in developing low cost and sustainable technique for wastewater treatment. However, maximum reduction in pollution load observed in textile effluent treated with E. crassipes in terms of removal of TSS (31%), BOD (38%), and COD (41%). Present study provides new insights in integrating advanced techniques for ecotoxicological assessment using GIS and PCA and developing sustainable methods for treatment of textile effluent by exploring efficient aquatic plants.

This study proposes an inverse neural network (INN) framework to optimize aeration control in a sequencing batch reactor(SBR), addressing the dual challenges of energy efficiency and regulatory compliance in wastewater treatment. By integrating data-driven modeling with constrained optimization, the method dynamically adjusts aeration rates to maintain effluent ammonia concentrations below 5 mg/L while minimizing energy consumption. A back-propagation neural network (BPNN) establishes input–output correlations between process parameters and effluent ammonia concentration, constructing the inverse mapping foundation for the INN to resolve constraint-driven aeration optimization. Experimental validation across 20 operational cycles demonstrated a 20.3% reduction in energy usage compared to conventional fixed-rate aeration, achieving 95% compliance with discharge standards. The framework's penalty-based optimization and gradient clipping mechanisms ensure stability in applications, overcoming limitations of traditional proportional-integral-derivative(PID) controllers and mechanistic models. This work advances intelligent control strategies for sustainable wastewater management, offering a template for constraint-aware optimization in environmental engineering systems.

Soil potentially toxic element/metal contamination risks from abandoned mines and tailings require careful monitoring. This study analyzed the distribution and characteristics of potentially toxic element/metals in soil surrounding a historic copper mine and its tailings in the Tongshankou mining area, Daye, China. Results revealed that Pb, Cu, Zn, Cd, and As exhibited co-migration behavior. Most potentially toxic element/metals shared a similar distribution pattern, with higher concentrations found in the riverside area of the Oujiagang River, located farther from the mining and tailing sites. This indicates that surface runoff was likely the primary driver of potentially toxic element/metal migration. Furthermore, the study demonstrated that even after 20 years and despite the implementation of comprehensive protective measures, soil potentially toxic element/metal migration still poses potential health risks, as evidenced by the Hakanson index showing at least moderate ecological risk levels at 78.16% of sampling points. Therefore, long-term monitoring of soil potentially toxic element/metal status is recommended for old or abandoned mines to safeguard the surrounding environment.

Ensuring access to clean water through environmentally responsible methods has become a global priority. Chitosan, a biodegradable polymer sourced from natural chitin, has gained increasing attention for its potential as a green flocculant in water treatment. This mini-review summarises recent developments in the use of chitosan-based materials for contaminant removal via flocculation. Key factors, including the polymer’s molecular characteristics, functional groups, and chemical modifications, are discussed concerning their impact on flocculation efficiency. The review also outlines how chitosan and its derivatives have been tailored to enhance the removal of turbidity, dyes, heavy metals, and emerging pollutants, such as microplastics. Its low toxicity, biodegradability, and origin from renewable resources make it an ideal candidate for sustainable water purification technologies. Additionally, the review addresses current limitations in practical applications and identifies research directions to improve scalability and performance. By harnessing materials derived from nature to restore natural ecosystems, chitosan represents a promising step toward eco-conscious water management solutions.

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Rapid industrialization has exacerbated phenol-containing wastewater pollution, heightening the need for effective treatment of phenolic contaminants like phenol. While advanced oxidation processes (AOPs) such as the Fenton reaction are widely recognized for phenol degradation, conventional AOPs face limitations due to high H₂O₂ costs and iron sludge generation. Consequently, persulfate (PS)-based AOPs, known for their strong oxidizing capacity and environmental compatibility, have emerged as a research focus for phenolic wastewater treatment. Developing highly active, low-cost catalysts is crucial for efficient PS-AOPs. Single-atom catalysts (SACs), which maximize metal atom utilization and offer environmental friendliness, are particularly promising. This study introduces a system employing a porous carbon-supported single-atom iron catalyst (Fe–N–C) to activate peroxydisulfate (PDS) for phenol degradation. The Fe–N–C catalyst features a highly microporous, graphitic structure with uniformly dispersed, low-concentration surface iron atoms. The Fe–N–C/PDS system achieved over 97% phenol removal and over 95% COD reduction under optimal conditions, primarily through synergistic effects of hydroxyl radicals (HO^•) and singlet oxygen (¹O₂), which collectively accounted for more than 97% of the reaction contribution. The system exhibits excellent pH adaptability (pH = 2.75–11.00) and resistance to ionic interference, maintaining over 84% phenol removal in the presence of various anions.

This study presents the synthesis of an Fe₃O₄/rGO nanocomposite optimized with 27% (wt./wt.) Fe₃O₄ loading for the efficient adsorption of 4-nitroaniline (4-NA) and Cr(VI) from wastewater. Various characterization techniques were employed to evaluate the structural, textural, thermal, mechanical, and physicochemical properties of the synthesized nanocomposite. X-ray diffraction (XRD) and Raman spectroscopy confirmed the formation of inverse spinel Fe₃O₄ nanocrystals. Field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) revealed a quasi-homogeneous dispersion of Fe₃O₄ nanoparticles (average crystallite size: 10.67 nm) anchored onto rGO nanosheets. The presence of microporous networks in the nanomaterial was verified through N₂-BET analysis, which demonstrated a high specific surface area of 192.8 m²/g, facilitating the adsorption of harmful contaminants. Goniometric measurements confirmed the hydrophilic nature of the adsorbent. Batch adsorption experiments were conducted at 303 K with a fixed adsorbent dosage of 0.25 g/L to evaluate adsorption kinetics. Equilibrium adsorption times were determined as 4 h for 4-NA and 6 h for Cr(VI), both following pseudo-second-order kinetics. At pH 2 and 303 K, the nanocomposite exhibited remarkable maximum adsorption capacities of 264.21 mg/g for 4-NA and 324.56 mg/g for Cr(VI). High-resolution X-ray photoelectron spectroscopy (HR-XPS) analysis of spent samples revealed that the adsorption of 4-NA occurred predominantly through physical mechanisms, such as electrostatic attraction and π-π interactions between 4-NA molecules and the rGO moiety. In contrast, Cr(VI) adsorption was primarily achieved via synergistic chemical processes, including chelation with surface oxygen-functional groups (OFGs) and partial reduction to Cr(III), catalyzed by Fe₃O₄. With a saturation magnetization of 18.4 emu/g, the nanocomposite can be efficiently separated from aqueous media after adsorption using an external magnet. Furthermore, the nanocomposite demonstrated robust chemical and morphological stability, retaining its adsorption capacity and showing no significant iron leaching over four test cycles for both 4-NA and Cr(VI). This highlights its potential for sustainable wastewater remediation.

Microplastics (MPs), defined as plastic particles ≤ 5 mm in size, are pervasive in aquatic environments and pose significant risks to ecosystems and human health. Accurately tracing the sources of MPs is essential for effective pollution control. This review summarizes the potential sources, migration routes and distribution characteristics of MPs, focusing on the current progress in traceability models of MPs in aquatic environments. MPs in terrestrial and atmospheric environments, either primary or secondary emissions, migrate and finally enter aquatic environments through various pathways. Traceability research on MPs has evolved from subjective speculative analyses to data-driven statistical and machine learning models. Great improvements in the accuracy and interpretability of source apportionment have been made by learning from datasets. Statistical analyses help reveal potential associations between MPs and environmental variables, whereas machine learning methods can autonomously learn relationships between MP characteristics and potential sources. Additionally, the combination of MP diversity indices and environmental source indices with modeling framework has further enhanced model performance. However, the accuracy and applicability of these models require further enhancement. Establishing a global MP database, incorporating more MP characterization indicators and sample data are essential for improving model performance. Future research should also focus on developing an integrated tracking methodology for MP whole life cycle management, strengthening the connection with regulatory governance. Through a critical evaluation and comparison of current MP traceability models, this work provides a basic reference for selecting and applying traceability frameworks, ultimately facilitating precise source tracking and supporting effective policy-making for MP pollution management.

Graphical Abstract

The objective of the research was to investigate the processes of adsorption-cum-photocatalytic degradation aiming at removal of textile dye pollutants like Methylene Blue and Safranin Orange and their mixtures when exposed to UV-A irradiation within a batch photoreactor, following a dark phase adsorption–desorption equilibration. A photocatalytic hybrid membrane was meticulously fabricated by applying the non-solvent induced phase separation technique and thoroughly characterized through techniques like FTIR, TGA, UTM and FESEM. The dimensional stability of the polymer supported composite membrane demonstrated remarkable improvement as compared to the bare copolymer. The fabricated membrane was found to exhibit excellent adsorptive properties with 64.75% removal for 15 mgL⁻¹ methylene blue (MB) dye, and 56.09% for 15 mgL⁻¹ safranin O (SO) dye and photocatalytic properties with 90.08% for 15 mgL⁻¹ MB, and 74.31% for 15 mgL⁻¹ SO, singularly. While, the percentages of photocatalytic degradation of MB (15 mgL⁻¹) and SO (15 mgL⁻¹) in the binary mixture system (MBSO) were found to be 80.38% and 70.28% respectively, when subjected to 120 min of UV-A irradiations. The experimental findings revealed that the most effective photodegradation of both the dyes emerged under UVA irradiation introduced at highly basic pH domains (pH ~ 11) reaching as high as 95.23% for 15 mgL⁻¹ MB and 82.32% for 15 mgL⁻¹ SO solutions respectively. The reusability studies conducted with the membrane exhibited a photodegradation of 80.20% of 15 mgL⁻¹ MB and 62.08% of 15 mgL⁻¹ SO at the end of the fifth cycle. The batch kinetic study showed that the adsorption process followed pseudo-second order and the photocatalysis study followed pseudo-first order.