Lei Qin

Lead (Pb) accumulation in paddy soils promotes its transfer to rice grains, posing persistent risks to food safety and human health. Here, we developed a GSNO-encapsulated chitosan–biochar-supported sulfidized nanoscale zero-valent iron composite (GSNO-CS@S-nZVI/BC) to integrate sustained nitric oxide (NO) delivery with Pb immobilization in rice–soil systems. The novelty of this strategy lies in coupling a biocompatible NO donor with a Pb-reactive CS@S-nZVI/BC matrix to simultaneously alleviate Pb-induced physiological stress in rice and suppress Pb migration from soil to edible grains. In hydroponic experiments, Pb exposure reduced rice fresh weight, dry weight, and chlorophyll levels by 71.2%, 55.6%, and 75.1%, respectively. Compared with Pb treatment alone, GSNO-CS@S-nZVI/BC increased rice dry weight and chlorophyll levels by 68.5% and 260%, respectively, while decreasing Pb concentrations in roots and shoots by 78.2% and 85.8%. In soil pot experiments, GSNO-CS@S-nZVI/BC reduced Pb concentrations in roots, shoots, panicles, and grains by 57.6%, 57.0%, 40.3%, and 64.3%, respectively. It also decreased the grain Pb bioconcentration factor by 80.7%, reduced the soil-to-root Pb translocation factor by 84.41%, and lowered the grain Pb bioconcentration factor to 0.043 ± 0.007. Mechanistically, GSNO-CS@S-nZVI/BC promoted root iron plaque formation by 176.1% and increased Pb adsorption by root iron plaque by 156.9%, while decreasing the oxidizable Pb fraction in soil by 11% and increasing the reducible Pb fraction by 10%. These results indicate that GSNO-CS@S-nZVI/BC mitigates Pb toxicity through sustained NO release, enhanced root iron plaque-mediated Pb sequestration, and soil Pb stabilization. Overall, this nano-enabled amendment provides a promising strategy for reducing Pb transfer from contaminated paddy soils to rice grains and improving the safe utilization of Pb-contaminated farmland.

Microplastics (MPs) are persistent contaminants widely distributed across aquatic, terrestrial, and atmospheric environments. Previous reviews have shown that MPs can carry pollutants and change their environmental behavior, but the field is now broad enough that a simple repetition of sources, adsorption mechanisms, and toxicity would add limited value. This review therefore organizes MPs–pollutant–interactions as a connected chain from sources and environmental pathways to interaction mechanisms, biological effects, and management actions. It summarizes the major MPs input pathways and representative polymer types across water, soil, and air, and then explains how partitioning, surface adsorption, desorption, and pore filling control the binding and release of pollutants. The review further discusses how MPs properties, pollutant characteristics, pollutant mixtures, biofilms/plastisphere, and environmental factors jointly regulate these processes. In addition, it evaluates the consequences of MPs-pollutant coupling for pollutant mobility, bioavailability, biodegradation, bioaccumulation, trophic transfer, ecological toxicity, and human exposure. Finally, the review links these processes with practical management needs, including wastewater treatment, sludge reuse, agricultural plastic control, atmospheric monitoring, environmental education, and long-term risk assessment. By bringing these topics into one framework, this review provides a clearer basis for understanding and managing MPs-associated mixed pollution in environmental systems.

The photothermal process has attracted considerable attention in water treatment due to its advantages of low energy consumption and high efficiency. In this respect, photothermal materials play a crucial role in the photothermal process. Particularly, carbonaceous materials have emerged as promising candidates for this process because of exceptional photothermal performance. While previous research on carbonaceous materials has primarily focused on photothermal evaporation and sterilization, there is now a growing interest in exploring the potential of photothermal effect‐assisted advanced oxidation processes (AOPs). However, the underlying mechanism of the photothermal effect assisted by carbonaceous materials remains unclear. This review aims to provide a comprehensive review of the photothermal process of carbonaceous materials in water treatment. It begins by introducing the photothermal properties of carbonaceous materials, followed by a discussion on strategies for enhancing these properties. Then, the application of carbonaceous materials‐based photothermal process for water treatment is summarized. This includes both direct photothermal processes such as photothermal evaporation and sterilization, as well as indirect photothermal processes that assisted AOPs. Meanwhile, various mechanisms assisted by the photothermal effect are summarized. Finally, the challenges and opportunities of using carbonaceous materials‐based photothermal processes for water treatment are proposed.

Over the last decades, advanced oxidation processes (AOPs) have been widely used in surface and ground water pollution control. The heterogeneous electro-Fenton (EF) process has gained much attention due to its properties of high catalytic performance, no generation of iron sludge, and good recyclability of catalyst. As of October 2022, the cited papers and publications of EF are around 1.3 × 10⁻⁵ and 3.4 × 10⁻³ in web of science. Among the AOP techniques, the contaminant removal efficiencies by EF process are above 90% in most studies. Current reviews mainly focused on the mechanism of EF and few reviews comprehensively summarized heterogeneous catalysts and their applications in wastewater treatment. Thus, this review focuses on the current studies covering the period 2012–2022, and applications of heterogeneous catalysts in EF process. Two kinds of typical heterogeneous EF systems (the addition of solid catalysts and the functionalized cathode catalysts) and their applications for organic contaminants degradation in water are reviewed. In detail, solid catalysts, including iron minerals, iron oxide-based composites, and iron-free catalysts, are systematically described. Different functionalized cathode materials, containing Fe-based cathodes, carbonaceous-based cathodes, and heteroatom-doped cathodes, are also reviewed. Finally, emphasis and outlook are made on the future prospects and challenges of heterogeneous EF catalyst for wastewater treatments.