FA contains complex aromatic and oxygen-containing functional groups, making it chemically stable and difficult to degrade. Although photocatalysis can generate reactive oxygen species under light irradiation, its efficiency is often limited by poor visible-light utilization and rapid charge recombination.
FA, a major humic-substance fraction, forms from long-term transformation of plant residues and microbial metabolites and is widespread in soils, sediments, and surface waters. Its heterogeneous macromolecules contain aromatic moieties, carboxyls, and phenolic hydroxyls that complex metals and co-contaminants, altering their mobility and bioavailability. In drinking-water treatment, FA is troublesome because chlorination can convert it into disinfection by-products such as trihalomethanes and haloacetic acids, raising health concerns and hindering purification. Although photocatalysis generates electron–hole pairs and reactive oxygen species, limited visible-light absorption and fast charge recombination restrict FA removal. Coupling photocatalysis with persulfate AOPs (e.g., PMS) can add oxidants to accelerate degradation and improve mineralization of organics.
A study (DOI:10.48130/aee-0025-0014) published in Agricultural Ecology and Environment on 20 January 2026 by Guangshan Zhang & Chunyan Yang’s team, Qingdao Agricultural University, offers a promising strategy to enhance radical generation and achieve faster, deeper FA degradation in water treatment systems.
Using integrated structural and catalytic diagnostics, the researchers first characterized the BiOCl/MXene photocatalyst by SEM/EDS mapping, TEM/HRTEM, XRD, N₂ adsorption–desorption (BET), and XPS to elucidate morphology, crystallinity, surface area, and interfacial electron transfer. They then evaluated visible-light/PMS performance through synthesis optimization (hydrothermal temperature/time and MXene loading), comparative degradation experiments, kinetic modeling, quantum-yield estimation, and robustness tests across catalyst dosage, FA concentration, pH, coexisting anions, water matrices, recycling cycles, and pollutant types. Photoelectrochemical analyses (UV–vis, PL, EIS, TRPL, Mott–Schottky, photocurrent), radical quenching, and EPR identified charge-transfer behavior and active species, while SUVA, 3D-EEM fluorescence, and TOC tracked structural breakdown and mineralization. SEM and TEM confirmed that BiOCl nanosheets were uniformly anchored on layered MXene with tight interfacial contact, and EDS showed homogeneous Bi/O/Ti/C/Cl distribution. HRTEM resolved BiOCl (101)/(110) and MXene (002) planes, while XRD verified phase coexistence. BET revealed mesoporosity (2–10 nm) and a marked surface-area increase to 41.73 m² g⁻¹ (vs 9.17 m² g⁻¹ for BiOCl), indicating more active sites and improved mass transfer. XPS peak shifts and Bi–O–C bond formation evidenced electron transfer and Schottky-junction construction, promoting carrier separation. Under visible light with PMS, the optimized composite (160 °C, 10 h, 15% MXene) achieved 98.43% FA removal in 30 min, with k = 0.1388 min⁻¹ (3.27× BiOCl) and a synergy factor of 5.28; the apparent quantum yield was ~1.33%, reflecting PMS-assisted electron trapping. High efficiency persisted across pH 3–9 and FA 20–100 mg L⁻¹, with optimal performance at 0.8 g L⁻¹ catalyst and ~2 mM PMS. The catalyst retained >80% activity after five cycles, removed >70% FA in lake water, and effectively degraded antibiotics, dyes, and phenols. Photoelectrochemical data confirmed enhanced visible absorption and faster charge transfer, quenching/EPR identified h⁺ and O₂•⁻ as dominant oxidants, and spectroscopic plus TOC analyses showed rapid chromophore destruction but partial mineralization (49.95%).
FA control is crucial for reducing DBP formation potential before chlorination and improving overall drinking-water safety. This work suggests a practical route: a recyclable visible-light catalyst that activates PMS efficiently, tolerates varied pH and ionic conditions, and performs in complex waters. Beyond FA, the system showed broad activity against different pollutant classes (e.g., antibiotics, dyes, phenols), implying potential use as a flexible AOP platform for mixed-contaminant waters.
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References
DOI
10.48130/aee-0025-0014
Original Souce URL
https://doi.org/10.48130/aee-0025-0014
Funding information
The work was supported by the National Natural Science Foundation of China (Grant Nos 52370174, 52500009), Natural Science Foundation of Shandong Province, China (Grant No. ZR2022ME128), and Harbin Institute of Technology (Weihai) Qingdao Research Institute (Grant No. IQTA10100026).
About Agricultural Ecology and Environment
Agricultural Ecology and Environment (e-ISSN 3070-0639) is a multidisciplinary platform for communicating advances in fundamental and applied research on the agroecological environment, focusing on the interactions between agroecosystems and the environment. It is dedicated to advancing the understanding of the complex interactions between agricultural practices and ecological systems. The journal aims to provide a comprehensive and cutting-edge forum for researchers, practitioners, policymakers, and stakeholders from diverse fields such as agronomy, ecology, environmental science, soil science, and sustainable development.