Propyrisulfuron is a novel sulfonylurea herbicide used for controlling annual grass and broad-leaved weeds in fields, but its fates and behaviors in environment are still unknown, which are of utmost importance for environmental protection. To reduce its potential environmental risks in agricultural production, the hydrolysis kinetics, influence of 34 environmental factors including 12 microplastics (MPs), disposable face masks (DFMs) and its different parts, 6 fertilizers, 5 ions, 3 surfactants, a co-existed herbicide of florpyrauxifen-benzy, humic acid and biochar, and the effect of MPs and DFMs on its hydrolysis mechanisms were systematically investigated. The main hydrolysis products (HPs), possible mechanisms, toxicities and potential risks to aquatic organisms were studied. Propyrisulfuron hydrolysis was an acid catalytic pyrolysis, endothermic and spontaneous process driven by the reduction of activation enthalpy, and followed the first-order kinetics. All environmental factors can accelerate propyrisulfuron hydrolysis to varying degrees except humic acid, and different hydrolysis mechanisms occurred in the presence of MPs and DFMs. In addition, 10 possible HPs and 7 possible mechanisms were identified and proposed. ECOSAR prediction and ecotoxicity testing showed that acute toxicity of propyrisulfuron and its HPs for aquatic organisms were low, but may have high chronic toxicity and pose a potential threat to aquatic ecosystems. The investigations are significantly important for elucidating the environmental fates and behaviors of propyrisulfuron, assessing the risks in environmental protection, and further providing guidance for scientific application in agro-ecosystem.

丙吡磺隆是一种新型磺酰脲类除草剂，用于防治田间一年生禾本科杂草和阔叶杂草，但其在环境中的归宿和行为仍不清楚，这对于环境保护至关重要。为了降低其在农业生产中潜在的环境风险，水解动力学、34种环境因素的影响，包括12种微塑料（MPs）、一次性口罩（DFMs）及其不同部件、6种肥料、5种离子、3种表面活性剂、共存的系统研究了除草剂氟吡草芬、腐植酸和生物炭的水解机理，以及MPs和DFMs对其水解机制的影响。研究了主要水解产物（HP）、可能的机制、毒性和对水生生物的潜在风险。丙吡磺隆水解是由活化焓降低驱动的酸催化热解、吸热、自发过程，遵循一级动力学。除腐殖酸外，所有环境因素均能不同程度地加速丙吡磺隆的水解，并且在 MPs 和 DFMs 存在下发生不同的水解机制。此外，还确定并提出了 10 个可能的 HP 和 7 个可能的机制。ECOSAR预测和生态毒性测试表明，丙吡磺隆及其HPs对水生生物的急性毒性较低，但可能具有较高的慢性毒性，对水生生态系统构成潜在威胁。该研究对于阐明丙嘧磺隆的环境归趋和行为、评估环境保护风险、进一步为农业生态系统的科学应用提供指导具有重要意义。