Wang Jianwei, Yue Weifeng, Teng Yanguo, Zhai Yuanzheng, Zhu Hanhua
College of Water Sciences, Beijing Normal University, Beijing, 100875, China; Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China; Engineering Research Center of Groundwater Pollution Control and Remediation Ministry of Education, Ministry of Education of China, Beijing Normal University, China.
College of Water Sciences, Beijing Normal University, Beijing, 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation Ministry of Education, Ministry of Education of China, Beijing Normal University, China.
Chemosphere. 2023 Apr;320:138054. doi: 10.1016/j.chemosphere.2023.138054. Epub 2023 Feb 3.
Methyl parathion (MP) is a typical organophosphorus pesticide that is widely used worldwide, and hydrolysis, oxidation and reduction are the main abiotic degradation processes. Manganese dioxide (MnO) and organic acid can participate in various geochemical processes of pollutants, a reaction system was constructed to degrade MP using δ-MnO and oxalic acid. The δ-MnO/oxalic acid reaction system could efficiently degrade MP, and the removal rate of MP (20 μM) reached 67.83% within 30 h under the optimized conditions (pH 5, [δ-MnO] = 2 mM, [oxalic acid] = 100 mM). MP was hydrolyzed by substitution reactions of S@P and S@C, and reduced by conversion of the nitro groups (-NO) in MP and its hydrolysates to amino groups (-NH). The primary active substance produced in the reaction system was the complexes dominated by Mn(III)-oxalic acid. This study provides a scientific basis for the degradation of organophosphorus pesticides using MnO and an organic acid. The results have important theoretical significance and application value for pollution control and remediation of organophosphorus pesticides.
甲基对硫磷（MP）是一种典型的有机磷农药，在全球范围内广泛使用，水解、氧化和还原是其主要的非生物降解过程。二氧化锰（MnO）和有机酸可参与污染物的各种地球化学过程，构建了一个使用δ-MnO和草酸降解MP的反应体系。δ-MnO/草酸反应体系能有效降解MP，在优化条件（pH 5，[δ-MnO]=2 mM，[草酸]=100 mM）下，30小时内MP（20 μM）的去除率达到67.83%。MP通过S@P和S@C的取代反应发生水解，并通过MP及其水解产物中的硝基（-NO）转化为氨基（-NH）而被还原。反应体系中产生的主要活性物质是以Mn(III)-草酸为主的络合物。本研究为利用MnO和有机酸降解有机磷农药提供了科学依据。研究结果对有机磷农药污染控制与修复具有重要的理论意义和应用价值。
