农药吡虫啉和噻虫嗪的电子束辐照降解效果及机理分析
Degradation Effect and Mechanism Analysis of Pesticides Imidacloprid and Thiamethoxam by Electron Beam Irradiation
魏强林 1杨波 2张建波 3聂晨 3刘军涛 4刘义保 1刘志毅4
作者信息
- 1. 东华理工大学核技术应用教育部工程研究中心,江西南昌 330013;东华理工大学核科学与工程学院,江西南昌 330013;东华理工大学核物理与核技术江西省重点实验室,江西南昌 330013
- 2. 东华理工大学核科学与工程学院,江西南昌 330013;东华理工大学核物理与核技术江西省重点实验室,江西南昌 330013
- 3. 东华理工大学核科学与工程学院,江西南昌 330013
- 4. 兰州大学核科学与技术学院,甘肃兰州 730000;兰州大学稀有同位素前沿科学中心,甘肃兰州 730000
- 折叠
摘要
为深入分析农药辐照降解机理,采用电子束辐照降解技术研究典型新烟碱类农药吡虫啉和噻虫嗪在1～5 kGy吸收剂量下的辐照降解效果及影响因素,并分析了农药降解途径及其机理.结果显示,电子束辐照能有效降解吡虫啉和噻虫嗪,降解率与吸收剂量呈正相关、与农药的初始质量浓度呈负相关,中性酸碱度和低浓度双氧水对农药降解有促进作用.吡虫啉和噻虫嗪依靠辐解产生的对农药降解有促进作用的·OH自由基、·H自由基和水合电子eaq-作用于N-硝基亚氨基咪唑烷结构、四氢嗯二嗪结构使其降解,最终产物分别为6-氯烟酸、2-氯噻唑-5-甲胺.
Abstract
In order to further analyze the mechanism of pesticide irradiation degradation,the irradiation degrada-tion effects and influencing factors of typical neonicotinoid pesticides imidacloprid and thiamethoxam from 1 kGy to 5 kGy absorbed dose were studied by electron beam irradiation degradation technology,and the degradation path-way and mechanism of pesticides were analyzed.The results showed that the degradation rate of imidacloprid and thiamethoxam could be effectively degraded by electron beam irradiation.The degradation rate was positively cor-related with the absorbed dose and negatively correlated with the initial mass concentration of pesticides.The neu-tral solution and low hydrogen peroxide concentration could promote the degradation of pesticides.Through the analysis of irradiation products and their degradation pathways,it was found that imidacloprid and thiamethoxam mainly rely on·OH radical,·H radical and hydrated electron eaq-to degrade n-nitroimidazolidane structure and tetrahydrooxadiazine structure.These free radicals and hydrated electrons are produced by irradiation and can promote the degradation of pesticides.The final degradation products of imidacloprid and thiamethoxam were 6-chloronicotinic acid and 2-chlorothiazole-5-methylamine,respectively.
关键词
电子束辐照/新烟碱类农药/降解产物/降解效果/降解机理Key words
electron beam irradiation/neonicotinoid pesticides/degradation products/degradation effect/degra-dation mechanism引用本文复制引用
出版年
2024
NETL
NSTL
万方数据