Institute of Plant Protection, Beijing Academy of Agriculture and Forestry Science, Beijing 100097, China; College of Agricultural Sciences, Jiangxi Agricultural University, Nanchang 330045, China.
Institute of Plant Protection, Beijing Academy of Agriculture and Forestry Science, Beijing 100097, China.
Ecotoxicol Environ Saf. 2022 Aug;241:113815. doi: 10.1016/j.ecoenv.2022.113815. Epub 2022 Jun 30.
Imidacloprid (IMI) as a first-generation commercial neonicotinoid has been frequently detected in the environment in recent years. In this study, the efficient degradation of IMI in soil by a thermally activated persulfate (PS) process was investigated. The degradation efficiencies of IMI were in the range of 82-97% with the PS dosage of 10 mM, when the initial concentrations of IMI were 5-50 mg/kg in the soil. Degradation of the IMI was fitted with a pseudo-first-order kinetic model under different reaction temperatures. Inhibition effects of the common inorganic anions on the IMI degradation in the system followed the order Cl > HCO > HPO > NO. Soil pH and soil organic matter were also main factors affecting the degradation of IMI. The degradation efficiencies (64-97%) of three other typical neonicotinoids (acetamiprid, clothianidin, and dinotefuran) indicated that the thermally activated persulfate process could be used for remediation of neonicotinoid-contaminated soil. Quenching experiments indicated that the major reactive species in IMI degradation were SO, O, and •OH. Six degradation intermediates of IMI were inferred in the soil, and degradation pathways of IMI included hydroxylation, denitrification, C-N bond break and further oxidation.
近年来，吡虫啉（IMI）作为第一代商业烟碱类杀虫剂，在环境中频繁被检出。本研究采用热活化过硫酸盐（PS）工艺，考察了其在土壤中对 IMI 的有效降解。当 PS 投加量为 10 mM，IMI 初始浓度为 5-50 mg/kg 时，IMI 的降解效率范围为 82-97%。在不同反应温度下，IMI 的降解符合拟一级动力学模型。在该体系中，常见无机阴离子对 IMI 降解的抑制作用大小顺序为 Cl > HCO > HPO > NO。土壤 pH 值和土壤有机质也是影响 IMI 降解的主要因素。三种典型的新烟碱类杀虫剂（乙酰甲胺磷、噻虫嗪和噻虫啉）的降解效率（64-97%）表明，热活化过硫酸盐工艺可用于修复新烟碱类杀虫剂污染的土壤。猝灭实验表明，IMI 降解的主要活性物质为 SO、O 和 •OH。在土壤中推断出 IMI 的 6 种降解中间产物，IMI 的降解途径包括羟化、脱氮、C-N 键断裂和进一步氧化。
