| 均相Co/PMS系统降解吡虫啉的影响因素及降解途径研究 |
| 摘要点击 4962 全文点击 2221 投稿时间：2007-01-12 修订日期：2007-03-07 |
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| 中文关键词 高级氧化技术(AOTs) 硫酸自由基 无机离子 降解机理 废水处理 吡虫啉 |
| 英文关键词 advanced oxidation technologies (AOTs) sulfate radical inorganic ion degradation mechanism wastewater treatment Imidacloprid |
| DOI 10.13227/j.hjkx.20071226 |
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| 中文摘要 |
| 过渡态Co2+-催化分解KHSO5(Co/PMS)系统是一种新型的高级氧化技术，其反应体系可以产生强氧化性的硫酸自由基(SO·-4).以杀虫剂吡虫啉为目标污染物，重点研究了溶液中PMS浓度、Co2+-浓度和无机阴离子(H2PO-4、HCO-3、NO-3和Cl-)对Co/PMS系统降解吡虫啉的影响.结果表明，吡虫啉的降解遵循准一级动力学，其降解速率与氧化剂PMS浓度和催化剂Co2+-的浓度呈正相关.吡虫啉的降解速率随着PMS和Co2+-浓度的增加而增大，但是当PMS与吡虫啉的摩尔比大于20时，增加PMS的浓度对吡虫啉的降解速率反而有一定程度的抑制.H2PO-4能促进Co/PMS系统对虫啉的降解；低浓度的HCO-3促进吡虫啉的降解，高浓度则为抑制作用；Cl-抑制吡虫啉的降解，而NO-3则对整个降解过程影响不明显.研究中采用GC/MS分析吡虫啉降解的中间产物，得到了6-氯烟酸和6-氯烟酰胺2种主要的中间产物，并由此推测其可能的降解途径. |
| 英文摘要 |
| Cobaltous-mediated decomposition of peroxymonosulfate (Co/PMS) system is one of novel advanced oxidation technologies (AOTs), which leads to the formation of very strong oxidizing species in aqueous phase. Effects of PMS concentrations, Co2+- concentrations and various inorganic anions (H2PO-4, HCO-3, NO-3, Cl-) on the degradation of Imidacloprid induced by Co/PMS system was investigated as emphasis. The degradation kinetics of imidacloprid followed pseudo first-order kinetics and reaction rates related to PMS and Co2+- concentrations. The reaction rates increased with increasing ［PMS］ and ［Co2+-］ when the other parameters were constant. However, the decrease of degradation rates was found when the molar ratio of PMS versus imidacloprid was over 20. The effects of H2PO-4 had positive effect on the degradation of Imidacloprid, low concentration HCO-3 had positive effect and high concentration HCO-3 had negative effect, Cl- had negative effect, while NO-3 had little effect. Based on the results of GC/MS, two main intermediates were identified, 6-chloronicotinic acid and 6-chloronicotinamide, and the reaction pathway for SO·-4 induced by homogeneous Co/PMS was proposed accordingly. |
