Mechanism and pathways of chlorfenapyr photocatalytic degradation in aqueous suspension of TiO2.
Mechanism and pathways of chlorfenapyr photocatalytic degradation in aqueous suspension of TiO2.
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DOI：
10.1021/es052073u
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发表时间：
2006-04
影响因子：
11.4
通讯作者：
Yongsong Cao;Lei Yi;Lu Huang;Ying Hou;Yitong Lu
中科院分区：
文献类型：
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作者：
Yongsong Cao;Lei Yi;Lu Huang;Ying Hou;Yitong Lu
在含有 TiO2 作为光催化剂的水溶液中研究了氯芬那吡在紫外线下的光诱导降解。虫螨腈的光催化降解遵循准一级降解动力学 (Ct = C0e(-kt))。该研究的重点是使用气相色谱质谱 (GC-MS) 和 1HNMR 鉴定降解过程中可能的中间产物。处理过程中通过多种技术鉴定出六种芳香族中间体，其中一些通过匹配真实标准进一步得到证实。降解产物的结构分析表明有两条降解途径：（1）氯芬那吡的脂肪族醚基团裂解形成吡咯-α-羧酸，然后吡咯基团断裂形成4-氯甘氨酸； (2)虫螨腈脱溴，脂肪族醚基从吡咯基上断裂，进一步断裂，形成4-氯苯基甘氨酸。甘氨酸被降解为4-氯苯甲酸，4-氯苯甲酸进一步分解为无机离子和CO2。
The light-induced degradation of chlorfenapyr under UV was investigated in aqueous solutions containing TiO2 as photocatalyst. The photocatalytic degradation of chlorfenapyr followed pseudo-first-order degradation kinetics (Ct = C0e(-kt)). The study focused on the identification of possible intermediate products during the degradation, using gas chromatography mass-spectrometry (GC-MS) and 1HNMR. Six aromatic intermediates were identified by several techniques during the treatment and some of them were further confirmed by matching authentic standards. Structure analysis of the degradation products suggested two degradation pathways: (1) The aliphatic ether group was cleaved from chlorfenapyr to form pyrrole-alph-carboxylic acid, then the pyrrole group was broken to form 4-chloroglycine; (2) Chlorfenapyr was debrominated and the aliphatic ether group was cleaved from the pyrrole group, which was further broken to form 4-chlorophenylglycine. The glycine was degraded into 4-chlorobenzoic acids, which was further broken into inorganic ions and CO2.