中文关键词土壤纳米零价铁(nZVI)过氧化钙α-HCH淋洗类芬顿 英文关键词soilnanoscale zero-valent iron (nZVI)CaO₂α-HCHleachingFenton-like

作者	单位	E-mail
姚静波	常州大学环境与安全工程学院, 常州 213164	2440185504@qq.com
周杰	常州大学环境与安全工程学院, 常州 213164
王明新	常州大学环境与安全工程学院, 常州 213164	wmxcau@163.com
荀志祥	常州大学环境与安全工程学院, 常州 213164
薛金娟	常州大学环境与安全工程学院, 常州 213164

中文摘要 采用纳米零价铁（nZVI）和过氧化钙（CaO₂）组成非均相类芬顿试剂降解土壤淋洗废液中的α-HCH，研究其降解效能及机制.结果表明，nZVI/CaO₂可在较广的pH范围内有效降解α-HCH，当nZVI和CaO₂的投加量为1g·L^-1，pH值为5时降解率可达93.23%.nZVI和CaO₂单独或联合处理α-HCH过程均呈准一级反应动力学模式，联合处理的反应速率常数大于单独处理之和，表明两者联合降解α-HCH具有较好的协同作用.自由基淬灭实验发现，超氧自由基对降解α-HCH的贡献率远大于羟基自由基.nZVI/CaO₂降解α-HCH的中间产物主要是三氯苯和氯苯，其中三氯苯呈先急剧上升后迅速降解趋势，氯苯含量较低且变化较小，因此推测α-HCH主要降解途径是先还原为三氯苯，再继续还原为氯苯或矿化为二氧化碳和水. 英文摘要 Nano zerovalent iron (nZVI) and CaO₂ were used to construct a heterogeneous Fenton-like system to degrade α-hexachlorocyclohexane (α-HCH) in soil solution, and the degradation efficiency and mechanism were investigated. The results showed that nZVI/CaO₂ can degrade α-HCH in an extensive pH range. When the dosage of nZVI and CaO₂ was 1 g·L^-1 and pH was 5, the degradation rate of α-HCH reached 93.23%. The degradation process of nZVI, CaO₂, and nZVI/CaO₂ treatments accorded with the first-order reaction kinetics model. The reaction rate constant of nZVI/CaO₂ was greater than the sum of individual treatments, showing that nZVI/CaO₂ has a synergistic effect on the degradation of α-HCH. Through quenching free radical experiments, the contribution rate of superoxide radicals was shown to be greater than that of hydroxyl radicals. Intermediates, including trichlorobenzene and chlorobenzene, were detected. The content of trichlorobenzene showed a sharp increase initially, and then decreased quickly. The chlorobenzene content was low and showed little change. The α-HCH in the soil washing solution was first reduced to trichlorobenzene, which was further reduced to chlorobenzene or mineralized into CO₂ and water directly.

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