• 关键词：感应电芬顿  二甲基砷  催化  降解

• 基金项目：国家自然科学基金（No.51478455，51378490）

• 吕杰婵
• 1. 河北工业大学土木与交通工程学院, 天津 300400;2. 中国科学院生态环境研究中心, 中国科学院饮用水科学与技术重点实验室, 北京 100085

• 窦远明
• 河北工业大学土木与交通工程学院, 天津 300400

• 孙猛
• 中国科学院生态环境研究中心, 中国科学院饮用水科学与技术重点实验室, 北京 100085

• 晋超
• 中国科学院生态环境研究中心, 中国科学院饮用水科学与技术重点实验室, 北京 100085

• 兰华春
• 中国科学院生态环境研究中心, 中国科学院饮用水科学与技术重点实验室, 北京 100085

• 摘要：二甲基砷作为甲基砷的主要种类之一，主要由含砷废水的排放和农药滥用进入环境水体，进而严重威胁着人类的健康.通过改进电芬顿反应中Fe²⁺的投加方式，构建了以铁棒为感应阳极、RuO₂/Ti网为阳极、2个活性炭纤维为双阴极的感应电芬顿体系.为探究感应电芬顿体系对二甲基砷的降解效果与机理，考察了反应过程中初始pH、电流密度、反应物初始浓度等因素对二甲基砷去除效果的影响.结果表明，在初始pH值为3，电流密度为2 mA·cm^-2，二甲基砷初始浓度为5 mg·L^-1的最佳条件下，经感应电芬顿反应240 min后，二甲基砷去除率高达94.4%.在此体系中，感应铁电极不断释放的Fe²⁺与阴极产生的H₂O₂发生电芬顿反应产生羟基自由基将二甲基砷降解为一甲基砷、As（III）和As（V），同时，铁离子水解生成的铁的羟基络合物将二甲基砷、一甲基砷、As（III）和As（V）吸附在其表面，从而达到二甲基砷的高效去除.

• Abstract：Aqueous dimethyl arsenic (DMA) contaminant, mainly resulted from the drainages of arsenic-and pesticide-containing wastewater, severely threat the health of human being. Herein, a modified Fenton-process was designed for the high removal efficiency, in which the Fe stick as an induced electrode was between the RuO₂/Ti anode and activated carbon fibers cathode. In addition, a different Fe²⁺ dosage pathway was also applied in the modified Fenton system. In order to investigate the degradation efficiency and the degradation mechanism, some pertinent parameters, including the initial concentration of DMA, pH, current density, were studied in detail. After 240 min, 94.4% of DMA can be thoroughly removed at the optimal condition(pH=3, current density of 2 mA·cm^-2, and the initial concentration of 5 mg·L^-1). Furthermore, some intermediates such as monmethyl arsenic, arsenate oxide were observed by the Fenton reaction between the induced Fe²⁺ with the H₂O₂. In this process, the as-formed intermediates were further adsorbed by Fenton reaction products (fresh Fe(OH)_x) via the strong complexation effect.

• Key words：field-induced electro-Fenton  dimethyl arsenic  catalysis  degradation

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