铁电絮凝产羟自由基氧化降解地下水中磺胺

为了揭示铁电絮凝(EC)过程中尚未被认识的羟自由基氧化机制，以磺胺污染的地下水为对象进行电絮凝降解研究。通过淬灭自由基、厌氧电絮凝和加Fe(III)盐等对照实验，探究反应体系是否存在羟自由基氧化机制；并对不同电解质、溶液pH、初始磺胺浓度、电流强度条件下的电絮凝降解磺胺效率进行了测定。研究结果表明：铁电絮凝处理磺胺废水反应体系存在羟自由基氧化降解磺胺机制；地下水中，阴离子对铁电絮凝氧化效果的影响较小。对模拟江汉平原含0.2 mg·L-1 As(III)和0.1 mg·L-1磺胺的地下水进行铁电絮凝处理，在30 mA的电流条件下，As(III)在4 h内的去除率达到100%，而磺胺达到68.6%。

Hydroxyl radical induced by iron electrocoagulation for oxidative degradation of sulfonamide in groundwater

In order to reveal the possible hydroxyl radical oxidation mechanism during iron electrocoagulation(EC), we investigated the degradation of sulfonamide in contaminated groundwater. Whether the hydroxyl radical oxidation mechanism for sulfonamide degradation existed or not in EC system was explored through the control experiments of radical quenching, anaerobic EC and Fe(III) salt addition. The sulfonamide degradation efficiencies by EC under different electrolytes, solution pH, initial concentration of sulfonamide and current intensity were tested. The results showed that the hydroxyl radical oxidation mechanism of sulfonamide degradation occurred during EC process; in groundwater, anions had slight influence on sulfonamide oxidation by EC. Furthermore, EC was used to treat the simulated groundwater in Jianghan plain with 0.2 mg·L-1 As(III) and 0.1 mg·L-1 sulfonamide, it could remove 100% As(III) and 68.6% sulfonamide after 4 h treatment at the current of 30 mA.