有机配体对铁电絮凝体系中羟基自由基氧化降解苯胺的影响  

Effects of organic ligands on aniline oxidation and degradation by produced hydroxyl radical in iron electrocoagulation

作　　者：符文晶 魏桃员[1] 谢世伟[1] 张严 FU Wenjing;WEI Taoyuan;XIE Shiwei;ZHANG Yan(School of Urban Construction,Wuhan University of Science and Technology,Wuhan 430065,China)

机构地区：[1]武汉科技大学城市建设学院,武汉430065

出　　处：《环境工程学报》2020年第3期605-614,共10页Chinese Journal of Environmental Engineering

基　　金：国家自然科学基金资助项目(51808415)。

摘　　要：铁电絮凝(Fe-EC)是一种高效的水处理方法,但其中有机污染物的去除机制尚不明晰。为研究有机废水中常见的有机配体对铁电絮凝过程中羟基自由基(·OH)产生以及有机污染物降解的影响,采用了对照实验、淬灭实验和电子自旋共振(ESR)等测试方法。结果表明:草酸(H2C2O4)和乙二胺四乙酸(EDTA)能有效促进铁电絮凝对苯胺(AN)的氧化降解,而·OH是起主要作用的活性氧化物;草酸和EDTA体系中主要存在的Fe(Ⅱ)络合物浓度与羟基自由基产率成正相关关系,1 mol的Fe(Ⅱ)-EDTA2-会产生235 mmol的·OH,是草酸的9倍;EDTA会与污染物竞争羟基自由基。进一步分析可知,在铁电絮凝体系中,EDTA的浓度为0.05 mmol·L^-1时,对苯胺氧化降解的促进效果最佳。以上研究结果可为认识铁电絮凝中污染物的去除机制提供参考。Iron electrocoagulation(Fe-EC)is an effective water treatment method,but the removal mechanism of organic pollutants is still unclear.In order to study the effects of common organic ligands in organic wastewater on the production of hydroxyl radicals(·OH)generation and degradation of organic pollutants were investigated during Fe-EC,control experiments,quenching experiments,and electron spin resonance(ESR)tests were used.Experiment results showed that oxalate(H2C2O4)and ethylenediaminetetraacetic acid(EDTA)could effectively promote the oxidative degradation of aniline,and hydroxyl radical the main oxidant in Fe-EC.The production of hydroxyl radical was positively correlated to the concentrations of Fe(Ⅱ)ligands in oxalate and EDTA systems.The production of hydroxyl radicals was estimated to be 235 mmol by per molar of EDTA,which was 9 times more than that of oxalate.However,EDTA competes with pollutants for hydroxyl radicals.The optimal concentration of EDTA was 0.05 mmol·L^-1 for promoting the oxidative degradation of aniline in the Fe-EC system.The above research results can provide a reference for understanding the mechanism of pollutant removal during Fe-EC.

关 键 词：铁电絮凝 草酸 EDTA 羟基自由基 苯胺降解 

分 类 号：X523[环境科学与工程—环境工程]