摘要
采用二氧化铅电极对酸性红G溶液进行电催化降解,主要研究酸性红G的紫外-可见谱变化及其可能降解机制,考察不同因素对降解效果的影响。结果表明,酸性红G在电极表面是以间接氧化机制被羟基自由基氧化。电解过程中,偶氮键断键速率显著高于苯环及萘环,酸性红G去除率显著高于TOC去除率。电解时间延长有利于有机物去除,但会提高能耗值,且单位TOC去除能耗远高于单位酸性红G去除能耗。电流密度提高会促进酸性红G降解与TOC去除,却使单位能耗显著增加,且高电流密度会导致矿化电流效率下降。染料浓度增加使得酸性红G与TOC去除效率降低,但单位能耗随之降低,表明高有机物浓度有利于降低单位能耗值。温度升高有利于有机物降解去除。
In this research,a PbO_2 electrode was adopted as the anode for the electrocatalytic oxidative degradation of acid red G（ ARG）. The main purpose was to study the variations in the ultraviolet-visible spectrum and degradation mechanisms of ARG on the PbO_2 anode. Influences of different factors on the degradation and energy consumption were considered. The results indicated that ARG was oxidized by hydroxyl radicals produced on the electrode surface through indirect oxidation mechanisms. The breaking rate of azo bonds was conspicuously higher than those of benzene rings and naphthalene rings. The ARG removal rate was clearly higher than the total organic carbon（ TOC） removal rate. Although prolonging electrolytic time gave rise to the removal of organics,the energy consumption increased and the unit energy consumption of TOC removal was significantly higher than that of ARG. The increase in current densities promoted ARG degradation and TOC removal,but could also lead to the apparent increase in the unit energy consumption and the decrease in the mineralization current efficiency. The removal efficiencies of ARG and TOC could be reduced by increasing the dye concentration,but the unit energy consumption decreased accordingly,which indicated that a high concentration of organics led to the decrease in the unit energy consumption in electrocatalytic reactions. The temperature increase favored the degradation and removal of organics.
作者
徐浩
郭午琪
张林
周远涛
冯江涛
延卫
XU Hao GUO Wuqi ZHANG Lin ZHOU Yuantao FENG Jiangtao ＊ YAN Wei(Department of Environmental Science and Engineering, Xi＇an Jiaotong University, Xi＇an 710049, China Xi＇ an Capital Water Company Limited, Xi＇ an 710086, China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2016年第11期6479-6485,共7页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(21307098)
中国博士后科学基金资助项目(2013M532053)
关键词
二氧化铅
酸性红G
电催化
羟基自由基
能耗
lead dioxide
Acid Red G
electro-catalysis
hydroxyl radical
energy consumption
