研究了电化学法去除废水中低浓度氨氮的效果和氨氮的氧化机制。考察了氯离子浓度、电流密度和pH等操作参数对氨氮氧化效果的影响。结果表明,电化学法对低浓度氨氮的去除主要通过电解过程中阳极产生的次氯酸根和羟基自由基的间接氧化作用。在氯离子质量浓度为400 mg/L、电流密度为20 mA/cm²和不调节原水pH的条件下,电解150 min后氨氮质量浓度由100 mg/L降至1.7 mg/L,去除率达98.1%,无副产物亚硝酸盐氮(NO^-₂-N)产生,最终副产物硝酸盐氮(NO^-₃-N)质量浓度为1.9 mg/L,氮气选择性约为97%。

The effect of electrochemical removal of low concentration ammoniacal nitrogen in wastewater and the oxidation mechanism of ammoniacal nitrogen are studied.The influences of chloride ion concentration,current density and pH on oxidation effect of ammoniacal nitrogen are analyzed.It is found that the removal of low concentration ammoniacal nitrogen by electrochemical method mainly depends on the indirect oxidation of hypochlorite and hydroxyl radicals generated by the anode during the electrolysis process.The concentration of ammoniacal nitrogen decreases from 100 mg·L^-1 to 1.7 mg·L^-1 after 150 min of electrolysis under the conditions that chloride ion concentration is 400 mg·L^-1,current density is 20 mA·cm^-2 and raw water pH is not adjusted.The removal rate reaches 98.1%,no by-product nitrites (NO₂-N) is produced,and the final by-product nitrates-based nitrogen (NO^-₃-N) concentration is 1.9 mg·L^-1,and the selectivity of nitrogen gas is about 97%.

唐良栋(1998-),男,硕士生,研究方向为水污染控制新技术,1499204229@qq.com;赵贤广(1968-),男,博士,教授,研究方向为工业污染控制新技术研发及工程应用,通讯联系人,zxg174@163.com。