钛基修饰电极催化电解去除水中硝酸盐氮的研究  

Catalytic electrolysis removal of nitrate in water by modified Ti substrate electrodes.

作　　者：叶舒帆[1] 胡筱敏[1] 董俊[1] 张杨[2] 和英滇[1] 

机构地区：[1]东北大学资源与土木工程学院,辽宁沈阳110004 [2]东北大学信息科学与工程学院,辽宁沈阳110004

出　　处：《中国环境科学》2011年第1期44-49,共6页China Environmental Science

基　　金：国家科技重大专项课题(20092X07526-006)

摘　　要：利用热分解法制备CuO修饰Ti基阴极和SnO2-Sb2O5修饰Ti基阳极,组成无隔膜电解体系,以模拟废水(NO3--N 50mg/L)为对象,进行了水中NO3--N去除实验研究.结果数据表明,CuO修饰Ti基阴极对水中NO3--N的去除率随电流密度、极板间距、搅拌强度和电解时间增加而增加,在电流密度10mA/cm2、极板间距9mm、中等搅拌强度下电解150min,NO3--N催化还原去除率可达93.8%.Cl-支持电解可使NO3--N催化还原产物NH4+-N氧化为N2-N去除.在电流密度10mA/cm2、极板间距9mm、NaCl添加量600mg/L、中等搅拌强度下电解120min后,NO3--N和TN的去除率达到89.3%和86.9%,NO2--N和NH4+-N未检出.分析认为NO3--N还原机制为NOx中O被阴极表面Cu吸附固定,N—O键受氢攻击破坏,逐步还原.阳极电解Cl-生成HOCl,HOCl氧化NH4+-N成N2-N.A comprehensive experimental study was conducted to investigate a new method of NO3——N removal in a septum-free electrolysis system based on simulated wastewater,i.e.50mg/L NO3——N.CuO modified-Ti and SnO2-Sb2O5 modified-Ti were prepared via pyrolyticprocess and adopted as cathode and anode,respectively.CuO modified-Ti cathode could work as catalyst to reduce NO3——N and the resulting rate of removal increased with the increasing in current density,space between electrodes,stirring intensity and reaction time.A high rate of removal（93.8%） was obtained when applying current density at 10mA/cm2,space between electrodes at 9mm,stirring intensity at middle-scale for 150 min.In addition,NH4＋-N which was the reduction product of NO3——N could be oxidized to N2-N under the support electrolysis of Cl-.With a starting NaCl concentration at 600mg/L,current density at 10mA/cm2,space between electrodes at 9mm,stirring intensity at middle-scale for 120 min,the removal rate of NO3——N and TN is 89.3% and 86.9%,respectively,and no NO2——N or NH4＋-N were detected.The NO3——N reducing mechanism may be O in NOx fixed by Cu adsorbing,then gradual reduced via reductant attacking N—O.In addition,NH4＋-N oxidized to N2 due to the HOCl generation from anode electrolysis of Cl-.

关 键 词：硝酸盐氮 修饰电极 催化还原 氨氮 氯氧化 

分 类 号：X703.1[环境科学与工程—环境工程]