运用BDD电极优化废水中氨氮的直接电化学检测方法  

Direct electrochemical detection of ammonia in wastewater using boron-doped diamond(BDD)electrode

作　　者：张浩 曾瑜昕 崔骏 裴元生[1] ZHANG Hao;ZENG Yuxin;CUI Jun;PEI Yuansheng(School of Environment,Beijing Normal University,Beijing 100875,China;Chinese Research Academy of Environmental Sciences,Beijing 100012,China)

机构地区：[1]北京师范大学环境学院,北京100875 [2]中国环境科学研究院,北京100012

出　　处：《环境工程学报》2021年第12期4067-4076,共10页Chinese Journal of Environmental Engineering

基　　金：国家水体污染控制与治理科技重大专项(2018ZX07109)。

摘　　要：针对高氨氮条件下离子选择电极稳定性差的问题,筛选了3种市售硼掺杂金刚石(BDD)电极,以探究直接电化学检测氨氮的可行性。采用极化曲线法测试了3种BDD电极的析氧、析氢和析氯电位,以获得最佳电势窗口。采用循环伏安法研究了氨氮在3种BDD电极上的氧化还原行为,在1.6 V处发现了明显的氨氮氧化峰,可为氨氮直接检测提供定性依据。通过控制变量法优化了方波伏安法(SWV)和差分脉冲伏安法两种扫描方式的测试参数。结果表明,SWV响应电流更高。最佳测试参数为:方波频率10 Hz,阶跃电位2 mV,脉冲幅度50 mV。在最佳条件下,当氨氮浓度为1~18 mmol·L^(−1)时,发现两段线性范围,最低检测限为0.283 mmol·L^(−1)。本研究所建立的测试方法响应时间短、线性范围宽、稳定性强,并成功应用于垃圾渗滤液中氨氮的测定。To address the challenges of poor stability of ion-selective electrode under high ammonium condition,three commercial boron-doped diamond(BDD)electrodes were used for the direct electrochemical detection of ammonia-nitrogen to evaluate the feasibility.The best potential window among three BDD electrodes was obtained through measuring the oxygen,hydrogen,and chlorine evolution potentials by the polarization curve method.A clear ammonia-nitrogen oxidation peak was detected at 1.6 V,which could be used as the qualitative basis for direct measurement of ammonia-nitrogen.The parameters of square wave voltammetry(SWV)and differential pulse voltammetry were optimized by the variable control method.The results showed that SWV had a larger response current than DPV and that the optimal parameters of SWV are square wave frequency at 10 Hz,step potential of 2 mV,and pulse amplitude of 50 mV.Two linear ranges were found with the ammonia-nitrogen in the range of 1~18 mmol·L^(−1)under the optimized conditions,and the minimum detection limit was 0.283 mmol^(-1).The advantages of this method included short response time,wide linear range and strong stability.Also,this method has been successfully applied to determine the ammonianitrogen in landfill leachate.

关 键 词：硼掺杂金刚石电极 氨氮 方波伏安法 差分脉冲伏安法 

分 类 号：X832[环境科学与工程—环境工程]