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.
作者
张浩
曾瑜昕
崔骏
裴元生
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)
出处
《环境工程学报》
CAS
CSCD
北大核心
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)。
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
boron-doped diamond electrode
ammonia-nitrogen
square wave voltammetry
differential pulse voltammetry
