除氮电解器应用于低电导率清淤尾水的性能研究  

Performance of a denitrifying electrolyzer applied to low-conductivity dredging tailwater

作　　者：邢思奇 易娟 吴旭[1] XING Siqi;YI Juan;WU Xu(School of Environmental Science and Engineering,Huazhong University of Science and Technology,Wuhan 430070,China;Hubei Huadelai Energy Saving and Emission Reduction Technology Co.,Ltd.Wuhan 430200,China)

机构地区：[1]华中科技大学环境科学与工程学院,武汉430070 [2]湖北华德莱节能减排科技有限公司,武汉430200

出　　处：《环境工程学报》2025年第2期333-341,共9页Chinese Journal of Environmental Engineering

基　　金：国家重点研发计划项目(2022YFC3202702)。

摘　　要：为解决清淤尾水总氮超标的问题,本研究开发的除氮电解器使用泡沫铜电极作为阴极,Ti/IrO_(2)作为阳极,利用电化学作用将废水中的NH_(4)^(+)-N和NO_(3)^(-)-N分别在阳极和阴极发生氧化和还原反应,最终生成氮气脱除。首先利用电化学测试极化曲线研究了阴阳两极的工作电位区间和耐腐蚀性,然后在普通单室电解池中研究了支持电解质、电流密度和电导率对模拟废水中氨氮氧化的影响和去除动力学,认为当电流密度在5~50 mA·cm^(-2),电导率在200~1000μS·cm^(-1)时,氨氮的氧化遵循伪零级动力学。为改善低电导率尾水电解时能耗较高的问题,本研究改进电解池构型使用的流通式电解池压缩了两极板之间的间距,有效减少了欧姆降压,相比于单室电解槽每降低一个数量级的氨氮节省83.783%的能耗。最后,为解决过度反应导致副产物的问题,该研究采取了顺序电解的反应路线,并应用于真实清淤废水的处理,实现在80 min内总氮浓度由28.174 mg·L^(-1)降至0.919 mg·L^(-1),去除率达到95%以上,出水总氮和氨氮浓度远低于我国《城镇污水处理厂污染物排放标准》(GB 18918-2002)中一级A标准中规定的控制浓度,介于我国《地表水环境质量标准》(GB 3838-2002)中地表水Ⅲ类至Ⅱ类水质之间。本研究证明了除氮电解器对于低电导率废水的适用性,为废水的深度脱氮提供了新的思路。To address the over standard issue of total nitrogen in dredging tailwater,a nitrogen removal electrolyzer that employs a copper foam electrode as the cathode and Ti/IrO_(2) as the anode was developed in this study.This system utilizes electrochemical redox reactions to oxidize NH_(4)^(+)-N at the anode and reduce NO_(3)^(-)-N at the cathode,ultimately converting them into nitrogen gas for removal.Initially,the electrochemical polarization curves were used to investigate the working potential ranges and corrosion resistance of both electrodes.Subsequently,the effects of supporting electrolytes,current density,and conductivity on ammonia nitrogen oxidation in simulated wastewater and its removal kinetics were studied in a conventional single-chamber electrolytic cell.The results demonstrated that ammonia nitrogen oxidation followed pseudo-zero-order kinetics at the current density of 5~50 mA·cm^(-2) and the conductivity of 200~1000μS·cm^(-1).To mitigate the high energy consumption associated with electrolyzing tailwater of low conductivity,the electrolytic cell configuration was improved by using a flow-through electrolytic cell that compresses the distance between the two electrode plates,effectively reducing ohmic voltage drop.Compared to a single-chamber electrolytic cell,this improvement saved 83.783%of energy consumption for each order of magnitude reduction in ammonia nitrogen.Finally,to address the issue of byproducts resulting from overreaction,a"sequential electrolysis"reaction route was adopted and used to the treatment of actual dredging wastewater.Within 80 minutes,the total nitrogen concentration decreased from 28.174 mg·L^(-1) to 0.919 mg·L^(-1),achieving a removal rate of over 95%.The concentrations of total nitrogen and ammonia nitrogen in the effluent were far below the control concentrations specified in the Grade 1A standard of China's"Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants"(GB 18918-2002)and fell between the water quality standards for Class III to Class

关 键 词：总氮去除 清淤尾水 电导率 氨氮电氧化 硝酸盐态氮电还原 

分 类 号：X703[环境科学与工程—环境工程]