环境工程学报2025，Vol.19Issue(2)：333-341,9.DOI:10.12030/j.cjee.202409150
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
摘要
Abstract
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/IrO2 as the anode was developed in this study.This system utilizes electrochemical redox reactions to oxidize NH4+-N at the anode and reduce NO3--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 200～1 000 μS·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 Ⅱ surface water in the"Environmental Quality Standards for Surface Water"(GB 3838-2002)in China.This study demonstrates the applicability of the nitrogen removal electrolyzer for low-conductivity wastewater and provides a new approach for advanced nitrogen removal from wastewater.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Key words
nitrogen removal/dredging tailwater/electrical conductivity/electrooxidation of ammonia/electroreduction of nitrate分类
环境科学引用本文复制引用
邢思奇,易娟,吴旭..除氮电解器应用于低电导率清淤尾水的性能研究[J].环境工程学报,2025,19(2):333-341,9.基金项目
国家重点研发计划项目(2022YFC3202702) （2022YFC3202702）
