Effect of iron ion configurations on Ni^(2+) removal in electrocoagulation  

作　　者：Xiaoliu Lü Tao Xu Yihui Zhou Qingjuan Peng Jinhua Ou Bonian Hu Zhihui Xie Xiping Lei Gang Yu 

机构地区：[1]College of Chemistry and Chemical Engineering,Hunan University,Changsha 410082,China [2]Research Institute of New Building Materials,Hunan Institute of Technology,Hengyang 421008,China [3]Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province,College of Chemistry and Chemical Engineering,China West Normal University,Nanchong 637002,China [4]Hunan Zihong Ecology Technology Co.,Ltd.,Changsha 410000,China

出　　处：《Journal of Environmental Sciences》2023年第2期823-834,共12页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No. 51974115);the National Natural Science Foundation of Hunan Province of China (No. 2020JJ4145);the Key R & D Plan Project of Changsha (No. 2021-440)

摘　　要：Electrocoagulation(EC)has been widely used to treat the heavymetal wastewater in industry.A novel process of sinusoidal alternating current electrocoagulation(SACC)is adopted to remove Ni2+in wastewater in this study.The morphology of precipitates and the distribution of the main functional iron configurations were investigated.Ferron timed complex spectroscopy can identify the monomeric iron configurations[Fe(a)],oligomeric iron configurations[Fe(b)]and polymeric iron configurations[Fe(c)].The optimal operating conditions of SACC process were determined through single-factor experiments.The maximum Ni2+removal efficiency[Re(Ni^(2+))]was achieved under the conditions of pH0=7,current density(j)=7 A/m^(2),electrolysis time(t)=25 min,c0(Ni^(2+))=100 mg/L.At pH=7,the proportion of Fe(b)and Fe(c)in the system was 50.4 at.% and 23.1 at.%,respectively.In the SACC process,Fe(b)and Fe(c)are themain iron configurations in solution,while Fe(c)are the vastmajority of the iron configurations in the direct current electrocoagulation(DCC)process.Re(Ni2+)is 99.56% for SACC and 98.75% for DCC under the same optimum conditions,respectively.The precipitates produced by SACC have a high proportion of Fe(b)configurations with sphericalα-FeOOH andγ-FeOOH structures which contain abundant hydroxyl groups.Moreover,it is demonstrated that Fe(b)has better adsorption capacity than Fe(c)through adsorption experiments of methyl orange(MO)dye.Fe(a)configurations in the homogeneous solution had no effect on the removal of nickel.

关 键 词：ELECTROCOAGULATION Nickel wastewater Iron configurations Alternating current Polynuclear iron-hydroxyl complex 

分 类 号：X703[环境科学与工程—环境工程]