Enhanced removal of high-As(Ⅲ)from Cl(-Ⅰ)-diluted SO_(4)(-Ⅱ)-rich wastewater at pH 2.3 via mixed tooeleite and(Cl(-Ⅰ)-free)ferric arsenite hydroxychloride formation

作     者：Zidan Yuan Guoqing Zhang Xing Wu Xu Ma Jinru Lin Shaofeng Wang Yongfeng Jia Zidan Yuan;Guoqing Zhang;Xing Wu;Xu Ma;Jinru Lin;Shaofeng Wang;Yongfeng Jia

作者机构：Key Laboratory of Pollution Ecology and Environmental EngineeringInstitute of Applied EcologyChinese Academy of SciencesShenyang 110016China Key Laboratory for Yellow River and Huai River Water Environmental and Pollution ControlMinistry of EducationHenan Key Laboratory for Environmental Pollution ControlSchool of EnvironmentHenan Normal UniversityHenan 453007China Key Laboratory of Industrial Ecology and Environmental Engineering(Ministry of EducationChina)School of Environmental Science and TechnologyDalian University of TechnologyDalian 116024China 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2023年第124卷第2期

页      面：31-41页

核心收录：

学科分类：083002[工学-环境工程] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 08[工学] 0703[理学-化学] 

基　　金：supported by the National Key Research and Development Program of China (No.2019YFC1804400) the National Natural Science Foundation of China (Nos.41877393,41877379,42007364 and 42077309) Youth Innovation Promotion Association CAS (No.2021196) Liao Ning Revitalization Talents Program (Nos.XLYC1807185 and XLYC1807025) 

主　　题：High-As(III) Sulfate Chlorine ion Removal Complex 

摘      要：An advanced cost-saving method of removal of high-As(Ⅲ)from SO_(4)(-Ⅱ)-rich metallurgical wastewater has been developed by diluting the SO_(4)(-Ⅱ)content with As(Ⅲ)-Cl(-Ⅰ)-rich metallurgical wastewater and then by the direct precipitation of As(Ⅲ)with Fe(Ⅲ)at pH 2.3.As(Ⅲ)removal at various SO_(4)(-Ⅱ)/Cl(-Ⅰ)molar ratios and temperatures was investigated.The results showed that 65.2–98.2%of As(Ⅲ)immobilization into solids occurred at the SO_(4)(-Ⅱ)/Cl(-I)molar ratios of 1:1–32 and 15–60℃in 3 days,which were far higher than those in aqueous sole SO4(-Ⅱ)or Cl(-Ⅰ)media at the equimolar SO_(4)(-Ⅱ)or Cl(-Ⅰ)and the same temperature.SO_(4)(-Ⅱ)/Cl(-Ⅰ)molar ratio of 1:4 and 25℃were optimal conditions to reach the As removal maximum.Mixed aqueous SO4(-Ⅱ)and Cl(-Ⅰ)played a synergetic role in the main tooeleite formation together with(Cl(-Ⅰ)-free)ferric arsenite hydroxychloride(FAHC)involving the substitution of AsO_(3)^(3−)for Cl(-Ⅰ)for enhanced As fixation.The competitive complexation among FeH_(2)AsO_(3)^(2+),FeSO_(4)^(+)and FeCl^(2+)complexes was the main mechanism for the maximum As(Ⅲ)precipitation at the SO4(-Ⅱ)/Cl(-I)molar ratio of 1:4.Low As(Ⅲ)immobilization at high temperature with increased Fe(Ⅲ)hydrolysis was due to the formation of As(Ⅲ)-bearing ferrihydrite with the relatively high Fe/As molar ratio at acidic pH.