Migration and transformation of Sb are affected by Mn(Ⅲ/Ⅳ)associated with lepidocrocite originating from Fe(Ⅱ)oxidation  

作　　者：Yalu Shao Qian Sun Liangkai Wang Weiyong Zhan Hongwei Zhang Hua Zhong 

机构地区：[1]State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,China [2]School of Agriculture and Food,The University of Melbourne,Victoria 3010,Australia [3]College of Agricultural Sciences and Engineering,Hohai University,Nanjing 210098,China

出　　处：《Journal of Environmental Sciences》2022年第5期308-318,共11页环境科学学报（英文版）

基　　金：This work was financed by the National Natural Science Foundation of China(No.42007338);the Natural Science Foundation of Jiangsu Province(No.BK20200531);the National Natural Science Foundation of China(No.51979203)。

摘　　要：Antimony(Sb)is a recognized priority pollutant with toxicity that is influenced by its mi-gration and transformation processes.Oxidation of Fe(Ⅱ)to Fe(Ⅲ)oxides,which is a com-mon phenomenon in the environment,is often accompanied by the formation of Mn(Ⅲ/Ⅳ)and might affect the fate of Sb.In this study,incorporated Mn(Ⅲ)and sorbed/precipitated Mn(Ⅲ/Ⅳ)associated with lepidocrocite were prepared by adding Mn(Ⅱ)during and after Fe(Ⅱ)oxidation,respectively,and the effects of these Mn species on Sb fate were inves-tigated.Our results indicated that the association of these Mn species with lepidocrocite obviously enhanced Sb(Ⅲ)oxidation to Sb(V),while concomitantly inhibiting Sb sorption due to the lower sorption capacity of lepidocrocite for Sb(V)than Sb(Ⅲ).Additionally,Mn oxide equivalents increased in the presence of Sb,indicating that Sb oxidation by Mn(Ⅲ/Ⅳ)associated with lepidocrocite was a continuous recycling process in which Mn(Ⅱ)released from Mn(Ⅲ/Ⅳ)reduction by Sb(Ⅲ)could be oxidized to Mn(Ⅲ/Ⅳ)again.This recycling pro-cess was favorable for effective Sb(Ⅲ)oxidation.Moreover,Sb(Ⅴ)generated from Sb(Ⅲ)ox-idation by Mn(Ⅲ/Ⅳ)enhanced Mn(Ⅱ)sorption at the beginning of the process,and thus favored Mn(Ⅲ/Ⅳ)formation,which could further promote Sb(Ⅲ)oxidation to Sb(V).Over-all,this study elucidated the effects of Mn(Ⅲ/Ⅳ)associated with lepidocrocite arisen from Fe(Ⅱ)oxidation on Sb migration and transformation and revealed the underlying reaction mechanisms,contributing to a better understanding of the geochemical dynamics of Sb.

关 键 词：ANTIMONY Manganese LEPIDOCROCITE SORPTION OXIDATION 

分 类 号：X131[环境科学与工程—环境科学]