Simultaneous removal of Cd(Ⅱ)and As(Ⅴ)by ferrihydrite-biochar composite:Enhanced effects of As(Ⅴ)on Cd(Ⅱ)adsorption  

作　　者：Wenjun Zeng Yang Lu Jingyan Zhou Jie Zhang Yuanxiao Duan Changxun Dong Wencheng Wu 

机构地区：[1]College of Sciences,Nanjing Agricultural University,Nanjing 210095,China [2]South China Institute of Environmental Sciences,Ministry of Ecology and Environment,Guangzhou 510655,China [3]Guangdong Engineering&Technology Research Center for System Control of Livestock and Poultry breeding Pollution,Guangzhou 510655,China

出　　处：《Journal of Environmental Sciences》2024年第5期267-280,共14页环境科学学报（英文版）

基　　金：supported by the National Key R&D Program of China(No.2019YFC1803900);the National Natural Science Foundation of China(No.42107264);Guangdong Basic and Applied Basic Research Foundation(No.2020A1515110610);Guangzhou Basic and Applied Basic Research Foundation(No.202002030364)。

摘　　要：The coexistence of cadmium(Cd(Ⅱ))and arsenate(As(Ⅴ))pollution has long been an environmental problem.Biochar,a porous carbonaceous material with tunable functionality,has been used for the remediation of contaminated soils.However,it is still challenging for the dynamic quantification and mechanistic understanding of the simultaneous sequestration of multi-metals in biochar-engineered environment,especially in the presence of anions.In this study,ferrihydrite was coprecipitated with biochar to investigate how ferrihydritebiochar composite affects the fate of heavy metals,especially in the coexistence of Cd(Ⅱ)and As(Ⅴ).In the solution system containing both Cd(Ⅱ)and As(Ⅴ),the maximum adsorption capacities of ferrihydrite-biochar composite for Cd(Ⅱ)and As(Ⅴ)reached 82.03μmol/g and 531.53μmol/g,respectively,much higher than those of the pure biochar(26.90μmol/g for Cd(Ⅱ),and 40.24μmol/g for As(Ⅴ))and ferrihydrite(42.26μmol/g for Cd(Ⅱ),and 248.25μmol/g for As(Ⅴ)).Cd(Ⅱ)adsorption increased in the presence of As(Ⅴ),possibly due to the changes in composite surface charge in the presence of As(Ⅴ),and the increased dispersion of ferrihydrite by biochar.Further microscopic and mechanistic results showed that Cd(Ⅱ)complexed with both biochar and ferrihydrite,while As(Ⅴ)was mainly complexed by ferrihydrite in the Cd(Ⅱ)and As(Ⅴ)coexistence system.Ferrihydrite posed vital importance for the co-adsorption of Cd(Ⅱ)and As(Ⅴ).The different distribution patterns revealed by this study help to a deeper understanding of the behaviors of cations and anions in the natural environment.

关 键 词：FERRIHYDRITE Biochar Cadmium ARSENATE Simultaneous sequestration Binding mechanisms 

分 类 号：X703[环境科学与工程—环境工程]