Hausmannite is a common low valence Mn oxide mineral,with a distorted spinel struc-ture,in surficial sediments.Although natural Mn oxides often contain various impurities of transitional metals(TMs),few studies have addressed the effect and related mechanism of TM doping on the reactivity of hausmannite with metal pollutants.Here,the reactivity of cobalt(Co)doped hausmannite with aqueous As(Ⅲ)and As(V)was studied.Co doping decreased the point of zero charge of hausmannite and its adsorption capacity for As(V).Despite a reduction of the initial As(Ⅲ)oxidation rate,Co-doped hausmannite could ef-fectively oxidize As(Ⅲ)to As(V),followed by the adsorption and fixation of a large amount of As(V)on the mineral surface.Arsenic K-edge EXAFS analysis of the samples after As(V)adsorption and As(Ⅲ)oxidation revealed that only As(V)was adsorbed on the mineral sur-face,with an average As-Mn distance of 3.25-3.30 ?,indicating the formation of bidentate binuclear complexes.These results provide new insights into the interaction mechanism between TMs and low valence Mn oxides and their effect on the geochemical behaviors of metal pollutants.

Shuang Zhang;Hui Li;Zhongkuan Wu;Jeffrey E.Post;Bruno Lanson;Yurong Liu;Biyun Hu;Mingxia Wang;Limei Zhang;Mei Hong;Fan Liu;Hui Yin

Key Laboratory of Arable Land Conservation(Middle and Lower Reaches of Yangtse River),Ministry of Agriculture and Rural affairs,College of Resources and Environment,Huazhong Agricultural University,Wuhan 430070,China;State Environmental Protection Key Laboratory of Soil Health and Green Remediation,Ministry of Ecology and Environment,Huazhong Agricultural University,Wuhan 430070,China;Department of Crop and Soil Sciences,North Carolina State University,Raleigh,North Carolina 27695,USA;College of Environment,Zhejiang University of Technology,Hangzhou 310014,China;Department of Mineral Sciences,NHB 119,Smithsonian Institution,Washington DC 20013-7012,USA;Université Grenoble Alpes,Grenoble F-38000,France;CNRS,IRD,University of Savoy Mont Blanc,France;ISTerre,Université Gustave Eiffel,France;The Forestry Prospect Design Institute Of Hubei Province,Wuhan 430070,China;College of Grassland,Resources and Environment,Inner Mongolia Agricultural University,Hohhot 010018,China

环境科学学报（英文版）

[1]Shuang Zhang;Hui Li;Zhongkuan Wu;Jeffrey E.Post;Bruno Lanson;Yurong Liu;Biyun Hu;Mingxia Wang;Limei Zhang;Mei Hong;Fan Liu;Hui Yin-.Effects of cobalt doping on the reactivity of hausmannite for As(Ⅲ)oxidation and As(V)adsorption)[J].环境科学学报（英文版）,2022(12):217-226

hausmannite,Hausmannite

Effects,cobalt,doping,reactivity,oxidation,adsorption,common,valence,Mn,mineral,distorted,spinel,struc,ture,surficial,sediments,Although,natural,oxides,often,contain,various,impurities,transitional,metals,TMs,few,studies,have,addressed,effect,related,mechanism,pollutants,Here,Co,doped,aqueous,was,studied,decreased,point,zero,charge,its,capacity,Despite,reduction,initial,rate,could,fectively,oxidize,followed,by,fixation,large,amount,surface,Arsenic,edge,EXAFS,analysis,samples,after,revealed,that,only,adsorbed,average,distance,indicating,formation,bidentate,binuclear,complexes,These,results,provide,new,insights,into,interaction,between,their,geochemical,behaviors

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