Highly inhibited transport of dissolved thallium(I) in manganese oxide-coated sand: Chemical condition effects and retention mechanisms  

作　　者：Xiaoliu Huangfu Ziqiang Liu Hainan Wang Qiang He Hongxia Liu Caihong Liu 

机构地区：[1]Key Laboratory of Eco-Environments in Three Gorges Reservoir Region,Ministry of Education,College of Environment and Ecology,Chongqing University,Chongqing 400044,China [2]State Key Laboratory of Pollution Control and Resource Reuse,School of Environment,Nanjing University,Nanjing 210023,China

出　　处：《Journal of Environmental Sciences》2023年第7期104-114,共11页环境科学学报（英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(Nos.51878092 and 52070029)。

摘　　要：Thallium contamination in water can cause great danger to the environment.In this study,we synthesized manganese oxide-coated sand(MOCS)and investigated the transport and retention behaviors of Tl(I)in MOCS under different conditions.Characterization methods combined with a two-site nonequilibrium transport model were applied to explore the retentionmechanisms.The results showed that Tl(I)mobility was strongly inhibited in MOCS media,and the retention capacity calculated from the fitted model was 510.41 mg/g under neutral conditions.The retention process included adsorption and oxidative precipitation by the manganese oxides coated on the sand surface.Cotransport with the same concentration of Mn(II)led to halving Tl(I)retention due to competition for reactive sites.Enhanced Tl(I)retention was observed under alkaline conditions,as increasing pH promoted electronegativity on the media surface.Moreover,the competitive cation Ca^(2+)significantly weakened Tl(I)retention by occupying adsorption sites.These findings provide new insights into understanding Tl(I)transport behavior in water-saturated porous media and suggest that manganese oxide-coated sand can be a cost-effective filter media for treating Tl-contaminated water.

关 键 词：Thallium(I) Manganese oxide-coated sand Transport and retention Adsorption Oxidative precipitation 

分 类 号：X703[环境科学与工程—环境工程]