title: Significantly improving trace thallium removal from surface waters during coagulation enhanced by nanosized manganese dioxide.
abstract: Thallium (Tl) is an element of high toxicity and significant accumulation in human body. There is an urgent need for the development of appropriate strategies for trace Tl removal in drinking water treatment plants. In this study, the efficiency and mechanism of trace Tl (0.5 μg/L) removal by conventional coagulation enhanced by nanosized manganese dioxide (nMnO2) were explored in simulated water and two representative surface waters (a river water and a reservoir water obtained from Northeast China). Experimental results showed that nMnO2significantly improve Tl(I) removal from selected waters. The removal efficiency was dramatically higher in the simulated water, demonstrating by less than 0.1 μg/L Tl residual. The enhancement of trace Tl removal in the surface waters decreased to a certain extent. Both adjusting water pH to alkaline condition and preoxidation of Tl(I) to Tl(III) benefit trace Tl removal from surface waters. Data also indicated that competitive cation of Ca2+decreased the efficiency of trace Tl removal, resulting from the reduction of Tl adsorption on nMnO2. Humic acid could largely low Tl removal efficiency during nMnO2enhanced coagulation processes. Trace elemental Tl firstly adsorbed on nMnO2and then removed accompanying with nMnO2settling. The information obtained in the present study may provide a potential strategy for drinking water treatment plants threatened by trace Tl.
authors: Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Faculty of Urban Construction and Environmental Engineering, Chongqing University, China. Electronic address: hfxl@cqu.edu.cn.
authors: Xiaoliu
authors: X
authors: Huangfu
authors: Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Faculty of Urban Construction and Environmental Engineering, Chongqing University, China.
authors: Chengxue
authors: C
authors: Ma
authors: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, China. Electronic address: majun@hit.edu.cn.
authors: Jun
authors: J
authors: Ma
authors: Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Faculty of Urban Construction and Environmental Engineering, Chongqing University, China.
authors: Qiang
authors: Q
authors: He
authors: Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Faculty of Urban Construction and Environmental Engineering, Chongqing University, China.
authors: Chun
authors: C
authors: Yang
authors: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, China.
authors: Jin
authors: J
authors: Jiang
authors: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, China.
authors: Yaan
authors: Y
authors: Wang
authors: Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Faculty of Urban Construction and Environmental Engineering, Chongqing University, China.
authors: Zhengsong
authors: Z
authors: Wu
mesh_terms: D000327:Adsorption; D002118:Calcium; D002681:China; D005618:Fresh Water; D006801:Humans; D006812:Humic Substances; D006863:Hydrogen-Ion Concentration; D017895:Manganese Compounds / Q000737:chemistry; D053758:Nanoparticles; D010087:Oxides / Q000737:chemistry; D013793:Thallium / Q000032:analysis / Q000302:isolation & purification*; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D006812:Humic Substances; D017895:Manganese Compounds; D010087:Oxides; D014874:Water Pollutants, Chemical; D014867:Water; D013793:Thallium; D002118:Calcium; C016552:manganese dioxide
keywords: Drinking water; Enhanced coagulation; Nanosized manganese dioxide; Trace thallium removal