title: Moisture content-affected electrokinetic remediation of Cr(VI)-contaminated clay by a hydrocalumite barrier.
abstract: An electrokinetic-permeable reaction barrier (EK-PRB) system was introduced in this study with hydrocalumite as the barrier material. The combined system effectively remediated the Cr(VI)-contaminated clay after a 72-h treatment, and the Cr(VI) removal efficiency increased with the initial soil moisture content. Further evidence was found that the changing soil pH value and current density were highly associated with the initial moisture content, showing its important roles in the Cr(VI) removal process. Additionally, the total Cr removal efficiency was much lower than that of Cr(VI) owing to the partial conversion of Cr(VI) to Cr(III) in the electrokinetic remediation process. Under high soil moisture conditions (40%), the removal efficiency of Cr(VI) and total Cr was 96.6 and 67.3%, respectively. Further analysis also revealed the new mineral phase, chromate hydrocalumite, for Cr fixation in the hydrocalumite barrier, which was significantly affected by the initial soil moisture content. Our results showed that the EK-PRB system with a hydrocalumite barrier is highly promising with great potential for the effective remediation of Cr(VI)-contaminated clay and engineering implementation.
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No.99 Shangda Rd, Shanghai, 200444, People's Republic of China.
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Xu
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No.99 Shangda Rd, Shanghai, 200444, People's Republic of China.
authors.forename: Xiangjian
authors.initials: X
authors.lastname: Xu
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No.99 Shangda Rd, Shanghai, 200444, People's Republic of China.
authors.forename: Hetian
authors.initials: H
authors.lastname: Hou
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No.99 Shangda Rd, Shanghai, 200444, People's Republic of China.
authors.forename: Jia
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YW, UK.
authors.forename: Dayi
authors.initials: D
authors.lastname: Zhang
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No.99 Shangda Rd, Shanghai, 200444, People's Republic of China. grqian@shu.edu.cn.
authors.forename: Guangren
authors.initials: G
authors.lastname: Qian
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D002857:Chromium / Q000032:analysis*; D000077215:Clay; D004563:Electrochemistry; D052918:Environmental Restoration and Remediation / Q000379:methods*; D008903:Minerals / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D014867:Water / Q000032:analysis*
chemical_list: D000538:Aluminum Silicates; D008903:Minerals; D012987:Soil; D012989:Soil Pollutants; D014867:Water; D002857:Chromium; C074702:chromium hexavalent ion; D000077215:Clay
keywords: Cr(VI)-contaminated clay; Electrokinetic; Hydrocalumite; Moisture content; Permeable reaction barrier (PRB)