Stabilization of hexavalent chromium with pretreatment and high temperature sintering in highly contaminated soil  

作　　者：Haiyan Mou Wenchao Liu Lili Zhao Wenqing Chen Tianqi Ao 

机构地区：[1]College of Architecture and Environment,Sichuan University,Chengdu,610065,China [2]Wuhan Economic&Technological Development Zone(Hannan)Urban Administration Bureau,Wuhan,430056,China [3]Geological Brigade of Sichuan Bureau of Geology&Mineral Resources Geological,Chengdu,611830,China [4]State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu,610065,China

出　　处：《Frontiers of Environmental Science & Engineering》2021年第4期169-181,共13页环境科学与工程前沿（英文）

基　　金：This research was supported by the National Key R&D Program of China(Grant No.2018YFD0800604).We would also like to thank the team members of our laboratory for their valuable discussions.

摘　　要：This study explored the effectiveness and mechanisms of high temperature sintering following prereduction with ferric sulfate(FeSO_(4)),sodium sulfide(Na_(2)S),or citric acid(C_(6)H_(8)O_(7))in stabilizing hexavalent chromium(Cr(VI))in highly contaminated soil.The soil samples had an initial total Cr leaching of 1768.83 mg/L,and Cr(VI)leaching of 1745.13 mg/L.When FeSO_(4)or C_(6)H_(8)O_(7)reduction was followed by sintering at 1000℃,the Cr leaching was reduced enough to meet the Safety Landfill Standards regarding general industrial solid waste.This combined treatment greatly improved the stabilization efficiency of chromium because the reduction of Cr(VI)into Cr(III)decreased the mobility of chromium and made it more easily encapsulated in minerals during sintering.SEM,XRD,TG-DSC,and speciation analysis indicated that when the sintering temperature reached 1000℃,almost all the chromium in soils that had the pre-reduction treatment was transformed into the residual form.At 1000℃,the soil melted and promoted the mineralization of Cr and the formation of new Cr-containing compounds,which significantly decreased subsequent leaching of chromium from the soil.However,without reduction treatment,chromium continued to leach from the soil even after being sintered at 1000℃,possibly because the soil did not fully fuse and because Cr(VI)does not bind with soil as easily as Cr(III).

关 键 词：CHROMIUM Heavy contaminated soil Reduction Sintering STABILIZATION SPECIATION 

分 类 号：X53[环境科学与工程—环境工程]