The effect of thermal treatment on the transformation and transportation of arsenic and cadmium in soil  

作　　者：Fengping Zhou Meina Guo Nan Zhao Qianting Xu Tuokun Zhao Weihua Zhang Rongliang Qiu 

机构地区：[1]Guangdong Provincial Key Laboratory of Environmental Pollution and Remediation Technology,Guangdong Provincial Engineering Research Center for Heavy Metal Contaminated Soil Remediation,School of Environmental Science and Engineering,Sun Yat-sen University,Guangzhou 510275,China [2]Shenzhen Research Institute,Sun Yat-sen University,Shenzhen 518057,China [3]National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China,Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management,Institute of Eco-environmental and Soil Sciences,Guangdong Academy of Sciences,Guangzhou 510650,China [4]Guangdong Provincial Key Laboratory of Agricultural&Rural Pollution Abatement and Environmental Safety,School of Natural Resources and Environment,South China Agricultural University,Guangzhou 510642,China [5]Ganjiang Innovation Academy,Chinese Academy of Sciences,Ganzhou 341000,China

出　　处：《Journal of Environmental Sciences》2024年第11期205-215,共11页环境科学学报（英文版）

基　　金：supported by the National Key Research and Development Program of China(No.2019YFC1803900);the National Natural Science Foundation of China(No.42277486).

摘　　要：Thermal treatment can effectively decontaminate soils but alter their properties.Previous research mainly focused on volatile organic compounds andmetals,i.e.Hg,neglecting nonvolatile metal(loid)s.This study aimed to investigate Cd and As transformation during aerobic and anaerobic calcination.The results showed that both aerobic and anaerobic calcination increased soil pH by reducing soil organic matter(SOM)content,which also influenced the cation exchange capacity(CEC)and the leaching behavior of Cd and As in the soil.The total concentrations of Cd and As in the calcined soils varied depending on the calcination temperature and atmosphere.When the aerobic calcination temperature exceeded 700℃,Cd volatilized as CdCl_(2),while anaerobic calcination at relatively low temperatures(600℃)involved reductive reactions,resulting in the formation of metallic Cd with a lower boiling point.Similarly,As volatilized at 800℃aerobically and 600℃anaerobically.The formation of As-based minerals,particularly Ca3(AsO4)2,hindered its gasification,whereas anaerobic calcination promoted volatilization efficiency through the generation of C-As(III)based gaseous components with lower boiling points.Contrasting trends were observed in the TCLP-extractable Cd and As contents of the calcined soils.Over 70%of TCLP-extractable Cd contents were suppressed after thermal treatment,attributed to the elevated pH and reduced CEC of the soil,as well as volatilization.However,TCLP-extractable As contents increased with elevated temperatures,likely due to the desorption of AsO43−and re-adsorption of gaseous As2O3 during cooling.These findings have implications for assessing the environmental impact of thermal treatment and provide insights for remediation strategies concerning Cd and As-contaminated soils.

关 键 词：Thermal treatment SOIL CADMIUM ARSENIC TRANSFORMATION 

分 类 号：X503[环境科学与工程—环境工程]