A review of cadmium sorption mechanisms on soil mineral surfaces revealed from synchrotron-based X-ray absorption fine structure spectroscopy:Implications for soil remediation  

作　　者：Xinxin MO Matthew G.SIEBECKER Wenxian GOU Ling LI Wei LI 

机构地区：[1]Key Laboratory of Surficial Geochemistry,Ministry of Education,School of Earth Sciences and Engineering,Nanjing University,Nanjing 210023,China [2]Department of Plant and Soil Science,Texas Tech University,Lubbock TX 79409(USA) [3]State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China

出　　处：《Pedosphere》2021年第1期11-27,共17页土壤圈（英文版）

基　　金：funded by the National Natural Science Foundation of China (Nos. 41722303, 41977267, and 41473084);the National Key R&D Program of China (No. 2017YFD0800303);the financial support of the Opening Fund of State Key Laboratory of Environmental Geochemistry (No. SKLEG2019712);the National 1 000 Youth Talent Program of China。

摘　　要：The sorption of cadmium(Cd) is one of the most important chemical processes in soil, affecting its fate and mobility in both soil and water and ultimately controlling its bioavailability. In order to fundamentally understand the sorption/desorption of Cd in soil systems, X-ray absorption fine structure spectroscopy(XAFS) has been applied in numerous studies to provide molecular-level information that can be used to characterize the surface adsorption and precipitation reactions that Cd can undergo. This information greatly improves our current knowledge of the possible chemical reactions of Cd in soil. This paper critically reviews the mechanisms of Cd sorption/desorption at the mineral-water interface based on XAFS studies performed over the past twenty years. An introduction to the basic concepts of sorption processes is provided, followed by a detailed interpretation of XAFS theory and experimental data collection and processing,ending finally with a discussion of the atomic/molecular-scale Cd sorption mechanisms that occur at the soil mineral-water interface. Particular emphasis is placed on literature that discusses Cd adsorption and speciation when associated with iron, manganese, and aluminum oxides and aluminosilicate minerals.Multiple sorption mechanisms by which Cd is sorbed by these minerals have been found, spanning from outer-sphere to inner-sphere to surface precipitation,depending on mineral type, surface loading, and pH. In addition, the application of complementary techniques(e.g.,113 Cd nuclear magnetic resonance(NMR) and molecular dynamics simulation) for probing Cd sorption mechanisms is discussed. This review can help to develop appropriate strategies for the environmental remediation of Cd-contaminated soils.

关 键 词：aluminosilicate minerals aluminum oxide BIOAVAILABILITY heavy metal iron oxide manganese oxide mineral-water interface molecular-scale sorption mechanisms 

分 类 号：X53[环境科学与工程—环境工程]