Chromium transformation driven by iron redox cycling in basalt-derived paddy soil with high geological background values

作     者：Ke Zhang Yang Yang Wenting Chi Guojun Chen Yanhong Du Shiwen Hu Fangbai Li Tongxu Liu Ke Zhang;Yang Yang;Wenting Chi;Guojun Chen;Yanhong Du;Shiwen Hu;Fangbai Li;Tongxu Liu

作者机构：Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South ChinaGuangdong Key Laboratory of Integrated Agro-environmental Pollution Control and ManagementInstitute of Eco-environmental and Soil SciencesGuangdong Academy of SciencesGuangzhou 510650China University of Chinese Academy of SciencesBeijing 100049China 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2023年第125卷第3期

页      面：470-479页

核心收录：

学科分类：12[管理学] 1204[管理学-公共管理] 082803[工学-农业生物环境与能源工程] 08[工学] 0828[工学-农业工程] 120405[管理学-土地资源管理] 

基　　金：supported by the National Natural Science Foundation of China (No. 41807026) China Postdoctoral Science Foundation (No. 2021M700888) GDAS’ Project of Science and Technology Development (No. 2021GDASYL20210302003) the China Agriculture Research System, assigned to Ministry of Finance & Ministry of Agriculture and Rural Affairs 

主　　题：Chromium Paddy soil Iron oxides Redox High geological background 

摘      要：The flooding and drainage of paddy fields has great effects on the transformation of heavy metals, however, the transformation of Cr in basalt-derived paddy soil with high geological background values was less recognized. The typical basalt-derived paddy soil was incubated under alternating redox conditions. The Cr fractions and the dynamics of Fe/N/S/C were examined. The HCl-extractable Cr increased under anaerobic condition and then decreased during aerobic stage. The UV-vis spectra of the supernatant showed that amounts of colloids were released under anaerobic condition, and then re-aggregated during aerobic phase. The scanning transmission electron microscopy(TEM) and X-ray photoelectron spectroscopy(XPS) revealed that Fe oxides were reduced and became dispersed during anaerobic stage, whereas Fe(Ⅱ) was oxidized and recrystallized under aerobic condition. Based on these results, a kinetic model was established to further distinguish the relationship between the transformation of Cr and Fe. During anaerobic phase, the reduction of Fe(Ⅲ) oxides not only directly released the structurally bound Cr, but also enhanced the breakdown of soil aggregation and dissolution of organic matter causing indirect mobilization of Cr. During aerobic phase, the oxidation of Fe (Ⅱ) and further recrystallization of newly formed Fe(Ⅲ) oxides might induce the re-aggregation of soil colloids and further incorporation of Cr. In addition,the kinetic model of Cr and Fe transformation was further verified in the pot *** model-based findings demonstrated that the Cr transformation in the basalt-derived paddy soil with high geological background values was highly driven by redox sensitive iron cycling.