1. Guangdong Industry Technical College, Guangzhou 510300, China;
2. Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection, Nanjing 210042, China;
3. School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China;
4. School of Geography and Planning, Sun Yat-sen University, Guangzhou 510275, China;
5. Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou 510275, China
An acid sulfate Cu polluted soil with low-organic matter content was employed for the goal of understanding the effects of AVS on migration and transformation of Cu. Provided with artificial carbon source, the generation of acid-volatile sulfide (AVS) in each column layer, the distribution of total Cu and porewater Cu in vertical profile and the speciation transformation of Cu were investigated under flooding condition. During the flooding period, considerable AVS was generated due to the reduction of sulfate, which could promote transformation of free Cu into inert sulfide phase and residual phase. The generation of AVS in different column layer differed greatly, with the most abundance in the top layer, and decreased sharply with the depth. The difference of AVS content in each layer resulted in a vertical gradient difference of free Cu content in porewater, which would drive the mobile Cu migration from deeper layer to upper layer, and transformed into copper sulfide phase. The inert and total Cu in top layer increased in the processes, combined with the decreased mobile and total Cu in deeper layer, which may greatly lower the potential ecological risk and bioavailability of Cu in acid sulfate soil
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