Luo Ying, Wang Zhe, Zhang Yong-De, Zhang Jia-Qian, Zeng Qiu-Ping, Zhang Zhen-Long, Tian Duan, Li Chao, Peng Chao-Liang, Ye Kai, Chen Yi-Ming, Huang Feng-Yu, Wang Yu-Ping, Ma Xiao-Ya, Chen Li
College of Environment and Resources, Southwest University of Science & Technology, Mianyang, Sichuan 621010, China.
College of Environment and Resources, Southwest University of Science & Technology, Mianyang, Sichuan 621010, China.
J Hazard Mater. 2024 May 5;469:133990. doi: 10.1016/j.jhazmat.2024.133990. Epub 2024 Mar 7.
Heavy metal migration in soil poses a serious threat to the soil and groundwater. Understanding the migration pattern of heavy metals (HMs) under different factors could provide a more reasonable position for pollution evaluation and targetoriented treatment of soil heavy metal. In this study, the migration behavior of Pb and Cd in co-contaminated soil under different pH and ionic strength (NaCl concentration) was simulated using convective dispersion equation (CDE). We predicted the migration trends of Pb and Cd in soils after 5, 10, and 20 years via PHREEQC. The results showed that the migration time of Cd in the soil column experiment was about 60 days faster than that of Pb, and the migration trend was much steeper. The CDE was proved to describe the migration behavior of Pb and Cd (R > 0.75) in soil. The predicted results showed that Cd migrated to 15-20 cm of soil within 7 years and Pb stayed mainly in the top 0-6 cm of soil within 5 years as the duration of irrigation increased. Overall, our study is expected to provide new insight into the migration of heavy metal in soil ecosystems and guidance for reducing risk of heavy metal in the environment.
土壤中的重金属迁移对土壤和地下水构成严重威胁。了解不同因素下重金属（HMs）的迁移模式可为土壤重金属污染评估和靶向治理提供更合理的依据。本研究采用对流弥散方程（CDE）模拟了不同pH值和离子强度（NaCl浓度）下复合污染土壤中Pb和Cd的迁移行为。通过PHREEQC预测了5年、10年和20年后Pb和Cd在土壤中的迁移趋势。结果表明，在土柱实验中Cd的迁移时间比Pb快约60天，且迁移趋势更陡。CDE被证明能够描述Pb和Cd在土壤中的迁移行为（R>0.75）。预测结果表明，随着灌溉时间的增加，7年内Cd迁移至土壤15 - 20 cm深处，5年内Pb主要停留在土壤表层0 - 6 cm处。总体而言，我们的研究有望为土壤生态系统中重金属的迁移提供新的见解，并为降低环境中重金属风险提供指导。
