分子动力学
环境修复
化学物理
动力学(音乐)
化学
环境化学
环境科学
生物系统
生物物理学
材料科学
纳米技术
污染
计算化学
物理
生物
生态学
声学
作者
Yan Ke,Zhaoyun Chai,Tianyu Li,B. Duan,Chengwen Xiao,Xiangyu Liu,Xinyu Li
标识
DOI:10.1016/j.envres.2024.119085
摘要
Electrokinetic-Permeable Reaction Barrier (EK-PRB) coupled remediation technology can effectively treat heavy metal-contaminated soil near coal mines. This study was conducted on cadmium (Cd), a widely present element in the soil of the mining area. To investigate the impact of the voltage gradient on the remediation effect of EK-PRB, the changes in current, power consumption, pH, and Cd concentration content during the macroscopic experiment were analyzed. A three-dimensional visualized kaolinite-heavy metal-water simulation system was constructed and combined with the Molecular Dynamics (MD) simulations to elucidate the migration mechanism and binding active sites of Cd on the kaolinite (001) crystalline surface at the microscopic scale. The results showed that the voltage gradient positively correlates with the current, power consumption, and Cd concentration during EK-PRB remediation, and the average removal efficiency increases non-linearly with increasing voltage gradient. Considering power consumption, average removal efficiency, and cost-effectiveness, the voltage range is between 1.5 and 3.0 V/cm, with 2.5 V/cm being the optimal value. The results of MD simulations and experiments correspond to each other. Cd2+ formed a highly stable adsorption structure in contrast to the Al-O sheet on the kaolinite (001) crystalline surface. The mean square displacement (MSD) curve of Cd2+ under the electric field exhibits anisotropy, the total diffusion coefficient DTotal increases and the Cd2+ migration rate accelerates. The electric field influences the microstructure of Cd2+ complexes. With the enhancement of the voltage gradient, the complexation between Cd2+ and water molecules is enhanced, and the interaction between Cd2+ and Cl- in solution is weakened.
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