老化作用对微塑料与镉在运河沿岸土壤中共迁移影响

来源：中国环境科学杂志2024年第11期北京时间：

作者：杨蓉, 赵凡, 桂向阳, 曹峰赫, 李博文, 陈明

单位：1. 苏州科技大学环境科学与工程学院, 江苏 苏州 215009;2. 苏州大学教育学院, 江苏 苏州 215123;3. 上海交通大学环境科学与工程学院, 上海 200240

摘要：Packed column experiments and numerical simulations were conducted to investigate the effect of microplastics (MPs) aging on their co-transport with cadmium Cd(II) in canal soils. The aging of MPs facilitated their transport in soils. Compared with pristine (unaged) MPs, the transportability of aged MPs in soils increased by 28.3%~184%. This is likely because of the enhanced negative charges of MPs after aging, resulting in enhanced stability of MP suspensions and stronger repulsive energy barrier between aged MPs and soil particles. For the co-transport of MPs and Cd(II), compared with MPs-alone, the presence of Cd(II) inhibited the transport of MPs in soils, decreasing by 0.20~0.33 times. The aging effect of MPs further reinforced the inhibited transport of MPs by Cd(II), decreasing by 0.21~0.59times. In contract, MPs acted as carriers that enhance the transport of adsorbed Cd(II) in soils. Furthermore, the aged MPs exhibited greater enhancement effect on Cd(II) transport, increasing by 0.56~3.2 times, mainly due to the increased transport of aged MPs that can carry more adsorbed Cd(II). A two-site kinetic retention model was successfully employed to simulate the co-transport of MPs and Cd(II) in soils. The modeling results illustrate the effect of the aging on co-transport of MPs and Cd(II) and further indicate that the aged MPs increased the transport solute flux and potential risks of Cd(II) in soils.

关键词：微塑料,重金属镉,共迁移,吸附,数值模拟

基金资助：国家自然科学基金资助项目(42077112);江苏省研究生实践创新计划项目(SJCX23_1747)