Leng Yifei, Wang Wei, Cai Huiping, Chang Fengyi, Xiong Wen, Wang Jun
School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan 430068, PR China.
Wuhan Municipal Ecology and Environment Bureau, Jianghan Branch, Wuhan 430015, PR China.
Sci Total Environ. 2023 Feb 1;858(Pt 3):159803. doi: 10.1016/j.scitotenv.2022.159803. Epub 2022 Oct 28.
Microplastic is a new type of pollutant, which can act as a carrier for organic contaminants. It affects the migration and bioavailability of chemicals and potentially threatens the ecology. This work investigated the adsorption kinetics, isotherm and influencing factors of 17β-estradiol (E2) on three dominate microplastics. Then, used molecular dynamics (MD) simulation to analyze the adsorption mechanism. The results showed that E2 adsorption onto microplastics conformed well to the Pseudo-second-order kinetics and Redlich-Petersen isotherm model. The adsorption capacity of E2 on microplastics was polyethylene (PE) > polypropylene (PP) > polystyrene (PS). The small particle size of microplastics was conducive to the adsorption due to its large specific surface area. The thermodynamic parameters demonstrated the adsorption of E2 was a spontaneous and exothermic process, so low temperature was benefit for the adsorption. The MD simulation results indicated the adsorption of E2 on MPs belonged to surface adsorption. The order of E2 adsorption energy by three microplastics obtained by molecular dynamics simulation is consistent with the experimental results. This work may help to understand the molecular adsorption process and provide a theoretical basis for the combined ecotoxicity of microplastics.
微塑料是一种新型污染物，可作为有机污染物的载体。它影响化学物质的迁移和生物有效性，并可能威胁生态环境。本研究考察了17β-雌二醇（E2）在三种主要微塑料上的吸附动力学、等温线及影响因素。然后，采用分子动力学（MD）模拟分析吸附机理。结果表明，E2在微塑料上的吸附符合准二级动力学和Redlich-Petersen等温线模型。E2在微塑料上的吸附量为聚乙烯（PE）>聚丙烯（PP）>聚苯乙烯（PS）。微塑料粒径小，比表面积大，有利于吸附。热力学参数表明，E2的吸附是一个自发的放热过程，因此低温有利于吸附。MD模拟结果表明，E2在微塑料上的吸附属于表面吸附。分子动力学模拟得到的三种微塑料对E2的吸附能顺序与实验结果一致。本研究有助于理解分子吸附过程，为微塑料复合生态毒性提供理论依据。
