Adsorption and desorption behavior of 17α-ethinyl estradiol on microplastics

The endocrine disruptor 17α-Ethinylestradiol (EE2) was used as the target pollutant to study the adsorption kinetics, adsorption isotherm and desorption of five kinds of microplastics: polyamide (PA), polyethylene (PE), polyurethane (TPU), polyvinyl chloride (PVC) and polystyrene (PS). The results of adsorption kinetics and adsorption isotherm showed that the adsorption capacity of five kinds of microplastics for EE2 was in the order of PA > TPU > PE > PVC > PS. TPU and PA had the largest adsorption capacity, which was mainly due to the chemical adsorption of hydrogen bonds; while PE, PS and PVC mainly depended on the interaction of van der Waals force. Because PA and TPU had stronger adsorption capacities for EE2, their desorption capacity was also higher than the other three substances. When the desorption rate was used to reflect the desorption performance of different microplastics, it was found that the desorption rate of EE2 in PS was the highest, while that in PA and TPU were relatively low. Single factor repeated measurement ANOVA was used to analyze the analytical characteristics of EE2 on five kinds of microplastics. There was significant difference between PS and the other four kinds of microplastics, but no significant difference was found in pairwise comparison among these four kinds of microplastics. Although the desorbing rate in gastrointestinal juice was higher than that of deionized water, there was no statistical significance between them. © 2021, Editorial Board of China Environmental Science. All right reserved.