Sorption behavior and mechanism of hydrophilic organic chemicals to virgin and aged microplastics in freshwater and seawater 机翻标题: 暂无翻译,请尝试点击翻译按钮。

Environmental Pollution
2019 / 246 / Mar.
Shandong Univ, Inst Marine Sci & Technol, Qingdao 266237, Peoples R China;Shanghai Inst Pollut Control & Ecol Secur, Shanghai 200092, Peoples R China;Shanghai Ocean Univ, Coll Marine Ecol & Environm, 999 Huchenghuan Rd, Shanghai 201306, Peoples R China;Tongji Univ, Coll Environm Sci & Enineering, State Key Lab Pollut Control & Resource Reuse, 1239 Siping Rd, Shanghai 200092, Peoples R China;
Liu, Guangzhou;Zhu, Zhilin;Yang, Yuxin;Sun, Yiran;Yu, Fei;Ma, Jie;
Virgin microplastics undergo aging and form oxygen-containing functional groups when they enter the environment. Therefore, the sorption of organic pollutants onto microplastics is not limited to hydrophobic organic pollutants and can also occur with hydrophilic organic pollutants. Therefore, understanding the sorption behaviors and mechanism between aged microplastics and hydrophilic organic pollutants is essential for evaluating the real effects of microplastics in the environment. We investigated the impacts of the UV-accelerated aging of polystyrene (PS) and polyvinylchloride (PVC) on their sorption interactions with ciprofloxacin (CIP). The results of infrared spectroscopy (IR) and scanning electron microscopy (SEM) showed significant surface oxidation and localized microcracks on the aged micro plastics. The sorption kinetics and isotherms models indicated that the sorption capacity of aged microplastics is higher than that of pristine microplastics, and their physical interactions, including partitioning, electrostatic interactions, and intermolecular hydrogen bonding, were the dominant mechanism, as demonstrated by FTIR analysis. Moreover, the sorption capacity of the pristine micro plastics decreased as the degree of crystallinity increased, whereas the opposite trend was observed with aged microplastics, which means that the crystallinity is not the controlling factor. In addition, salinity suppressed adsorption on all the tested microplastics. The pH influences the electrostatic attraction between the microplastics and CIP because CIP has a different charge at different pH values. The results presented herein confirm the importance of studying the adsorption between hydrophilic organic pollutants and aged microplastics because ultimately, all microplastics become aged. Moreover, the effects of aged microplastics with adsorbed hydrophilic chemicals on organisms need to be further studied. (C) 2018 Elsevier Ltd. All rights reserved.
Aged microplastics;Hydrophilic organic pollutants;Ciprofloxacin;Crystallinity;Electrostatic attraction;