School of Ocean Science and Technology, Dalian University of Technology, Panjin, 124221, China.
State Key Laboratory of Environmental Criteria & Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
Chemosphere. 2020 Oct;257:127225. doi: 10.1016/j.chemosphere.2020.127225. Epub 2020 May 28.
The role of plastic as a vector for bioaccumulation of hydrophobic organic pollutants has been widely studied. However, the interactions between microplastics (MPs) and crude oil, and the transfer kinetics of sorbed oil from ingested MPs into aquatic biota are largely unknown. In this study, interactions between MPs and crude oil in seawater and digestive tract mimic of aquatic biota have been examined. To mimic the living, transportation and cooking conditions of aquatic organisms, sorption and desorption behaviors were investigated under room temperature-bath (25 °C), ice-bath (0∼4 °C) and boiling water-bath (95∼100 °C), and pH was set as 4 and 7 for the simulated gut fluid. The results showed that sorption capacity of polyethylene (PE) MPs for crude oil in seawater was higher than that in intestinal tract, indicating more oil residue in aqueous phase of gut fluid in the present of organic particles. The sorption kinetics models were well fitted to the pseudo-order model, and isotherms models were well fitted to the Freundlich model. In addition, the results demonstrated that temperature played a significant effect on crude oil viscosity, and the sorption capacity under different temperatures was in the order of 25 °C > 95∼100 °C > 0∼4 °C, indicating that more oil was remained in aqueous phase at boiling water-bath and ice-bath. The increment of pH enhances the sorption capacities of PE MPs. Moreover, the desorption experiment has supplemented the current findings from the sorption experiments.
塑料作为疏水性有机污染物生物蓄积的载体的作用已得到广泛研究。然而，微塑料（MPs）与原油之间的相互作用，以及从摄入的 MPs 中转移到水生生物区系的吸附油的传递动力学在很大程度上尚不清楚。在这项研究中，检查了 MPs 与海水中原油之间的相互作用，以及水生生物的消化道模拟物。为了模拟水生生物的生活、运输和烹饪条件，在室温浴（25°C）、冰浴（0∼4°C）和沸水浴（95∼100°C）下研究了吸附和解吸行为，并将 pH 值设定为 4 和 7 用于模拟肠道液。结果表明，PE MPs 在海水中对原油的吸附能力高于在肠道中的吸附能力，这表明在有有机颗粒存在的情况下，肠道液的水相中残留的油更多。吸附动力学模型很好地符合拟一级动力学模型，等温线模型很好地符合 Freundlich 模型。此外，结果表明，温度对原油粘度有显著影响，不同温度下的吸附能力顺序为 25°C>95∼100°C>0∼4°C，这表明在沸水浴和冰浴中，更多的油残留在水相。pH 值的增加提高了 PE MPs 的吸附能力。此外，解吸实验补充了吸附实验的现有发现。
