Abstract:
Microplastics (MPs) have been defined as particles of size < 5 mm and are characterized by hydrophobicity and large surface areas. MPs interact with co-occurring hydrophobic organic contaminants (HOCs) via sorption-desorption processes in aquatic and terrestrial environments. Ingestion of MPs by living organisms may increase exposure to HOC levels. The key mechanisms for the sorption of HOCs onto MPs are hydrophobic interaction, electrostatic interaction, π-π interactions, hydrogen bonding, and Van der Waals forces (vdW). Polymer type, UV-light-induced surface modifications, and the formation of oxygen-containing functional groups have a greater influence on electrostatic and hydrogen bonding interactions. In contrast, the formation of oxygen-containing functional groups negatively influences hydrophobic interaction. MP characteristics such as crystallinity, weathering, and surface morphology affect sorption capacity. Matrix properties such as pH, ionic strength, and dissolved organic matter (DOM) also influence sorption capacity by exerting synergistic/antagonistic effects. We reviewed the mechanisms of HOC sorption onto MPs and the polymer and matrix properties that influence the HOC sorption. Knowledge gaps and future research directions are outlined.
摘要:
微塑料(MPs)被定义为尺寸<5mm的颗粒,其特征在于疏水性和大表面积。在水生和陆地环境中,MPs通过吸附-解吸过程与共存的疏水性有机污染物(HOC)相互作用。活生物体摄入MPs可能会增加HOC水平的暴露。HOCs吸附到MPs上的关键机制是疏水相互作用,静电相互作用,π-π相互作用,氢键,和范德华力(vdW)。聚合物类型,紫外光诱导的表面改性,含氧官能团的形成对静电和氢键相互作用有较大影响。相比之下,含氧官能团的形成对疏水相互作用有负面影响。MP特性,如结晶度,风化,和表面形貌影响吸附能力。基质特性,如pH,离子强度,和溶解有机物(DOM)也通过发挥协同/拮抗作用来影响吸附能力。我们回顾了HOC吸附到MPs上的机理以及影响HOC吸附的聚合物和基质特性。概述了知识差距和未来的研究方向。