(可降解)微塑料颗粒吸附有机污染物及对其生物有效性的影响

Adsorption of organic pollutants on (degradable) microplastics and the influences on their bioavailability

微塑料是环境中一类不断增加的新兴污染物,工业生产活动以及日常生活是环境中微塑料的主要来源,同时农用塑料薄膜的残留对其也有贡献.鉴于不可降解塑料在环境中的持久性,作为传统塑料的替代品,可降解塑料的应用越来越多.然而,当前针对陆地系统微塑料的研究主要集中于不可降解材质的微塑料,针对可降解塑料作为微塑料来源的研究则十分匮乏.由于微塑料的憎水性和较大比表面积,进入环境中的微塑料能够通过分配作用和表面吸附作用大量吸附环境中的有机污染物从而改变被吸附物质的生物有效性;同时随着塑料的风化,生产过程中添加的大量助剂也会逐渐进入环境中.与不可降解微塑料相比,可降解微塑料的性质有很大不同,可降解微塑料与污染物的相互作用及对其生物有效性的影响也与不可降解微塑料不同.另外,可降解微塑料进入环境后,粒径及表面性质可在较短时间内产生变化,这些变化对可降解微塑料与有机污染物的相互作用及对所吸附有机污染物的生物有效性的影响有待研究.

Microplastics are increasing emerging contaminants in the environment,and the industry production and daily life as well as debris of agriculture mulch are the main sources. As the substitute of traditional non-degradable plastics,the use ofdegradable plastics has increased continually in recent years,however,few researches have referred to degradable plastics as a potential source of microplastics. Research about microplastics in terrestrial environment has been primarily focused on non-degradable microplastics; it has been found that microplastics could adsorb large quantities of organic pollutants by partition and surface adsorption due to their hydrophobicity and large specific surface area,which further influences the bioavailability of these adsorbed pollutants. Besides,in response to the weathering effects,various additives added during the production of plastics would gradually enter the environment. Compared with non-degradable microplastics,degradable microplastics own varied properties which lead to different interaction patterns between microplastics and organic pollutants as well as influences on the bioavailability of pollutants. Besides,degradable microplastics would undergo changes of sizes and surface properties in relatively short periods after entering the environment; and these changes would have significant impacts on the adsorption and bioavailability of organic pollutants,which deserve intensive research.