O_(3)对PET微塑料吸附有机污染物的影响机制

The Influence Mechanism of O_(3) on the Adsorption of Organic

微塑料对环境污染物具有较高的吸附性能,然而对于微塑料与有机污染物的相互作用方式仍较为缺乏。为了探究O_(3)老化聚对苯二甲酸乙二醇酯微塑料(PET-MPs)与甲基橙的相互影响,通过将微塑料暴露于臭氧中模拟了微塑料在自然环境中的老化过程,进而改变其物理化学性质,影响其对有机污染物的作用。结果表明,随着老化时间的增加微塑料表面更为粗糙,且存在不规则的孔隙,伴随着结晶度降低、亲水性增强、吸附量减少,微塑料对MO的吸附在24h内基本达到平衡,能够用一级动力学模型较好地拟合(R^(2)>0.98)。吸附等温线更符合Freundlich模型(R^(2)>0.94),属于多层吸附。与水分子之间的氢键作用力增强是导致PET对MO的吸附能力下降的主要原因,不过随着温度的升高,吸附能力也逐渐增强。这一研究结果对于进一步探索微塑料的环境影响提供了理论依据。

Microplastics have high adsorption to environmental pollutants,but the interaction between thetwo is not clear.In order to explore the interaction between O_(3) aging polyethylene terephthalate microplastics(PET-MPs)and methyl orange,the aging process of microplastics in the natural environment was simulated by exposing microplastics to ozone,and then its physical and chemical properties were changed to affect its effect on organic pollutants.The results showed that the surface of microplastics was rougher and rougher with the increase of the aging time,and there were irregular pores.With the decrease of crystallinity,the enhancement of hydrophilicity and the decrease of adsorption capacity,the adsorption of microplasticstoMO basically reached equilibrium within 24h,which could be well fitted by the first-order kinetic model(R^(2)>0.98).The adsorption isotherm was more in accord with the Freundlich model(R^(2)>0.94),which belonged to multi-layer adsorption.The enhancement of hydrogen bonding force between PET and water molecules was the main reason for the decrease of adsorption capacity of PET to MO.The adsorption capacity increased with the increase of temperature.The results of this research provided a theoretical basis for further exploring the environmental impact of microplastics.