ADSORPTION CHARACTERISTICS OF MICROPOLLUTANTS ON MICROPLASTICS BY FOCUSING ON THEIR DIAMETERS IN WATER ENVIRONMENT

Abstract

 Recently, a new exposure pathway of micropollutants via Microplastics (MPs) to aquatic organisms have been a great concern. Main objective of this study was to understand adsorption characteristics of perfluoroalkyl acids (PFAAs), polycyclic aromatic hydrocarbons (PAHs) and their halogenated compounds (X-PAHs) in water environment by focusing on the diameters of MPs. Adsorption bach experiments with standard substances of MPs were conducted. Field surveys were conducted in Lake Biwa and Osaka bay from Oct. to Nov. 2017 in order to analyze 15 PFAAs, 16 PAHs, 11 X-PAHs on adsorbed MPs in surface water. It was shown that MPs in water environment with smaller diameter tended to adsorb more PFAAs, PAHs, X-PAHs. It was assumed that micropollutants were adsorbed more to MPs than to suspended solids when their diameters were in the range of several tens of μm. In addition, it was suspected that more PFAAs and PAHs were adsorbed to MPs when surface areas of MPs were increased by the effect of physical and/or chemical reactions in the water environment.