ACCUMULATION AND DEGRADATION OF MACRO-, MESO- AND MICRO- PLASTICS ON RIVER BANKS OF ARAKAWA RIVER

Abstract

 In order to clarify the transport process of plastic debris from land, the accumulation of macro-, meso- and micro-plastic debris on river banks were investigated in the Arakawa River. The plastic debris were accumulated at the downstream site comparing with the upstream sites. The amounts of meso- and micro-plastics on the higher river bank was more than that near the river edge, indicating that the degradation of plastic debris could progress on the river bank. In addition, the degradation level of plastic debris collected from the river banks was understood by measuring a ratio of absorbance at carbonyl and methylene groups. The degradation level was high in order of micro-, meso- and macro-plastics, indicating that the degradation level of smaller plastic debris was high.