Microplastic fragments into nanoplastics (NPs) and microplastics (MPs) and is present in every environmental compartment. however, the weathering process and fragmentation rate are still poorly understood. To address this, we quantified the size distribution of produced NP and SMP particles on the surface of virgin- and additive-containing (PP) sheet. We achieved this by exposing them to photooxidation with water in a simulated sunlight chamber, followed by mechanical abrasion. The fragmentation rate of PP and PPa (additive-containing PP) was similar following 176 days of simulated sunlight exposure with subsequent mechanical abrasion (corresponding to 2.7 years of exposure in an outdoor environment in the Republic of Korea). However, considering the quadratic regression graphs for PP, which display the relationship between total particles produced and exposure duration, it is possible that the fragmentation rate of PP could be faster than PPa after a certain point of sunlight exposure duration (i.e., after 2.7 years). We also observed that mechanical stress from vortexing played a significant role in the production of MPs, but a smaller role in the production of NPs. Fragmented particle sizes produced through photooxidation and mechanical stress followed a power law distribution, with a scaling exponent of α = 2.87 ± 0.15, which was similar to a three-dimensional fragmentation pattern. Future studies with longer experimental periods are needed to precisely quantify the differences in fragmentation rates of PP and PPa under different environmental conditions.
Primary Presenter: Young Kyoung Song, CHONNAM NATIONAL UNIVERSITY (songyk1621@gmail.com)
Authors:
Sang Hee Hong, Korea Institute of Ocean Science and Technology ()
Soeun Eo, Korea Institute of Ocean Science and Technology ()
Won Joon Shim, Korea Institute of Ocean Science and Technology ()
Fragmentation of virgin- and additive-containing polypropylene under simulated-sunlight exposure and mechanical abrasion
Category
Scientific Sessions > SS024 Down the Drain and Down the River: The Transport, Fate and Impact of Micro- and Nanoplastic on Their Way to the Oceans
Description
Time: 06:30 PM
Date: 7/6/2023
Room: Mezzanine