This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.
Contaminant release from aged microplastic
Recycled plastic granules of HDPE, PVC and PS the size of microplastics were exposed to artificial ageing conditions (2000 h; photo-oxidative and thermo-oxidative) to simulate their fate outdoors. Their potential to leach into water in the course of the ageing process was investigated using column percolation tests. Ageing-related changes on the surface of the material were characterized by IR measurements indicating oxidation reactions with the formation of new adsorption bands (C=O; C-O and OH), especially in the case of photo-oxidative ageing. These findings were confirmed by the identification of leachable organic compounds. Leaching of TOC, Cl, Ca, Cu and Zn is clearly affected by changes due to ageing, and their release is increased after photo-oxidative ageing. In general, exposure to photo-oxidative conditions exhibits a greater influence on ageing and thus on leaching and seems to be the more important mechanism for the ageing of microplastic in the environment. Comparison with the total content of inorganic species revealed that, for most elements, less than 3% of the total content is released after 2000 h of photo-oxidative ageing.
EN17064 Accepted 06 July 2017
© CSIRO 2017