Microplastics in urban stormwater systems of Western Sydney

Abstract

This study assessed the extent of microplastic (MP) pollution in the stormwater catchments of Western Sydney. Studies on microplastics in Australian stormwater systems and the lack of generally accepted methods for sample collection and the isolation and quantification of microplastics, were identified as opportunities for exploration. One of the objectives of this study was to identify and develop an acceptable method for separating microplastics from water samples. A novel procedure was developed to collect microplastics by filtering stormwater using a purpose-built single sieve (48.5 µm) mini-filtering device and cascade filtration setup, which included four steel filters with pore sizes of 48.5, 170, 2500 and 5000 µm. Additionally, the six most commonly used microplastic separation methods were selected to assess their organic matter degradation efficiency and polymer degradation potential. This research also presents the first results regarding microplastics pollution in Western Sydney stormwater catchments. Sample collection and analysis were carried out in two steps: preliminary sampling and secondary sampling. Preliminary sampling was carried out in the urban lake of Woodcroft using the mini-filtration device to test the practicality of the pre-identified procedures. Woodcroft and Wattle Grove were selected as the study areas for secondary sampling. Similar microplastics concentrations were observed in secondary sampling for both sites. From a comparison of the data obtained in this study with those in the literature, it was apparent that the stormwater originating from these two urban catchments was considerably contaminated with microplastics. This was attributed to anthropogenic activities in urban areas. Microplastic particles in stormwater can adversely impact aquatic life present in the receiving water bodies. Also, the presence of microplastics could suggest the presence of nanoplastics in urban stormwater. These findings have implications for urban stormwater management and highlight the need for comprehensive and in-depth studies to evaluate micro- and nanoplastics in the inland water bodies of Australia.

Date of Award	2021
Original language	English