Influence of Urban Land Use on the Accumulation of Microplastics in Urban Water Bodies Add supervisors Supervisors: Vincent Pettigrove Dave Sharley Kallie Townsend Hsuan-Cheng Lu

Microplastics Persistence and durability Increasing in plastic waste globally. Occurrence has been reported globally. Ingestion by organisms in environment Absorption of persistent bioaccumulative and toxic compounds (PBTs), such as organic pollutants and metals. Why microplastics are important Brief introduction of the history Effect on ecosystems

Where do microplastics come from? Primary Primary microplastics refer to those are in the original form when found, such as microbeads used in many cosmetics and personal cleansers (Napper et al. 2015), virgin resin pellets for plastic manufacture, fibres in textiles (Fendall and Sewell. 2009), and industrial scrubbers used for abrasive blast cleaning (Derraik 2002).

Where do microplastics come from? Secondary On the other hand, secondary microplastics refer to those derived from the breakdown of large plastic debris due to photo degradation and UV radiation (Ryan et al. 2009).

Size classification Minimum size ? however, there is no consensus about the actual size range of microplastics. At first, researchers defined them as any plastics with diameter less than 5 mm. but the application of 1 mm has gradually increased because it is more close to the concept “micro”. So far, microplastics are only defined their maximum size, but how about the minimum size? The minimum size of microplastics mainly depends on the research objective, sampling and processing methods applied.

Marine Estuary Freshwater waterways What have been done Marine Estuary Freshwater waterways Sediment or surface water Urban water bodies, such as wetlands?

Microplastics in Constructed Wetlands Is there any pollution? What types of microplastics present? What are the main urban land use generating the pollution? Lots of macroinvertebrates live in the sediment and they might expose to the contamination of microplastics What are the sources of microplastics in urban wetlands? Are they produced by residential, industrial etc?

Aims To develop a standard technique to extract microplastics from freshwater environment. To investigate the occurrence and sources of microplastics in urban environments.

Constructed Wetlands key component of stormwater management strategies Improve water quality - ↓nitrogen, enhance landscape and ecological values, socially acceptable

Sediment classification: very fine sand Industrial Site Sediment classification: very fine sand

Sediment classification: very fine sand Residential Site Sediment classification: very fine sand

Sediment classification: coarse silt Mixture Site Sediment classification: coarse silt

How to extract microplastics from samples?

Types of plastics and high density solution Abbreviation Density (g/cm3) Polypropylene Polyethylene PP 0.85-0.94 PE 0.91-0.96 Ethylene vinyl acetate EVA 0.92-0.95 Polystyrene PS 0.96-1.04 Acrylonitrile butadiene styrene ABS 1.06-1.08 Acrylic   1.09-1.20 Polyester PES 1.1-1.4 Polyamide PA 1.12-1.15 Poly methyl acrylate PMA 1.17-1.20 Polyurethane PU 1.20 Sodium chloride NaCl Polyvinyl alcohol PVA 1.19-1.31 Polycarbonate PC 1.2-1.22 Alkyd 1.24-2.10 Polyvinylchloride PVC 1.35-.45 Polyethylene terephthalate PET 1.37-1.45 Polyoxymethylene POM 1.41-1.42 Zinc chloride ZnCl2 1.5-1.7 Sodium iodide NaI 1.6-1.8

Pilot Study: Pre-cleaning step

Pilot Study: Comparison between high density salt solution Each type of plastic were spiked with ten pieces. Density Polypropylene (PP) 0.85-0.94 Polyethylene (PE) 0.91-0.96 Acrylic 1.09-1.20 Sodium chloride 1.2 Polyvinylchloride (PVC) 1.35-1.45 Polyethylene terephthalate (PET) 1.37-1.45 Zinc chloride 1.5-1.7 Sodium chloride Zinc chloride PP 6 8 10 9 PE Acrylic 2 7 PVC 4 PET 1

Methods Sediment collection from study sites. Sieving through 1 mm and 35 um mesh. Density separation (ZnCl2 , d = 1.5 - 1.7 g/m3). Visual examination under microscope.

Preliminary Results 1 mm Site: Avoca Street Retarding Basin Predominant Land Use: Commercial

Preliminary Results 500 um Site: Cala Street Ponds Predominant Land Use: Industrial

Preliminary Results Site: Albert Park Lake Predominant Land Use: Open Space 1mm

Future work To refine new technique to extract microplastics from freshwater sediment. To categorize microplastics, for example colors and size from 20 wetlands. To investigate the spatial distribution of microplastics in wetland sediment in relation to catchment land use.

Acknowledgement I wish to thank Simon Sharp, Steve Marshall, Pat Bonney for assistance with this project Thank you for Listening Hsuan-Cheng Lu hsuanchengl@student.unimelb.edu.au

Reference Claessens, M., Van Cauwenberghe, L., Vandegehuchte, M.B., Janssen, C.R., 2013. New techniques for the detection of microplastics in sediments and field collected organisms. Mar Pollut Bull. 70, 227–233. Hidalgo-Ruz, V., Gutow, L., Thompson, R.C., Thiel, M., 2012. Microplastics in the marine environment: a review of the methods used for identification and quantification. Environ. Sci. Technol. 46, 3060-3075.