Temporal and spatial variations of microlitter (ML) concentrations in Gothenburg were measured by sampling surface water. ML was divided into three main categories; microplastics (MP), fibers (F) and other anthropogenic particles (OA). Samples were collected using a pump installed with 300 μm and 50 μm stainless mesh filters, during three separate field sampling campaigns during the fall and early winter of 2017. Samples were treated with H2O2 digestion for removing organic material. Microlitter were then visually counted and categorized for all samples under light microscope. In the 300 μm fraction, F was most prevalent at 84.6 %, MP at 12.9 % and OA at 2.5 %. Concentrations of MP varied from 0.1 to 22 MP/m3 in the 300 μm size fraction and from 0 to 81 MP/m3 in the 50 μm size fraction. MP concentrations collected on the 50 μm size filter were higher compared to the 300 μm size filter in all but two samples. MP from the 300 μm size fraction was further subcategorized as particle/fragment (71 %), film (14 %), filament (9 %), expanded cellstructure (3 %) and pellets (3 %). MP concentrations found in Gothenburg surface water are comparable to what has been found in other urban cities of Sweden, but higher compared to studies measuring MP concentrations along the Swedish east, west and southern coastline. The polymeric structure of MP particles from the 300 μm size fraction was analyzed with Attenuated Total Reflection Fourier Transform IR (ATR-FTIR) and were identified as polyethylene (46.5 %), polypropylene (17.2 %), polystyrene (9.0 %), polyethylene terephthalate (3.1 %), polyamide (1.2 %), and 23 % were unmatched. Possible correlating factors such as precipitation and ML concentrations were explored but the data was insufficient for any decisive conclusions to be made. Flow rate, the volume of water passing per time unit in the water course was shown to have an inverse correlation with concentration. Large temporal variation was observed at most of the sampling sites. It is not possible to pin point or quantify any particular source of ML pollution with this data, however it can be stated that ML’s from various urban sources indeed do contribute to ML pollution, and that the pollution from these sources vary over time based on factors that are not yet known.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:oru-76599 |
| Date | January 2019 |
| Creators | Vigren, David |
| Publisher | Örebro universitet, Institutionen för naturvetenskap och teknik |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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