| dc.description.abstract | Microplastic pollution is of growing concern and is today one of the most important problems of the Earth. When microplastic is release into the environment it can have major impact on both humans and other living being. Microplastic have been found in all the natural environments, including oceans and the atmosphere (Ferrero, et al. 2022). This project research likes to present the abundance of microplastic at two different beaches and one public school and comment on the types of plastic within the samples. However, the main objective is to present a technic for sampling, separation, and identification via Raman.
In this study, selective and bulk sampling was used for the sampling and density separation for the separation process. The methodology was optimized for the purpose of this study and different density fluids were used to develop the best possible method to be used. With comparison to an experienced Raman laboratory, where we measured all standards and samples, we could define the ideal analytical set up for plastic research with Raman at UiS: 633 nm laser, 1 s of exposure time, 30 of accumulations fixed at 10 %.
Sampling has been carried out at two popular beaches in Rogaland, Sola (sample set SO), Bore (sample set BO) and in a sandbox of a public school (sample set SS). Results showed similar mineralogical composition in all the samples. However, the SS samples contained a significant higher abundance of chlorite and mica and was poorly sorted. In total the SO sample, the best sorted, has the higher abundance of microplastic, while the SS samples has the highest abundance of microplastic particles smaller than 1000 µm. The BO sample also had a lot of microplastic nurdles at its surface while no nurdles were observed at SO or SS.
This study only concentrated on material larger than 32 µm as this already had been sufficient material for this thesis project. Samples at the same location from 30 cm depth show much less or were even barren in regard of microplastic > 32 µm. Significant drainage could for that size of plastic not be observed. Maybe in smaller fraction such an effect is possible. The plastic identified were mostly larger than 1000 µm in both, SO and BO samples but only on the surfaces. Still, contamination of deeper parts of the sediments took still not place for large plastic particles. Generally, SS contained as well smaller samples but was less contaminated by plastic then the beach samples. The main occurring plastic types in all three samples has been polypropylene, polyethylene and poly (ethylene-vinyl acetate).
Suggestion for further study is to investigate in sediments the grain size smaller than 10 µm to target plastic fibres between 5-10 µm. Nevertheless, the defines methodological set up can also be used for that fraction at UiS. | |
