Microplastics in solid matrices of the environment

Microplastics, plastic particles of 5 mm-1 nm in size, are now widespread across different ecosystems. The increasing amount of microplastic contamination of aquatic and terrestrial environments requires the development of standardized methods for their separation and analysis. One of the main vectors of microplastic input to terrestrial ecosystems is through sewage sludge. The sludge is recycled for fertilization and reclamation due to its high organic matter content. Scientists have already been able to quantify and identify a range of microplastics in sewage sludge of different sizes, polymer types, shapes, etc. This thesis focuses on the optimization of existing methodologies to extract microplastics from solid environmental samples and their subsequent qualitative and quantitative analysis. The steps required for sample pre-treatment prior to analysis, namely reduction in organic matter content by the Fenton reaction process and density-based separation of microplastics by flotation in saturated NaI solution (1.8 g/cm3 ) using centrifugation, were optimized. Microplastics in size fractions of 20-40 μm and 150-300 μm were fabricated and introduced into flotation and total recovery experiments of the methodology to determine the recovery. Fluorescence microscopy was chosen for quantitative...