Large Scale Microplastic Fibre Analysis in Wastewater: A Comprehensive Review and Recommendations

Abstract Purpose of Review This review provides a critical analysis of current and emerging methods for identifying and quantifying microplastic fibres (MPF) in wastewater, covering all key steps of sample collection, pretreatment, and analytical analysis. There are currently no universally accepted standards for collecting and analysing MPF. This review aims to provide new insights to develop appropriate processes for collecting and analysing MPF in wastewater through a critical analysis of the literature. Recent Findings Previous studies have used non-selective grab sampling and stacked sieving apparatuses to collect and/or sort microplastics, but very few have been specifically applied to MPF. Hydrogen peroxide (H 2 O 2 ) digestion is the most widely used for sample preparation prior to MPF analysis. MPF quantification by manual counting under an optical microscope is possible but is inefficient and unable to meet the required level of accuracy. Either micro–Fourier Transport Infrared (µFTIR) or µ-Raman is suitable for polymer identification. They each have distinctive reported strengths and weaknesses, and µFTIR is more appropriate for MPF analysis. Summary Fast and scalable analysis can be achieved with grab sampling for collection, H 2 O 2 digestion for pretreatment, filtration using glass fibre or alumina oxide membranes, and then microscopic imaging with fluorene tagging for automated counting. Transmittance μFTIR is the most appropriate tool for polymer identification. Density separation, extensive sample digestion, manual counting, and Raman spectroscopy are not required or incompatible for MPF analysis.