Nano- and microplastic analysis: Focus on their occurrence in freshwater ecosystems and remediation technologies

Abstract

Plastic pollution is a global problem since 2016 when its production reached 322 million tonnes, excluding fibers. Daily discharges of microplastics (MPs, defined as <5 mm in size) are estimated in the range of 50,000 up to 15 million particles, whereas no information on nanoplastic (NP, <100 nm) release is available yet. Different processes further degraded these materials producing more MPs and NPs. This review attempts to fill the void of information on the state-of-art analysis of MPs and NPs (recently identified as emerging contaminants) and provides a critical overview on modern instrumentation, newly developed workflows, and promising techniques for their characterization (Raman and FT-IR spectroscopies and microscopies, pyrolysis and thermal desorption gas chromatography, imaging techniques, etc.). Available analytical methods, validation as well as applications with cells have been taken into account. MP and NP sampling, identification, and characterization are discussed. Finally, recent applications to establish their occurrence in freshwater ecosystems and the effectiveness of the proposed remediation technologies are considered.