MICROPLASTICS IN THE “URBANIZED CATCHMENT – RIVER – SEA” SYSTEM: SOURCES AND MIGRATION PATHWAYS IN THE SOUTH OF RUSSIA

Abstract

A comprehensive analysis of the basin migration of microplastics (MP), with a size range of 0.1–5 mm, in the “urbanized catchment – river – sea” system for the south of the European part of Russia has been performed. Based on the expedition data from 2023–2025 with NOAA processing and the use of Raman spectroscopy and pyrolytic gas chromatography with mass spectrometry (Pyr–GC–MS), as well as taking into account the granulometric analysis of bottom sediments, the quantitative and qualitative characteristics of MP have been established. The content of the study objects was as follows: in wastewater Rostov-on-Don from 3 to 19 units/m3 , waters of the Lower Don 94 units/m3, bottom sediments of the Sea of Azov 61 micrograms/g, in benthic organisms (Anadara kagoshimensis) 4.5 units./individual. No significant difference in morphotypes was found – transparent fibers predominate in all matrices (length parameters: mode range 0.3–0.7 mm, median 0.8–1.2. average value 1–1.5). It is shown that during the transition from the river to the sea, there is a decrease in the amount of suspended MP and its accumulation in finely dispersed clay silts. The work is based on the methodologies and ideas laid down by the I. P. Chubarenko scientific school.