Известия Томского политехнического университета: Инжиниринг георесурсов (Mar 2022)
TECHNOGENIC MICROSPHERES IN SURFACE SEDIMENTS OF URBAN AREAS
Abstract
The relevance of the research is caused by the need to study the anthropogenic component of solid surface sediment in a modern city. Technogenic particles, including magnetic and silicate microspheres, can be a source of heavy metals, accumulated in sediments and affect the geochemical background of the environment. The main aim of the research is to select and study the microspheres of various genesis in solid surface deposits of urbanized environment. Object: microspheres taken in samples of urban surface sediments from 11 cities of Russia: Ufa, Perm, Tyumen, Chelyabinsk, Nizhny Tagil, Magnitogorsk, Nizhny Novgorod, Rostov-on-Don, Murmansk, Yekaterinburg, Pervouralsk; chemical composition and surface morphology of microspheres of various elemental composition and genesis. Materials and methods. The investigated microspheres taken from samples of urban surface sediments, were divided into fractions by particle size. We studied fractions of 100–250 and 250–1000 µm, as well as samples that were not prepared in advance using automobile air filters. Microspheres were collected by visual diagnostic methods. Magnetic microspheres were selected by magnetic separation. All selected microspheres were examined using scanning electron microscopy. Results. The selected microspheres divided into 4 classes according to their chemical composition: ferrous, silicate-ferruginous, acidic fly ash and base fly ash. Clarification of the chemical composition allowed making an assumption of the possible genesis of microspheres. In addition to petrogenic elements, microspheres contain heavy metals (Cr, V, Mn, Co, Ni, Cu, Zn, Pb). The correlation of Fe/O and changes in the morphology of the particle surface for iron-containing microspheres is considered. Fly ash classified according to the predominance of one or another oxide in the composition. Conclusions. The data indicate that microspheres are part of the technogenic component of sediment in urban environment. Despite their were low content in sediments, they can be a source of toxic elements and affect the change in the geochemical background of urban areas.
Keywords
