Rare-Earth Elements in the Atmospheric Precipitation of the City of Blagoveshchensk

Аннотация

The mineral composition, distribution and fractionation of rare-earth elements in dissolved and suspended forms (solid residue) of atmospheric precipitation were studied by analyzing the snow sampled over urbanized territory by the example of the city of Blagoveschensk. Electron-microscopic studies revealed the own minerals of rare-earth elements in dust aerosols. It is shown that the main sources of the atmospheric pollution by rare-earth elements were emissions of TPP (heat and power plants) and boiler houses. Contrasting geochemical anomalies of rare-earth elements were found in the snow cover of the city. The REE concentrations in the solid phase of snow are few orders of magnitude higher than those of the liquid phase. The snow solid phase provides insight into the REE behavior, because it directly reflects the impact of different anthropogenic sources. The characteristic feature of the REE distribution in the solid residue of snow is their LREE enrichment relative to MREE and HREE. The average HREE content is 10% of total REE. In the snow water–solid phase system, most samples show weak fractionation between LREE and HREE owing to the low total mineralization of the snow liquid phase and the small content of organic matter.