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Wastewater neutralization process of enterprises producing phosphorus-containing mineral fertilizers with the recycle of sludge to the head of the process as a promising resource-saving technology is considered. The prospects of the technology are to decrease the volume of sludge stored at the landfill and to reduce the content of phosphorus and fluorine in it. The influence of the recycling coefficient on the emerging sludge is analyzed.

This paper presents the results of the study of initial pedogenesis on phosphogypsum dump rocks under dry steppe bioclimatic conditions (Balakovo, Saratov Region, Russia). It was shown that a soil crust about 3 cm thick was formed at the dump surface as a result of natural pedogenic processes over a period of 20-30 years. Such soil crusts act to cement the surface and protect the dump material from deflation and water erosion. The crust was shown to consist of two parts that can be distinguished by morphological features: an upper part (about 2 cm thick) of a more firmly bound material more grey in colour and a lower part (about 1 cm thick) with a looser consistency and lighter colour. The structural organisation is primarily determined by the presence of live roots of grasses and mosses, which is characteristic of a biogenic crust. The two parts of the crust were characterized at both macro- and micro-scales, by use of thin sections and tomographic imagery. The presence of humification features and porosity observed within the crust allowed for the diagnostics of initial pedogenesis.

Production of phosphorus-containing fertilizers is related with the problem of reclamation of phosphogypsum dumps formed during the processing of Apatite-nepheline ore. In this regard, some attention should be paid to biological remediation as the most effective ecological method. Biological reclamation is one of the ways to protect the environment in the formation of phosphogypsum dumps. In this article, we propose a method for assessing the effectiveness of remediation using phyto monitoring using satellite data, which are used as the results of remote sensing. The proposed method allows estimating the volume and state of biomass of plants forming vegetation cover on the surface of man-made massif.