Innovative technologies secondary use of processed active source

Abstract

The article presents the ecological problems of utilization of spent activated sludge, which is a waste after biological treatment of wastewater and ways of their solution. A literature review devoted to modern methods of recycling and recycling of spent activated sludge is presented. The methods of composting of spent activated sludge, advantages and disadvantages of field composting of spent activated sludge are considered in detail. Ways of utilization of spent activated sludge in foreign countries are considered. It has been shown that, since the time of the USSR, spent activated sludge was used as a source of mineral fertilizers. The technologies of obtaining mineral fertilizers from spent activated sludge are described, their advantages and disadvantages are shown. Materials for obtaining protein-vitamin product from spent activated sludge, which can be used for feeding animals, fish and birds, have been studied. The technology of obtaining a microbial protein from spent activated sludge is described. The works in which the spent activated sludge is used for reclamation of slurry grouting are presented. The publications devoted to the production of fuel from spent activated sludge, molded into briquettes, are considered. Presented are the works of Perm scientists who developed the technology of obtaining from spent activated sludge biosorbents used for soil cleaning during oil and oil product spills. In the experimental part, physicochemical studies of the spent activated sludge from the silt areas were carried out by the authors and the gross composition of the elements was determined, which showed that the spent activated sludge is characterized by high toxicity due to the presence of heavy metal impurities. Thermal analysis was carried out, which allowed to determine the temperature range of decomposition of organic matter of spent activated sludge. Based on physical and chemical studies, a technology for neutralizing spent activated sludge was proposed. This technology includes detoxification of spent activated sludge with calcium-containing reagents, to remove toxic elements (heavy metal ions) followed by heat treatment. Thermal treatment is carried out under conditions of minimal access of oxygen to remove pathogenic microorganisms, organic contaminants and formation of active carbon. The obtained material was used as an adsorbent for cleaning oil-contaminated wastewaters and obtaining complex fertilizers that allow intensifying the processes of phytoremediation of soils from oil products.