Shynkarchuk М. Biotechnology of biogas production from fatty raw materials. – Qualifying scientific work on the rights of manuscript.
Thesis for candidate of Doctor of Philosophy the degree in the specialty 162 Biotechnology and Bioengineering. – National Technical University of Ukraine «Igor Sikorsky Kyiv Polytechnic Institute», Ministry of Education and Science of Ukraine, Kyiv, 2020.
Today, the leather industry is one of the most highly polluting and toxic industries due to a wide range of industry waste: organic (mist, fats, wool, blood) and chemical contaminants (chromium, sulfur, chloride, acids, alkalis, antiseptics). Тo date, there is a search and implementation of technologies for "greening" leather production.
Therefore, the urgent task for the leather industry is the processing of fat waste from energy sources and fertilizers.
Also, the issue of sewage treatment containing antibiotics remains unresolved and urgent. The efficiency of anaerobic method of water purification using the antibiotic-adapted association of microorganisms is substantiated and experimentally proved in the work.
The purpose of the work is to substantiate and develop the technological basis of biotechnological solutions for the processing of fat-containing waste products of leather production into biogas.
To achieve this goal it was necessary to solve the following problems:
to establish rational parameters of the process of anaerobic digestion of fat-containing waste of leather production in laboratory conditions;
to determine the rational ratio of fat-containing raw materials: cosubstrate for the process of biogas production and the content of methane in it for different types of cosubstrates;
adapt the anaerobic association of microorganisms to antibiotics and identify the types of methanogens that survive under such conditions;
to investigate the process of biogas production with the use of an antibiotic-adapted microorganism association;
to determine rational concentrations of the liquid and solid fraction of the degenerate substrate for introduction into the soil during cultivation of agricultural plants;
to develop technological and apparatus schemes for processing of fat-containing production wastes, which are received in the process of preparation of raw materials for tanning; and to develop recommendations on the feasibility of using biogas from fat-containing raw materials for processing of non-tanning waste of the enterprise.
The object of the research is biotechnology for the production of biogas from fat-containing waste from leather production.
The subject of research is the parameters of biogas production in the co-fermentation of fatty waste production of leather.
Research methods: physicochemical methods (pH-metry, etc.), gravimetric method, gas chromatography, molecular biology methods (DNA isolation, PCR, sequencing), methods of spectrophotometry, bioinformatic methods, methods of graph theory (MSExcel, AutoCAD).
The following scientific results were obtained for the first time in the dissertation:
determined the dependence of methane formation on the component composition of the fat-containing waste of leather production;
determined the dependence of biogas production on the component composition of cosubstrates (litter, corn waste, apple pulp) during the co-fermentation of fatty waste;
identified the types of methanogens present in the anaerobic association, adapted to high concentrations of norfloxacin and tetracycline, by DNA sequencing of microorganisms, enabling the enrichment of the microbial association with these species to increase biogas output and methane content;
substantiated the rational conditions of the process of fermentation of fatty raw materials at high concentrations of salts and antibiotics, which makes it possible to create technology for the processing of fatty waste products of the leather industry;
shown the possibility of using solid and liquid waste of digested fatty raw materials as fertilizer.
The practical significance of dissertation is to solve the problem of utilization of fatty waste of leather production with the biogas production.
Сosubstrates that can be used to provide a process for the digestion of fatty raw materials by nitrogen and trace elements to enhance biogas yield have been identified. Established rational technological parameters of digestion of fat-containing waste allow obtaining biogas with a concentration of methane up to 72%, which allows to increase the energy efficiency of tanneries, to reduce anthropogenic impact on the environment and to reduce the cost of production.
Keywords: biogas, methane, anaerobic digestion, fat-containing waste, co-fermentation, litter, antibiotics, norfloxacin, tetracycline, digestat.
