METHANE FERMENTATION OF PIG STOCK

Pig farms are a significant source of environmental pollution, since their activity is accompanied by the generation of large volumes of concentrated waste and wastewater. Particularly dangerous for the environment are sewage effluents, which are characterized by a high content of contaminants. Therefore, it is urgent to solve the problem of biotechnological utilization of liquid waste of pig farms, which, through the use of biogas, would not only improve the local environmental situation, but would also be economically viable. The purpose of the work is to study modern methods of ecological biotechnology, namely methane fermentation of manure waste from pig farms. This will solve the problem of wastewater disposal, while ensuring the production of a significant amount of biogas and of fermented biomass, which is a fertilizer. The authors determined that the slurry is subjected to continuous methane fermentation at a temperature of 45°C. Methane digestion of the substrate with a moisture content of 96.1; 93.8 and 91.12% were carried out at the dilution rates of 4.2·10-3, 5.0·10-3, 6.3·10-3 h-1 . The amount of biogas synthesized per unit of dry matter loaded (DMloaded) depends largely on concentration and dilution rate. The maximum production of biogas (220 dm3 /kg DMloaded) was recorded at a dilution rate of 4.2·10-3 h-1 . The methane content of biogas was 70-78% depending on the substrate concentration and process conditions, which testifies to its full use as fuel. The pH of the culture fluid ranged from 7.5 to 8.5 and did not require artificial regulation. Reducing the intensity of the process of purification by chemical oxygen demand (COD) has a direct dependence on the substrate moisture and reversed the speed of dilution. The highest purification efficiency (88.92%) was achieved when the substrate was digested with maximum humidity (96.1%) and the lowest dilution rate (4.2·10-3 h-1). The following forms of vitamins of the cobalamin group have been found in fermented biomass: B12 and factor III, which are active forms of the vitamin, and factor B is inactive, with a large number of them. The total content of vitamins largely depends on the characteristics of the substrate (type and concentration of pollutants), fermentation parameters, etc. and ranges from 21.23 to 43.74 mkg/g DM