Sahdieieva O. Improvement of the composting technology of food component of the municipal solid waste

The dissertation is devoted to solving the problem of the ecological safety level increasing by introducing an advanced technology of the MSW food component composting. Since up to 40% of solid waste is classified as easily decomposable organic waste, removing this part of waste from landfills by composting and turning waste into secondary material resources will substantially reduce the environmental burden of actually and potentially planned landfills on the environment. The identification and assessment of ecological aspects of the functioning of landfills is carried out, the ecological danger formation’s mechanism under their influence is determined. The analysis and assessment of the environmental hazard level using the system of complex indicators characterizing the probability of occurrence and the ecological hazard degree is carried out. An algorithm for ecological safety management of landfill sites is developed, where the object of management is the waste morphological composition that is capable of methanogenesis and is the main source of greenhouse gas formation and emergence of an emergency situation. Emissions of greenhouse gases were assessed and methane formation volumes were determined on the landfill site. The degree of their reduction was estimated through the introduction of a composting technology of the MSW’s food part with the introduction of microbiological or mineral additives. In order to improve the composting technology of the MSW's food component, it is substantiated that the mineral or microbiological additives, introducing into the compost mixture, will lead to the activation of microbial activity in the initial stages of the process. During the experiment, the abiotic, biotic and maturity indices of the obtained compost were studied. It is proved that the process of maturation of the compost when adding the mineral additive is accelerated by 2.2 times under the thermophilic conditions and 1.4 times by the mesophilic ones, and the process of maturation of the compost when the microbiological additive is applied is accelerated by 3.3 and 2.1 times, respectively. The implementation of the improved technology of the MSW's food component's composting will significantly reduce the amount of stored waste, greenhouse gas emissions, including methane, and will obtain high quality organo-mineral fertilizers as a final product of processing.