No abstract

This paper reports an analysis of current issues related to storing solid household waste, and, specifically, the problem of environmental pollution when unsorted solid household waste (SHW) is ignited. A technology has been developed to improve environmental safety and ensure a reduction in the anthropogenic load on the atmosphere, hydrosphere, and lithosphere in the event of fires at the sites of solid waste storage. The operation of the proposed equipment, taking into consideration all the provided operating modes and additional options, is energy-saving and automated (or semi-automatic), which makes it especially relevant under modern conditions. The technology significantly improves the efficiency of the processes to eliminate the ignition of SHW and localize their environmental consequences for the territories adjacent to landfills. Laboratory tests were carried out, which proved the effectiveness of practical application for the designed equipment of a new environmentally active adsorption mixture for the purpose of cleaning the waste filtrate, as well as its use for the formation of an anti-filtration screen in the mound of SHW. Experiments have shown that the tested sample of the aqueous suspension of the proposed environmentally active mixture adsorbs calcium (by 92 %), overall iron (by 91 %), overall phosphorus (by 75 %), zinc (by 31 %), and ammonium (by 19 %). This leads to a decrease in the overall toxicity of the solution and indicates the possibility of improving the environmental safety of waste fires when operating the proposed technical solution by purifying the filtrate released during fires in landfills. The reported results, specifically, the technology for localizing the environmental consequences of uncontrolled waste ignition could be used in the process of modernizing the technical support for sanitary treatment schemes in urban areas.

The object of this study is the operating parameters of the anaerobic digestion unit. The study aims to increase the potential of biogas production. The task to select the optimal parameters of the working process of anaerobic digestion has been solved. A model of cumulative biogas and methane output in the process of anaerobic waste digestion has been constructed, which is conceptualized using the method of artificial neural network. The model is built on the basis of 11 process-related variables, such as hydraulic retention time, pH, operating temperature, etc. The plant parameters, leading to the highest volume of biogas production, were selected. It was determined that the optimal amount of biogas can be brought to 90 %, which exceeds the maximum value obtained from factory records by 12.6 % to 700 m3/t. Working conditions that led to optimal methane production were defined as the temperature of 39 °C, the total solids of 4.5 %, the organic percentage of 97.8 %, and pH 8.0. It was found that biogas production is the highest at temperature within the thermophilic range while the local maximum is achieved in the mesophilic temperature range. The model built serves to determine the optimal operating parameters for maximum biogas production and could be used to optimize biogas production productivity using limited experimental data. The model also makes it possible to predict the performance of anaerobic digestion under untested conditions. It is possible to practically use the developed biogas production model when monitoring the operation of the anaerobic digestion unit, to increase the efficiency of the process, and when adjusting the working conditions of the methane tank

No abstract

No abstract