TREATMENT OF LIQUID AND SOLID MUNICIPAL WASTE IN ANAEROBIC DIGESTION OPTIMIZED FOR BIOGAS PRODUCTION

Organic waste accrues as liquid and solid material which requires different treatment in anaerobic digestion plants. Food leftovers, such as kitchen waste have high energy potential but are low in structural compounds and the biogas-forming process is often impaired by accumulation of volatile organic acids. The effect of additional biofilm carriers on process stability and biogas yield was tested in two of four parallel operating experimental digesters of 9L volume. It has been found that slight amendment of plant structures for biofilm formation significantly stabilised methane production compared to control digesters. Anaerobic treatment of municipal solid waste (MSW) can be done in garage-shaped fermentation containers. The efficiency of the degradation of volatile solids (VS) and potential methane yield was evaluated using fermentation bags in a full-scale biogas plant. The results showed levels of VS degradation of the studied MSW above 50 %. Both experimental approaches have demonstrated that organic waste can be a valuable source of regenerative energy when appropriate technology is applied.