TECHNICAL FEASIBILITY OF ANAEROBIC CO-DIGESTION OF SEWAGE-SLUDGE AND MUNICIPAL SOLID-WASTE

Experiments were conducted using one-litre anaerobic batch bioreactors operated mesophilically (37 degrees C) and fed a mixture of primary s ludge (RAW), thickened waste activated sludge (TWAS) and simulated org anic municipal solid waste (MSW). A mixture of 25% MSW and 75% sewage sludge (60% RAW, 40% TWAS) yielded the highest biogas production. Base d on biogas production, the most anaerobically biodegradable component s were the white paper and grass components of the MSW. The TWAS and t he newspaper components of the MSW were found to be the least biodegra dable components. Both particle size and total solids concentration of the feed had a significant impact on the performance of the process. Over the operating region studied, the optimal operating conditions in terms of biogas production and volatile solids removal were at small particle sizes (0.85 mm, the smallest studied) and high total solids c oncentrations (22.1%, the highest studied).