Percolating-Bed Anaerobic Composting of Food Waste

Technologies which contribute to sustainable agricultural productivity while conserving air, water, soil and energy resources are desperately needed. Nutrients, especially nitrogen, and energy contained in wastes from agricultural products need to be returned to farming operations to improve sustainability. Policies which promote recycling of municipal solid waste streams are creating new market opportunities for alternative utilization of wastes to meet mandated recycling goals. Many states are restricting the disposal of degradable wastes in landfills. The alternatives for disposition of source separated food wastes are re-feeding and composting. Since this waste is putrescible, re-feeding is not normally feasible. Food waste has such a high moisture content (>80%) that aerobic composting requires extensive use of bulking agents and aeration efforts to reduce odor and ensure an adequate oxygen supply. Also aerobic composting results in loss of nitrogen (>50%). This project will explore the feasibility of using percolating-bed anaerobic composting (PBAC) technology to process source separated food waste into a liquid fertilizer, a soil amendment and a fuel source.