Study on the recovery potential of nitrogen and phosphorus and GHG Emissions from Biomass Waste Management Systems in Japan

Abstract

This study estimated the recovery potential of nitrogen (N) and phosphorus (P) contained in different types of biomass waste (food waste, sewage sludge, manure waste) in Japan under the assumption of recycling total biomass waste through composting and anaerobic digestion. Indirect and direct GHG emissions generated from the recycling process, excluding transportation, were also estimated. Firstly, the N and P flow and GHG emission from the current solid waste management system was calculated. About 90% of N and P were reduced to N₂ and stocked in the landfill after incineration. Under the assumption of recycling, the recovered amount of N and P from the codigestion of food waste and sewage sludge through anaerobic digestion was about five times higher than the current situation, with 20% less GHG emission. The recovered N and P from manure waste treatment were already enough for the amount of chemical fertilizer demand but showed a 200% of a significant reduction in GHG emissions in the scenario of anaerobic digestion. Further consideration of regional properties in appropriate treatment and GHG emissions from transportation is required.