3rd International Congress on Sustainability Science & Engineering

Dry Thermophilic Anaerobic Digestion Process of Swine Manure and Rice Straw: Towards a Sustainable Swine Manure Treatment System Based On Forage Rice Paddy

Authors

Hosomi, M. - Presenter, Tokyo University of Agriculture and Technology
Suzuki, K., Tokyo University of Agriculture and Technology
Riya, S., Tokyo University of Agriculture and Technology
Zhou, S., Tokyo University of Agriculture and Technology
Terada, A., Tokyo University of Agriculture and Technology

This study proposes a sustainable swine manure treatment system based on a forage rice paddy. Forage rice crops cultivated in a rice paddy are fed to livestock whereas the unused straws are provided to a dry thermophilic anaerobic digestion process as a substrate with swine manure to produce methane. Digested residues can be applied to a rice paddy as a fertilizer. In this study, effects of rice straws/swine manure (C/N) ratio and sludge retention time (SRT) on methane yields were investigated. Three bioreactors with C/N ratios of 8 (without rice straw addition), 20 and 30 were operated with decrease in SRT. The bioreactor with C/N ratio of 8 eventually lost methane production potential because of ammonia inhibition derived from swine manure. The highest methane yield of 110 Nm3/t-substrate was obtained at SRT of 30 day and C/N ratio of 20 and 30. Analysis on the system sustainability will be presented.