Oxygen-limited decomposition of food wastes in a slurry bioreactor

Environmental Biotechnology Laboratory, Department of Chemical Engineering, School of Environmental Science and Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang, Kyunghuk 790-784, South Korea The slurry bioreactor system is an effective means for treating highly saline food wastes, which may not be recycled as composts. The effect of aeration rate was investigated in a slurry bioreactor as a major factor affecting the slurry-phase decomposition of food wastes. The aeration rate affected significantly the decomposition performance and the composition profiles of the liquid and solid phases. The decomposed carbon was almost linear with oxygen consumption, indicating that the slurry-phase decomposition of food wastes was limited by oxygen transfer. The oxygen requirement for decomposing 1 g organic carbon in food wastes was estimated to be 61.5 g O₂.