This study was conducted to evaluate the effects of physical characteristics. Twelve specific odorous compounds and various sources of bacteria were tested via treatment of food waste using an ultra-thermophilic aerobic composting process. Food waste was mixed with seed material and operated for 47 days. During composting, the temperature was maintained at 80-90°C. The variations in O2, CO2 and NH3 production suggested typical microorganism-driven organic decomposition patterns. After composting, the concentrations of 12 specific odorous compounds other than ammonia did not exceed the allowable exhaust limits for odor. After composting, thermophiles represented 50% of all bacteria. After composting, the percentage of thermophile bacterial increased by 15%. Therefore, both stable composting operation and economic benefit can be expected when an ultra-thermophilic composting process is applied to food waste.

Hydrothermal carbonization (HTC) is a highly effective technique for treating lignocellulosic biomass and organic waste of various shapes and moisture content. The solid product of HTC is friable, hydrophobic, and increased in mass and energy densification compared to the raw biomass. also solid product is similar regardless of the type of biomass used. A liquid solution of five carbon and six carbon sugars, along with various organic acids and 5-HMF, is also produced from HTC of lignocellulosic biomass. The gaseous phase product consists mostly of CO2. Solid product has the similar characteristics to low rank coal. The solid fuel characteristics of feedstock was increased with reaction temperature and time via HTC process. However, mass yield was decreased with increasing temperature and time. Therefore, it is necessary to optimize the reaction temperature and time for HTC. The HTC process produces the solid product and a large amount of water. Thus the reuse or treatment techniques of liquid product is necessary. Therefore, potential of biological treatment of HTC liquid product was evaluated.