The hydrothermal treatment is one of the thermochemical processes, treating waste in high-temperature and high-pressure water media to upgrade the material in a short time. Korean government has had an interest to employ a new municipal solid waste treatment system the mechanical biological treatment system. The hydrothermal treatment employed in this research is utilized using high-temperature water to treat the raw material. The dehydration performance of raw sample and hydrothermal products was determined using a centrifugal separator with variable speed from 2,000 to 14,000 rpm. The biomass composition of raw material should influence the property of the hydrothermal treatment product. The hydrothermal treatment can promote water removal from waste and biomass by improving the dewatering performance as well as the chemical dehydration. The scanning electron microscopy microphotographs of the paper and kimchi before and after the hydrothermal treatment.