Hiroshi Eya

General Manager of Garbage Bio-Disposing Technology Project, Household, Industrial and Other Waste Advanced Treatment Technology Promotion Headquarters, Clean Japan Center
(3-Chome 6-2 Toranomon, Minato-ku, Tokyo 105 Japan)

Abstract

A new and practical dehydration technology and system have been developed for aerobic fermentation and composting garbage with high moisture. Dehydrability tests were carried out using garbage with a moisture content of about 80-88%. It was found that the sample was dehydrated efficiently when it was pressed with a load of 2kg/cm2 after being shredded to 5mm and pretreated under facultative anaerobic conditions for several days. A certain degree of the facultative anaerobic degradation of cellular tissue of the garbage seems to cause easy dehydrating. After that, this pretreating technology was applied to a NEDO verification test plant which composts 500kg of garbage a day, it was observed that the system consisted of a shear-type shredder, paddle-type facultative anaerobic pretreating container, screw press-type dehydrator and scoop-type fermentor which were effective in composting. It was confirmed that dehydration efficiency improved very much when the shredded garbage was simply left under facultative anaerobic conditions for several days and it was able to compost without adding any materials for moisture control, energy for drying and so on, which are necessary in conventional technology.

Key words: garbage, dehydration, facultative anaerobic, aerobic fermentation, compost