TREATMENT OF ORGANIC WASTE

• Main Authors: MORO MASASHI, SOEDA YUJI, SHIBATA TOSHIYUKI, WAKAHARA SHINICHIRO, YAMAMOTO TETSUYA
• Format: Patent
• Language: English
• Published: 17.08.1999
• Edition: 6
• Subjects: CHEMISTRY; DISPOSAL OF SOLID WASTE; FERTILISERS; MANUFACTURE THEREOF; METALLURGY; ORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C, e.g. FERTILISERS FROM WASTE OR REFUSE; PERFORMING OPERATIONS; RECLAMATION OF CONTAMINED SOIL SOIL; TRANSPORTING; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

PROBLEM TO BE SOLVED: To suppress a soluble fermentation inhibitor such as ammonia nitrogen and to efficiently promote methane fermentation by draining a part of a fermented liquid in a fermentation tank in the process of methane fermentation, subjecting the drained liquid to solid-liquid separation, diluting the separated solid content and circulating the diluted content into the fermentation tank. SOLUTION: A crushed waste 37 after crushed and classified is mixed with a dehydrated sludge 32, the concn. of whole vaporization residue of the mixture is controlled, and the mixture is subjected to methane fermentation in an anaerobic fermentation process 37. In this process, a part of the fermented liquid 38 in the fermentation tank is drained and subjected to solid-liquid separation in a solid-liquid separation process 40. By sending the liquid content 39 to a denitrification process 41 for biological denitrification, denitrification reaction is caused with volatile fatty acids as the BOD source and thereby, volatile fatty acids and ammonia nitrogen are decomposed and removed at one time. The solid content 40 containing methanogen is returned to the fermentation tank. By this method, while the concn. of the soluble fermentation inhibitor is decreased, the concn. of the solid content containing methanogen is controlled by controlling the amt. of a diluting water to efficiently carry out fermentation.