HIGH NITROGEN CONTENT SLUDGE TREATMENT SYSTEM NOT DISCHARGING AIR POLLUTING GAS AND SLUDGE TREATMENT METHOD

摘要

PROBLEM TO BE SOLVED: To obtain a harmless non-putrefying good compost without discharging a malodor or polluting gas during fermentation to the atmosphere by fermenting high nitrogen content sludge along with wood pieces under an air passing condition and introducing ammonia gas generated therein into treatment soil comprising a specific three-layered structure. SOLUTION: Org. sludge, wood pieces and fermentation bacteria are mixed by a mixer 13 and this mixture is charged in a primary fermentation tank 1 to be subjected to primary fermentation. At this time, air is introduced into the tank from an aerating air taking-in port 3 and ammonia gas generated accompanied by fermentation is discharged from an ammonia gas exhaust port 5. The ammonia gas is introduced into treatment soil of a three-layered structure consisting of a gas introducing bed containing cobblestone and a piping, a diffusion bed comprising broken stone and an adsorbing and decomposing bed comprising soil to be treated. Thereafter, the sludge mixture is sent into a screening machine 6 and wood pieces are separated by screening and the residual sludge mixture is charged in a secondary fermentation tank 2 to be aged and fermented to obtain a soil like fermentation product.