| 摘要 |
PROBLEM TO BE SOLVED: To simplify a treatment process while facilitating operation control by treating sewage of an excretion system and sewage of a purifying tank sludge system among sewages fed in excretion treatment facilities in pretreament processed of respective separate system so as to remove impurities such as paper or cloth or solid matter such as sand. SOLUTION: Raw excretion (or purifying tank sludge) fed in excretion treatment facilities is received in a sand sedimentation receiving tank and solid matter such as sand is sedimented and the sewage from which the solid matter such as sand is removed is allowed to overflow a sand sedimentation tank to be sent to a receiving tank and sent to an impurity removing apparatus from the receiving tank by a pump equipped with crushing function. Impurities such as fibers, for example, cloth, paper or plastics are removed in the impurity removing apparatus and dehydrated to be subjected to incineration treatment and landfilling treatment. The sewage from which impurities are removed is supplied from a storage tank to an aeration tank to receive the addition of an inorg. flocculant and subsequently subjected to aeration treatment and solid-liquid separation treatment in succession. Further, first and second reaction tank are brought to an anaerobic state to perform denitrification and the aeration tank is brought to an anaerobic state to perform nitration reaction. |
