| 摘要 |
PURPOSE:To carry out the capacity enhancement of a treating installation economically and efficiently by a method wherein a biological nitration and denitrification tanks are provided in parallel to a conventional treating procedure of a high nitrogen containing sewage and the treatment is carried out which a treated water is mutually transferred therebetween. CONSTITUTION:An excretion type sewage 1 subjected to the pretreatment to remove crude floated substance is firstly stored in a storage tank 4 and a part thereof is sent to a newly-established denitrifycation tank 13 and the remainder thereof is sent to a first anaerobic digestion tank 5, thereafter supplied to a second anaerobic digestion tank 6 and a dilution regulating tank 8. In the denitrification tank 13, a mixed liquid 17 formed by partially taking a part of a treated water from an aeration tank 9 is flowed into a newly-established nitration tank 16 to be mixed with a nitrated mixed liquid 15 to carry out the denitrification. Thereafter, this mixed liquid 14 is flowed into a dilution regulating tank 8. As described above, a high nitrogen containing sewage is treated in good efficiency be combining two system treatments. |
