Process for biological wastewater treatment in an aeration tank

摘要

The biological sewage cleaning process, using an aeration basin, has a contact basin in front of the aeration basin, continuously fed with mechanically precleaned sewage. The contact basin, with a vol. less than 20% of the aeration basin, gives a partial denitrification to the sewage under anoxic conditions and back feed of water and sludge rich in nitrates. The pretreated sewage is fed into the aeration basin with high pump speeds, for carbon decomposition and the nitrification/denitrification reactions. Pref. the basin is aerated intermittently, with aeration times of more than 10 mins./hr., or 20 mins./hr. The aeration time intervals are set according to the amount of sewage fed to the basin. The high pumping speeds give a mechanical breaking-down action on the size of the flocking material passed into the basin, to increase the surface areas of the material within the aeration basin to increase processing speed. USE/ADVANTAGE - For the removal of nitrogen from the waste material. It has an effective action, in small sewage disposal plants, occupying little space and with low energy consumption, to give an improved sludge quality.