METHOD FOR BIOLOGICAL PURIFICATION OF AMMONIUM-CONTAINING WASTE WATER Russian patent published in 2014 - IPC C02F3/30 C02F101/16 

FIELD: chemistry.

SUBSTANCE: invention can be used for biological purification of ammonium-containing waste water, including at temperature of 7-25°C. The waste water is fed into an aeration tank (3) in which ammonium contained in the waste water is converted at a given oxygen concentration to elementary nitrogen. The formed excess sludge is fed for fermentation (13) which is accompanied by gas release. The sludge is then fed for drying, and the muddy water separated from the sludge, which contains 500-2000 mg/l nitrogen at 25-39°C, is fed into a deammonification reservoir (18), where nitrogen compounds contained in the muddy water are converted to elementary nitrogen. The excess sludge formed in the reservoir (18) is fed into an aeration tank (3), in which oxygen concentration is maintained below 1.0 mg/l. The ammonium contained in the waste water is first converted by anaerobically oxidising bacteria to nitrite. The ammonium and nitrite are then converted to elementary nitrogen by aerobically oxidising bacteria (ANAMMOX), particularly planctomycetes. Before feeding for fermentation, the excess sludge formed during deammonification in the aeration tank (3) is divided into a heavy phase containing anaerobically ammonium oxidising bacteria (ANAMMOX) and a light phase. The sludge heavy phase is fed into the aeration tank (3) and the light phase in form of excess sludge is fed for fermentation (13).

EFFECT: method provides energy-efficient biological purification of cold waste water containing ammonium with low content of organic carbon.

22 cl, 1 dwg