PROCESS FOR REMOVING SIMULTANEOUSLY CARBONACEOUS AND NITROGENOUS POLLUTIONS IN WASTE WATERS

摘要

Process for the purification of water using activated sludge in the presence of a mixed culture of nitrifying bacteria and of denitrifying bacteria. According to the process, aeration is limited so as to have a maximum dissolved oxygen content of 1.5 ppm and normally aerated zones and zones at the limit of anaerobiosis are alternated a number of times. According to a preferred method, the operation is carried out in an elongate tank with a series of aerated sections and nonaerated sections, water being fed in at a number of points. Application to the purification of raw effluents with a load per unit mass of 0.10 to 0.15 kg of BOD per kg of suspended matter per day.