METHOD OF CLEANING CONTAMINATED WATER Russian patent published in 2000 - IPC

FIELD: treatment of domestic and industrial sewage. SUBSTANCE: method consists in biological cleaning of contaminated water with activated sludge by means of double-stage aeration systems; at first stage, contaminated water is introduced into first aeration tank containing non- acid medium; cleaned sludge is removed from system. As a result, 70 to 80% of phosphates and nitrates contained in contaminated water are also removed from system. At second stage, water cleaned at first stage is delivered to second aeration tank filled with oxidizing medium where nitrates are formed; sludge obtained at first stage is also loaded in second aeration tank. Cleaned sludge thus obtained is returned to repeated cycle. One or both aeration tank contain ion-exchange resins which get swollen in water increasing in volume by 200 to 350 times and binding soluble ions of metals. EFFECT: enhanced efficiency of cleaning sewage from ammoniates and phosphates; complete removal of toxicants; low operational expenses. 10 cl, 1 dwg