METHOD OF EXTENSIVE TREATMENT OF SEWAGE AND BIOLOGICAL EXTENSIVE TREATMENT STATION Russian patent published in 2004 - IPC

FIELD: treatment of sewage at concentrated organic contaminants. SUBSTANCE: proposed method is realized with the aid of plant divided into four successive zones under anaerobic and aerobic conditions; proposed method includes separation of activated sludge and purified water by settling followed by removal of activated sludge and purified water. Treatment of sewage in first two zones is performed under anaerobic conditions accompanied by mixing with the use of micro-flora secured on inert charge material reinforced with metal at absence of dissolved oxygen in first zone and concentration of dissolved oxygen in second zone not exceeding 1.0 mg/l. Treatment in third and fourth zones is performed under aerobic conditions. Treatment in third zone is performed with the use of micro-flora secured on inert charge material at concentration of dissolved oxygen of 2-3 mg/l and treatment in fourth zone is performed with the used of free-floating micro-flora at maintenance of excessive amount of dissolved oxygen above 4.0 mg/l. After settling, purified water is divided into two flows: one flow in the amount no less than 50% of total amount of purified water is directed to first zone and second flow is directed to final treatment under aerobic conditions with the use of micro-flora secured to inert charge material. Mixing in first two zones may be performed by means of ejection mechanical method. Activated sludge may be returned to first anaerobic zone and powder-like sorbents may be introduced into purified water before final treatment. Extensive biological treatment station includes biological treatment unit consisting of four reactors connected in succession; mounted after each reactor is settler with thin-layer modules. First two reactors are provided with ejection-type mechanical mixing units and inert charge for micro-flora is located in first three reactors; inert charge for secured micro-flora in first two reactors is reinforced with metal. Aeration units are located in third and fourth reactors. Final treatment unit made in form of reactor with inert charge for secured micro-flora and aeration device is provided with purified water re- circulating pipe line which is connected with first reactor and with pipe line discharging water after final treatment which is connected with decontamination unit which is connected in its turn with treated water discharge pipe line; aeration devices in third and fourth reactors may be made in form of ejection-type mechanical mixing units; settlers may be provided with activated sludge re-circulating pipe line connected with first reactor and final treatment unit may be provided with unit for delivery of powder-like sorbents. Proposed method may be used for cleaning sewage from nitrogen and phosphorus to maximum permissible concentration specified for fishing basins. EFFECT: enhanced efficiency; reduced treatment time. 8 cl, 2 dwg