Reconstruction of the right-bank wastewater treatment facilities
of Irkutsk

Summary

Practically in all Russian cities the deterioration of the water and wastewater networks and facilities averages about 70%. Many of the facilities have been not only worn but also outmoded and do not meet the current technical and environmental requirements. The right-bank and left-bank wastewater treatment facilities of Irkutsk for many years have been overloaded: at the design capacity of 300 thousand m³/day the actual incoming wastewater flow has been 360 thousand m3/day. Lately, due to the significant reduction of the specific water consumption the incoming wastewater flow has reached 295 thousand m³/day. However the composition of the wastewater in relation to many parameters changed significantly; whereas the treatment efficiency lowered. As a result of the long time operation without heavy overhaul under the conditions of the corrosive wastewater a great number of reinforced concrete storage tanks, pipelines and equipment have been in poor state and need dismantling, repair, replacement and upgrade. In order to improve the efficiency of wastewater treatment the following basic process stages have been proposed: primary mechanical treatment; grit removal; biological treatment with nitrogen removal in the processes of nitrification-denitrification; chemical phosphorus removal by sedimentation method; enhanced treatment (organics and ammonia nitrogen removal) in a moving-bed bioreactor; suspended substances removal by enhanced tertiary treatment in sand filters; UV-disinfection. Upon complete reconstruction the required wastewater treatment level will meet the sanitary standards of the effluent quality to be discharged into water bodies.

Key words

reconstruction , sewerage treatment facilities , efficiency of treatment , wastewater composition