WASTE WATER TREATMENT PLANT In Saint-Petersburg (RUSSIA) Olga Nikolaeva, 2008

The south-western treatment facility. The main purpose of the most important project in last year is improvement of the Baltic region ecology. The south-western treatment facility is modern station supply with technically for biological treatment with cleaning of phosphorus and nitrogen.

Construction of south-western treatment facility began in the year But in 1993 construction was stopped, because there was no financing. At that time the construction was 60 percent done. In 2003 after agreements with western banks, companies and investors decided construction would continue. The ceremonial unveiling south-western treatment facility took place in September,22 in sedimentations History.

The south-western treatment facility’s productiveness Is m 3 per day (3,8m 3 /s). With the SWTF operating it cleans 85 percent of S-Petersburg’s waste water. Consequently S-Petersburg is approaching European standards.

The SWTF process for waste water treatment is traditional for Russia and other countries. Such flow sheet include:  initial clarifier,  aero tank’s biological treatment,  second clarifier,  decontaminated the effluent flows into the Gulf of Finland. There is using reagent in abrading process for increase effect waste treatment.

initial sedimentation aero tank second clarifier

The qualitative composition of waste water, which comes in to the Baltic Sea every year is: suspended substances - 21 thousand tons, general phosphorus thousand tons, general nitrogen- 3б5 thousand tons, organic contaminant- 23 thousand tons.

Before outputting in to the Gulf of Finland water goes through ultraviolet disinfection. In the past ten years the method of disinfection of water using ultraviolet radiation has grade popular. The application of this method allows to get the necessary water quality in the city and in the manufacturing enterprise. It is a deciding factor in ecological problems as well.

Technology of water disinfection with ultraviolet radiation has a lot of advantages in comparison with oxidative technology namely: Has a high performance on bacteria, viruses and protozoa; There are no side effects. For example, chlorination and ozone treatment, which has negative influence on human’s health and water environment ; There is no need for working with toxic materials such as chlorine and chloride-bearing reagents. There is no need for organizing express safeguards; There is no negative effects after a ultraviolet over dose; The operational expenditures are low, because ultraviolet’s equipment has a small power draw; The ultraviolet equipment is very compact. There is no system of the outlying districts for servicing and, as a consequence, fundamental costs of ultraviolet station’s construction are low;

Water output after disinfection

Now in SWTF there are alive crayfishes. They are looking after tap water condition in Saint- Petersburg. They are officially working in the central water works since the end of 2005 year. the crayfish

Saint-Petersburg’s “Vodokanal” promise, that invertebrate’s health will not subject to such working, water in Saint-Petersburg are satisfy the international’s requirements. The crayfishes as a worker is not a joke. It is extremely serious modern system for monitoring quality of water. It was cultivated specially for Saint-Petersburg’s “Vodokanal”. Such method was never used before. In the world tried to apply fishes, as a index of water quality, but if the water had the inferior quality fishes would die. “Vodokanal” is using crayfishes more humanely. In the crayfishes’ back there are sensors. These sensors are monitoring the crayfishes’ palpitation. When the quality of water is worse it immediately reflects in the ‘cardiogram’. With all this going on crayfishes look like full-workers: they are working three days and after that have a rest.

Waste water cleaning - Remove biological nitrogen and phosphorus. - Cleaning in aeration tank-displacer with low level nutrient medium for microorganisms. - Flotation and/or filtration post treatment. ВООТ diagram (Build, Own, Operate, Tell).

Processing of waste water and sediments Mechanical assortment Getting fuels from siftings Getting manure gas (methane) sediments dehydration and drying Gas processing Internal gas collection Preliminary bio gas cleaning Getting from bio gas thermal and/or electrical power Getting transport fuel from bio gas

Brief results of SWTF working are: reduction of all types of chemical pollution: biogens, heavy metals, mineral oils is decrease twice as against 2003 year, and since 1985 is decrease 8 times.

In SWTF was built a incineration facility for the waste water sediments. In accordance with technology in this facility during incineration sewage volume of sediment are decreased in time. It has enabled a Decrease in areas for burial place. During incineration there are harmful substances. These harmful substances pass though a triple cleaning system. Thanks to the current technology of incineration 99 percents of harmful substances are held. Monitoring for condition of the air is routinely maked in the control area of the central air exchange in Belyi island from the very outset of the sediment incineration facility launching. There has been no deviation in facility’s work. The facility is using:  195 sewage collectors of deep location,  114 pumping facilities,  20 treating facilities,  9 refinement of drinking water facilities,  as well as 2 large facilities of wastewater cleaning.

Thank you for your attention!