Reconstruction experience of the wastewater treatment plant (Kargasok village, Tomsk region, Russia) using «constructed wetlands» technology

Abstract

Abstract Considered wastewater treatment plants (WWTP), located in Kargasok village (Tomsk region (average annual temperature -1,5°C)) are intended for complete biological treatment of household and close to them in the composition of the industrial effluent of the village. The design capacity of treatment is 700 m3/day. Sewage treatment facilities, performed according to the standard project TP 902-2-154 (without sludge sites and chlorination site of treated effluents) in conditions of low temperature of wastewater and the existing system of their supply for treatment did not provide a significant reduction in the degree of contamination of the effluent. Thus, the maximum excess of permissible discharges was observed for ammonium (at 162.21 mg/dm3 from the approved standards). The activities carried out in 2005 (construction of the phytocard1 (FK1), a siphon outlet device leveling the hydraulic load on the phytocard1 (FK1) and preventing the breakthrough of floating substances from the aeration tanks into the secondary sedimentation tanks (VO)) significantly increased the efficiency of the WWTP. Achieved standards for intestinal microflora, in a discharge in the river Ob there are no parasites and coliphages. The average annual cleaning efficiency for suspended substances was at least 95%, for organic substances - at least 70%, for ammonium - at least 58%. The nitrification process was not observed. To clean the effluent from the remaining nitrogen, the construction of an additional phytocard (FC2) was required. It was possible to reach the standards for permissible discharge after the final treatment of effluents at FK2 only for suspended substances and BOD filled gas, for the remaining pollutants it was not possible to reach the standards. This is due to a violation of the design of the FK1 and incorrect construction work at the FK2, which did not allow the ice to be hung out at both the FK2 and FK1. Approaches to the reconstruction of the WWTP in Kargasok village can be used for similar objects.