Implementation of the technologic solutions focused on the prevention of water body eutrophication (best practices of SUE «Vodokanal of St. Petersburg»)

Summary

SUE «Vodokanal of St. Petersburg» has been the biggest water user in the Baltic Sea coastal zone; therefore the enterprise is obliged to meet the regulations of effluent discharge into the water bodies. The qualitative composition of the discharged effluents is regulated not only by the Russian standards but also by the international recommendations including the Helsinki Convention on the Protection of the Marine Environment of the Baltic Sea. Russia endorsed the Convention in 1998. Since that moment Saint-Petersburg and Vodokanal have been aiming at reducing raw wastewater discharges into the Baltic Sea and meeting the regulations of the effluent quality. The best practices of SUE «Vodokanal of St. Petersburg» implementing the technology of nutrients removal with the purpose of preventing water body eutrophication are presented. The international experience was studied; the laboratory and full-scale tests of different technologies of enhanced phosphorus and nitrogen removal were conducted. Kreal technology and its limitations revealed in the process of operation are described alongside with the process schemes designed by the University of Cape Town (UCT-Process) and Johannesburg University (JHB-Process) and implemented with the purpose of improving the efficiency of wastewater treatment. In order to provide for the stable phosphorus concentration in the effluent according to the regulations chemical removal of phosphorus was introduced. Starting from 2011 Saint-Petersburg has been fully meeting the HELCOM recommendations.

Key words

treatment facilities , wastewater , aluminium sulphate , total phosphorus , total nitrogen , eutrophication , ferrous sulphate