Successful start-up of the largest municipal MBR plant in Russia

In Sovetsk (Kaliningrad, Russia) one of Russia's most modern municipal sewage treatment plants has been built with the financial support from the European Union. The plant is designed for 120,000 PE. The plant uses one of the presently most innovative wastewater treatment techniques, the so-called MBR system. It was successfully commissioned in October 2013 and has superbly mastered the first severe winter months.

Sovetsk, before 1946 known as Tilsit, is a town in the Russian exclave Kaliningrad and lies directly on the border to Lithuania at the confluence of the Tilse river and the Neman river. The Queen Louise Bridge connecting the town to Lithuania is one of the town's landmarks. Beside its most famous product, the Tilsit cheese, the town is known for the Treaties of Tilsit, a peace treaty between France, Russia and Prussia, that was signed there in July 1807 by Napoleon I. Until last year Sovetsk used a rather obsolete solution to "treat" their wastewater. The wastewater was collected in a central pumping station, still from the old Soviet Union times, and most of it directly discharged into the Neman river without prior treatment. The Neman river is approximately 937 km long rising in Belarus and flowing through Lithuania before draining into the Curonian Lagoon and then into the Baltic Sea.

Table 1: Limit values to be met when discharging the Sovetsk wastewater into the Neman river

To improve the environmental balance the European Union financially supports the expansion and refurbishment of local sewage treatment plants. This made it possible to build a new wastewater treatment plant in Sovetsk. The plant has been designed for approximately 120,000 PE (26,000 m³/d) to meet the requirements of the catchment area size and the connected industrial companies. As the quality of the clarified wastewater will have to meet Russia's very strict future discharge standards, one of the country's most modern municipal sewage treatment plants has been built at Sovetsk. The plant uses one of the most innovative wastewater treatment techniques, the so-called MBR system. After mechanical-biological treatment the wastewater is filtered by membranes with this system. The effluent is completely free from suspended matter and virtually free from bacteria and germs.

The new plant has been planned by a Lithuanian planning office and built by the Russian company UAB Baltlistroj which has chosen HUBER SE to supply the complete mechanical equipment for wastewater pretreatment and the complete membrane filtration system. Today, the sewage treatment plants is equipped with two Ro5 Complete Plant units (270 l/s), one Ro 3.1 Sludge Acceptance Plant, one RoSF4 Grit Washer size 2, and 24 membrane filtration units type HUBER VRM 30/640 (with in total 92,160 m² membrane surface). During both the planning and implementation phase we have been there for the customer as a competent and reliable contact partner for all questions around MBR plants.

The overall concept of the Sovetsk sewage treatment plant comprises mechanical wastewater pre-treatment (3 mm RPPS) and equalisation of hydraulic flow peaks (2 buffer tanks). To be able to flexibly react to varying inflow conditions that may occur in the future and to have an as redundant system as possible, both the biological treatment stage and the membrane filtration system have been designed as multi-line systems. Three identical aeration tanks (loop-type tanks, preceding denitrification) with a total aeration volume of 10,350 m3 are available on site for the biological treatment process. The layout of the biological treatment system has been based on the typical MBR parameters for sludge load, sludge age and 10 kg/m³ DS content. The following membrane filtration plant is a six-line system with four filtration units in each tank. This solution makes it possible to react to varying flow rates by switching on or off individual lines and to ensure optimal and economical plant operation. The membrane filtration system is operated with a flux of up to 25 l/m2*h, depending on the inflow conditions.

The construction time of the complete sewage treatment plant was two and a half years, starting in spring 2011 until completion in November 2013. Some peripheral buildings and the electrical control station are still under construction. The HUBER machines have been delivered to the site as several lots one after the other as the construction work progressed. The equipment of the mechanical pre-treatment stage was put into operation in spring 2013 already. The heart of the plant, the first lines of the membrane filtration system, could be put into operation in October 2013.

Presently, two lines of the biological wastewater treatment system and four lines of the membrane filtration system are in operation to handle the presently occurring wastewater volumes. The plant has operated perfectly even during the first severe winter months and reliably achieved the requested throughput and also met the effluent standards to the full satisfaction of the customer. Presently, the plant is still attended by the personnel of UAB Baltlistroj but in spring 2014 it will officially be handed over to the end customer, the municipality of Sovetsk.