In the autumn of 2008 Carlsberg Poland completed a long-term project of building on a Greenfield and adjusting its full wastewater treatment plant (WWTP) at Bosman Brewery, Szczecin, located in the north-western corner of Poland. The WWTP's purpose is to treat the breweries waste water and thereby reduce the environmental impact. The brewery's wastewater plant was developed with state-of-the-art technology and has a unique setup. The treatment of the waste water involves a set of
key process steps that combine an anaerobic-aerobic process with final dissolved air flotation (instead of the traditional settling tanks that have more environmental impact) and a dedicated sewer outlet to the river. Currently this set up is found in less than ten plants elsewhere worldwide.
The facility has the capacity to treat 3.000 m3 of water per day and an effluent load of 9 tons COD (Chemical Oxygen Demand) per day.
Whereas normally waste water plants are designed on larger areas with much more buffer and using a lot of idle space, the Bosman WWTP is - due to the compact size and the many levels in the facility- one of the smallest of such plants in Europe but has the same capacity as larger plants. Carlsberg Poland received support from the regional environmental facility in the form of a soft loan.
Saving space, reducing electricity use and improving soil
As the city of Szczecin was planning to upgrade its wastewater disposal system in early 2000's, the brewery effluent was required to be treated. The brewery analysed various options and the independent full treatment plant was selected as most feasible in a long-term.
Prior to wastewater plant development the brewery carried out the necessary pre-work such as the separation of by-products, water minimisation and restoration of existing sewer systems.
Due to geographical restrictions (only 1.100 m² available) the wastewater plant had to be designed in a very compact format. The solution included a facility consisting of vertical reactors and three-storey machinery rooms were developed.
The construction and adjustment phase lasted five years, including temporary outlet and final river outlet and adjustment of final effluent clarification by dissolved air flotation. As the plant is very compact and tailor-made an integrated approach to plant maintenance and process operation is essential for sustaining the relevant performance of the facility.
The anaerobic treatments process saves substantial amount of electricity otherwise used for effluent aeration and reduced by a factor of 3 the sludge production of the plant. The wastewater sludge residual can be used safely as a soil improver.
The brewery has solved its wastewater disposal prior to the final solution in the city and is a substantial contribution to pollution reduction in the Oder River and the Baltic Sea.