GB No. 4, spring 1991
All municipal waste water and part of industrial waste water of the Gdańsk and Sopot area (total volume of wastes 200,000 m3/d where municipal wastes amount to 160,000 m3/d) are treated prior to discharge into receiving waters. The treatment occurs in two large plants:
Industrial waste waters are also treated in a number of small plants; yet the wastes in these plants are only partially treated.
Here are the characteristics of the two main waste water treatment plants:
The biological section comprises:
Effectiveness of the plant is:
In the case of this plant
phosphorus and nitrogen pose a problem
since these elements are not
The effectiveness of this plant is poor. BOD5 reduction is lower than 30% and sludge removal doesn't exceed 60%. Sludge treatment is a considerable problem as digestion does not proceed properly because of the faulty design of the digestion chambers.
Low effectiveness of waste water treatment adds up to the devastation of the beaches in the Gdańsk area.
Unfortunately the situation cannot be changed before the biological section of the plant has been build, which will not take at least then 5-6 years.
The additional and urgent problem in the case of this plant is the difficulty in nitrogen and phosphorus removal.
Dr inż. B. Kasterka
Dept. of Water and Waste Water Techn.
Institute of Hydrotechnics
Technical University of Gdańsk