SBR technology used for advanced combined municipal and tannery wastewatertreatment with high receiving water standards

The wastewater treatment plant (WWTP) in Nowy Targ, Poland, is the largest in Europe based on classical sequencing batch reactor (SBR) technology. The plant was completed in April 1995 as one of the essential elements in a pr ogram for the protection of the water quality in the Czorsztyn Reservoir. T he process technology was designed for application to a typical municipal w astewater with a separate unit to treat tannery wastewater containing chrom ium Experience from plant operation showed that the municipal wastewater in flow to the WWTP included tannery wastewater with increasing chromium conce ntrations, caused by poor wastewater management in the city. The average va lue in the influent was around 3 mg Cr/l (1996-1997) and showed an increasi ng trend. Investigations were focused on identification of the factors affe cting the process performance. In this paper, evaluation of the treatment e fficiency and process performance during 2 years of plant operation is pres ented, including studies of nitrification, denitrification and biological p hosphorus removal. A cycle analysis was performed to investigate the reduct ion of different parameters during different phases of a cycle. Results of a sludge activity study based on OUR, AUR and NUR tests are presented and d iscussed. (C) 1999 Published by Elsevier Science Ltd on behalf of the IAWQ. All rights reserved.