KOLKÄLLA UR SLAM FÖR BIOLOGISK DENITRIFIKATION, Carbon Source by Anaerobic Sludge Treatment for Biological Denitrification
The introduction of biological nitrogen removal at many sewage treatment plants in Sweden, particularly those located at coastal regions up to Stockholm archipelagio in the east, is now proceeding primarily by plant trial operation. The deficit of an easily biodegradable carbon source for anoxic denitrification and the cold winter climate are the most characteristic problems in Sweden. This report includes the results of experimental works and cost calculations on anaerobic enzymatic hydrolysis of primary or mixed raw sludge under formation of volatile organic acids (acetic acid etc.). This is in principle the first stage in an anaerobic two-phase sludge digestion process, which has several advantages compared to the conventional one-phase process with respect to sludge digestion according to literature. The generated soluble BOD in the waterphase may be separated in a wash-thickener by dilution water or by mechanical means (e.g. centrifuge) in order to increase the yield. “Complete abstract not presented.”