Carbon Source for Denitrification from Pre-Precipitated Sludge
The organic matter not removed by gravity in a pre-sedimentation tank is in a stable suspension consisting of particles smaller than 0.1 mm. This stable suspension may be destabilized by using low molecular, positively charged metal salts such as polyaluminium sulphate or polyaluminum chloride. These salts are also able to form fluffy hydroxide flocs that can arrest the destabilized particles through general sweep coagulation. Large aggregates capable of being sedimentated are formed. Dissolved compounds like phosphorus are precipitated at the same time. Figure 1 shows that with an effective flocculant and with good initial mixing and floc formation, particles down to 0.1 µ may be destabilized, coagulated and removed from the wastewater (Levine et. al., 1985).
KeywordsDenitrification Rate Anaerobic Treatment Full Scale Test Hydrolysis Procedure Capillary Suction Time
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- Levine, A.D., Tchobanoglous, G., Asano, T.: Benefits of Particle Size Management for Biological Wastewater Treatment. (Prepared for presentation at the 1985 ASCE National Conference of Environmental Engineering, Boston, Mass.) University of California, Davis, 1985Google Scholar
- Ødegaard, H.: Particle Separation in Wastewater Treatment. (Presented at the 7th European Sewage and Refuse Symposium, Munich). The Norwegian Institute of Technology, Norway, 1987Google Scholar
- Karlsson, I.: Pre-Precipitation for Improvement of Nitrogen Removal in Biological Wastewater Treatment. In: Pretreatment in Chemical Water and Wastewater Treatment, H.H. Hahn and R. Klute (eds.). Springer, 1988Google Scholar
- HYPRO: The Eureka Projekt. (Its participants are: Sweden: Kemira Kemi AB; Denmark: I. Krüger AS, Danisco Biotechnology AS, Department of Environmental Engineering, The Technical University of Denmark, Water Quality Institute; Norway: Norwegian Hydrotechnical Laboratory, SINTEF Group NHL, AS Ferriklor)Google Scholar
- Mönnich, C.: Kvävereduktion vid Flyinge Reningsverk. Internal report Boliden Kemi AB, 1989Google Scholar
- EPA: Dewatering Municipal Wastewater Sludges. Design Manual, 1987Google Scholar