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Nitrification of municipal effluents in fluidised bed reactors using immobilised microorganisms The problem Existing municipal effluent treatment plants designed earlier for the BOD removal are usually not suitable for nitrification at low temperatures, because of • Small plant dimensions and low sludge age, respectively • of biokinetical reasons. Consequences are in the cases of required nitrifications expensive plant extensions. Our problem solution means the Plant upgrading into fluidised bed reactors using microorganisms immobilised on adsorbing LEVAPOR-carrier. Immobilising nitrifying bacteria on adsorbing carriers they • more robust and efficient, • do produce lower quantities of excess sludge and • are able to maintain their activity even after a storage over 12 months. As a possible alternative to plant extension, it was considered to establish the nitrification by a susequent WWTP- upgrading via immobilisation of nitrifying sludge on 12 vol.% of adsorbing LEVAPOR-carrier. Results: After addition into the basin the carrier cubes became colonised and fluidised directly and despite to low temperatures (November) the nitrification has been established at 17°C within two to three weeks and kept efficient, achieving 70 to 80% nitrification over several months, despite to lower temperatures in December (12 °C). TKN-inlet- and NH4N-/NO3N-outlet concentrations during nitrification at 10 to 17°C by immobilised microorganisms. Summary • immobilising of the activated sludge, nitrification has been established within 2 to 3 weeks • the nitrification remained stable and efficient even at lower temperatures, of 8 to 13°C and increased volumetric N-loading rates • the existing aeration system was proven as sufficient for a practically full fluidisation of the colonised carrier cubes. • removal of excess biomass from the surface of carrier cubes occurred automatically by fluidisation without any additive . B. Nitrification and removal of hazardous pollutants from municipal effluents ( pilot plant tests) Comparison of immobilised -LEVAPOR-carrier - vs. suspended sludge Pilot plants In two parallel operated fluidised bed reactors, each of 3,1 m³, nitrification and hazardous pollutant removal of immobilised and suspended biomass have been compared. Additionally to higher degree of nitrification and denitrification ( due to inner pores of carrier cubes ), immobilised biomass achieved also a remarkably higher removal of polycondensed aromatic compounds.
Figure 1. Basic process flow diagram of the WWTP in Finnland upgraded by LEVAPOR
LEVAPOR GmbH • Kölner Str. 38 • D-51379-Leverkusen • Geschäftsführung Dr. Imre Pascik • Telefon: +49 (0) 2173 - 93 87 15 • Mobil +49 (0) 177 - 786 55 33 • e-mail: levapor@web.de
WHAT IS LEVAPOR? LEVAPOR - TYPES and PROPERTIES LEVAPOR-C adsorbing, porous carrier material for special microorganisms LEVAPOR-F for anaerobic reactors LEVAPOR - TYPES and PROPERTIES The LEVAPOR-Story OPERATIONAL AREAS LEVAPOR in OFF - GAS TREATMENT in BIO-TRICKLING FILTERS Biotreatment of off-gases from a waste water buffer Biotreatment of off-gases from a storage of plastic wastes Biotreatment of off-gases from a building for sludge presses Biotreatment of off gases containing styrene LEVAPOR IN WASTE WATER TREATMENT LEVAPOR in COD-elimination Treatment of toxic pulp mill effluents Treatment of chemical effluents Treatment of agrochemical effluents LEVAPOR in AOX-degradation LEVAPOR in nitrification Nitrification of municipal effluents Nitrifikation of complex industrial effluents Nitrification of inhibitory chemical effluents Nitrification of high salinity chemical effluents LEVAPOR in municipal effluent treatment Nitrification of municipal effluents LEVAPOR in small waste water treatment plants LEVAPOR in OFF - GAS TREATMENT in BIO-TRICKLING FILTERS Biotreatment of off-gases from a waste water buffer Biotreatment of off-gases from a storage of plastic wastes Biotreatment of off-gases from a building for sludge presses Biotreatment of off gases containing styrene BIOREACTORS for effluent treatment using LEVAPOR-carrier Biofilters Fluidised bed reactors NEWS IMPRINT LINKS CUSTOMER