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
Consequences are that in the cases of nitrification expensive plant extensions are required.
2. Our problem solution results in
Plants being upgraded into fluidised bed reactors using microorganisms immobilised on adsorbing LEVAPOR-carrier.
Nitrifying bacteria immobilised on adsorbant carriers become more robust and efficient, produce lower quantities of excess sludge and are able to maintain their activity even after a storage over 12 months.
A. Upgrading of a small municipal WWTP with aerated basin of 45 m³, for nitrification in winter, by filling it with 12 vol.% of LEVAPOR carrier
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.
After addition into the basin the carrier cubes became colonised and fluidised directly and despite the low temperatures (November) the nitrification was established at 17°C within two to three weeks and kept efficient achieving 70 to 80% nitrification over several months, despite even the lower temperatures in December (12 °C).
Nitrification performance of the plant at different temperatures
Immobilising the activated sludge, nitrification was established within 2 to 3 weeks.
The nitrification remained stable and efficient, even at lower temperatures, of 8 to 13°C with increased volumetric N-loading rates.
The existing aeration system was proven as sufficient for almost a complete fluidisation of the colonised carrier cubes.
Removal of excess biomass from the surface of the carrier cubes occurred automatically by fluidisation without any additional measure.
B. Nitrification and removal of hazardous pollutants from municipal effluents ( pilot plant trials)
Comparison of immobilised -LEVAPOR-carrier - vs. suspended sludge
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. In addition 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.
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Cold weather can turn wastewater plants topsy-turvy, upending all one’s hard work to maintain compliance. When you are attempting to maintain adequate nitrification in your wastewater treatment plant (WWTP) to ensure that nitrogen associated permit limits such as Ammonia-Nitrogen (NH3-N), Total Kjeldahl Nitrogen (TKN), and Total Nitrogen (TN) are met, it is essential to stay on top of nitrification.
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The demand for efficiency improvement in municipal and industrial wastewater treatment plants (WWTP’s) is increasingly based on problems related to the water quality, process stability and/or insufficient performance in the COD removal and/or nitrification process.
New, stricter requirements or the need for higher removal efficiency intensify the demand for optimizing the existing technology by means of “tuning“.
This article is about the efficiency improvement of existing biological treatment...
Our nitrification process was originally developed for ammonia removal from activated sludge final effluent. However, it has since been applied to sludge liquor ("reject water", "centrate" or "filtrate") treatment. It is also suitable for nitrification of potable water sources (e.g. surface or ground water) prior to chlorination, to reduce the formation of chloramines.
Ammonia removal down to 1 mg/L
Energy consumption reduced by at least 30%
Nitrification rate up to 2.3 kg NH3-N m3 d-1
SS reduced by up to...