Special online analysis of nh4 required by new method for nitrogen elimination - Dr. Volker Koschay and Hans-Peter Mascha

Conventional methods of waste water treatment at municipal plants include the treatment of process waste water from the sludge processing in the main flow of the clarification plant. Supernatants and mud liquids lead to a significant increase in nitrogen contamination. The waste water from sludge processing often shows an NH4-N concentration of 1000 mg/l and more. This increases the total N discharge values in a waste water treatment plant (WWTP).

As regards the German WWTP Landshut, the combined treatment of both the municipal waste water and the discontinuously accumulating process water from sludge processing in the plant would have required the enlargement of the nitrification volume due to high NH4 peak loads. In order to fullfill the legal requirements of 13 ppm total Nitrogen at the outlet of the plant, this would have involved building costs in the order of 30 million Euros for WWTP Landshut, which was built for 270.000 inhabitants.

Therefore, the operators tested a new method with regard to the treatment of partial flows of process water from sludge processing which, in the meantime, has been patented as "Terra-N – method".