Nitrifikationshämning i tvätteriavloppsvatten

Sammanfattning: The nitrification process is known to be the most sensitive link in biological nitrogen removal used in many wastewater treatment plants. Many different inhibitory substances can disturb these sensitive bacteria and in that way cause reduced nitrogen removal. The aim of this study was to investigate the nitrification inhibition in a laundry wastewater before and after internal chemical treatment. In addition the used detergents, containing alcohol ethoxylates, and also the bleaching agent at the facility were tested for nitrification inhibition in order to investigate their possible contribution. Furthermore activated carbon was investigated as a method to decrease inhibitory substances in the wastewater. The results confirm that the facility do have problems with to high levels of nitrification inhibition. The results also reveal that there is just a small decrease in nitrification inhibition in the effluent compared to the influent, indicating that the chemical treatment is not sufficient in removing these inhibitory substances in the wastewater. This tests also show that both the bleaching agent and detergents containing alcohol ethoxylates can be inhibitory to the nitrification process. It was also found that activated carbon can be utilized to remove the inhibiting substances from the wastewater