Possible inhibitory effect of selected detergents used in food industry on wastewater treatment and especially on Grødaland wwtp.

Abstract

Grødaland waste water treatment plant (wwtp) is treating industrial waste water coming from food industry. As food industry consumes large amounts of detergents for food processing equipment cleaning, the wwtp receives wastewater contains large amount of chemicals. The presence of high detergents concentration in biological wwtp may interact with active biomass resulting in lower treatment efficiency. The goal of this project was to look at the possible effects of detergents used in upstream facilities on Grødaland wwtp. Based on industrial chemical consumption, a model was created in order to calculate the maximum concentration of each detergent in the reactor. Respirometric inhibition test were performed according to the model results. The maximum concentration of the various detergents varies between 0.5 and 143 ml/m3. As the range was wide, different testing ranges were defined. The inhibition experiments on the 17 chemicals results in constant inhibition with increasing concentration on 2 decades. Only one chemical shows high inhibition at the highest concentration but as this concentration was almost 10 times higher than the maximum concentration, it has been status that under normal conditions or under more of concentrated ones, the presence of chemical should not impact the waste water treatment process.