Heterotrophic denitrification kinetics in a pressurized sewer biofilm reactor Original Research Article

Nitrate dosage in sewers is a well documented method for odor and corrosion control. However, the knowledge of anoxic sewer processes kinetics is limited. 17 experiments were conducted in a lab scale sewer biofilm reactor, under steady state conditions, to study the kinetics of heterotrophic denitrification in a sewer pressure main, under 3 different temperatures (20, 25 and 30°C). Experimental results show that heterotrophic denitrification in the biofilm phase can be described by half order kinetics due to decreasing biofilm biomass concentration along the reactor. The temperature coefficient for heterotrophic denitrification is calculated and an empirical temperature dependent equation is developed to predict the biofilm phase denitrification rate in any pressure main.