A Kinetic Model for Autotrophic Denitrification using Sulphur:Limestone Reactors

Abstract

Abstract The kinetics of autotrophic denitrification of groundwater by Thiobacillus denitrificans in a sulfur:limestone upflow reactor was examined in order to predict effluent concentrations. Experiments were performed using water containing 60 and 90 mg NO3—N/L and sulfur and limestone with average particle size of 3.5 mm. Results clearly showed that nitrate was completely removed from 60 and 90 mg NO3—N/L influent concentrations. The results showed that the autotrophic denitrification rates in sulfur:limestone reactors can be described by half-order kinetics. The half-order reaction rate constants for the entire media were estimated at 1.34 and 1.54 mg1/2/L1/2 h for influent concentrations of 60 and 90 mg NO3—N/L, respectively.