Application of half-order kinetics to sulfur-utilizing autotrophic denitrification for groundwater remediation

The kinetics of sulfur-utilized autotrophic denitrification of groundwater was evaluated in batch tests to obtain kinetic parameters. Experiments were performed in media bottles containing varying NO3 (-)-N concentrations (20, 44, and 77 mg/L) with 4.0-4.75 mm-sized sulfur particles. Alkalinity was set as a constant in all experimental containers at 850 mg/L as CaCO3. The half-order kinetic model was found to adequately describe the process efficiently, yielding denitrification rate constants of 4.36, 5.51, and 6.91 mg-N-1/2/L-1/2 center dot A h in the presence of NO3 (-)-N at 20, 44, and 77 mg/L, respectively. The rate of denitrification increased with the increasing initial NO3 (-)-N concentrations.