Abstract: “A two well model was fabricated to study the application of Thiosphaera pantotropha for in situ denitrification. The effect of varying C/N (Carbon/Nitrogen) ratio (0.92-2.5) on denitrification was observed with sodium acetate as a carbon source. At C/N ratio of 2.1 the reduction in nitrate nitrogen was sufficient to bring it below WHO limits of 10 mg/l from an initial concentration of 50mg/l. At a C/N ratio of 2.3, the treated water nitrate was reduced to zero. DO during various phases of experiment ranged from 5.58 to 2.86 mg/l indicating that highly aerobic condition prevailed throughout. As the C/N increased from 0.92 to 2.5. The head loss increased from 30 to 72 cm.”

Keywords: Groundwater, in situ denitrification, acetate, T.Pantotropha