The Kinetic Difference of Denitrification and Sulfate Reduction Conducted by Anaerobic Microbes

For investigating the competitive ability of denitrifying bacteria and sulfate reducing bacteria on the substrate in the anaerobic environment, denitrification and sulfate reduction experiments were conducted under the conditions of different carbon content and different nitrate/sulfate ratio, and the kinetic difference of denitrification and sulfate reduction was also analyzed. The experimental results showed that denitrification could essentially be completed in 7~9 h at the same condition of carbon source content, but sulfate reduction was completed after 12 h. Denitrification rate constant of the microbes was over one time larger than that of sulfate reduction. When the carbon source was enough (C/N ratio and C/S ratio more than 3), denitrification efficiencies all surpassed 98%, while that of sulfate reduction only reached 84%. Under the same condition, the nitrate reduction ability of microbes was stronger than that of sulfate reduction, and the process of nitrate reduction had much more superiority.