Improvement of water quality through biological denitrification.

The present study was undertaken to observe the effect of biological denitrification process on water quality parameters. The results obtained in the present investigations show that the value of pH and alkalinity was increased due to generation of alkalinity during biological denitrification process. The obtained value of the DO in the treated water was found lower than the supplied water, which indicates, DO was consumed by the bacterium. The COD of the treated water was nil, which shows that the organics have been consumed by the bacterium during the denitrification process. The biological reduction of nitrate-nitrogen (from 50.79 mg/L to 0.57 mg/L) was found to be lower than the tolerance limit prescribed by WHO without changing the water quality.