[Study on denitrification using different carbon sources]

In this study, bench scale tests were conducted to study the potentials of immobilized denitrifier to reduce nitrate in the presence of 4 different carbon sources: glucose, cane sugar, methanol and acetic acid. The results showed that the carbon sources can be used by the immobilized bacteria as exogenous carbon sources. While using methanol, the average denitrifying velocity was lower than the others. Dissimilatory reduction to ammonium was not significant and accounted for less than 5% of reduced nitrate. By a 6-hour hydraulic residence time, the denitrification rates were higher than 96%. The nitrate enriched water of S lake was also treated by the immobilized denitrifier to study the character of denitrification, especially on the using of natural carbon sources as electron donotor. The results showed that more than 90% of the nitrate in the water could be reduced by the immobilized bacteria, and more than 20% of the natural carbon sources in the water could be used by the immobilized cells.