磷对混养反硝化污泥活性和微生物群落结构的影响

Biological denitrification is now one of the most widely applied techniques to remove nitrogen from the aquatic environment, and mixotrophic denitrification has gained attention as it takes the characteristics of both heterotrophic and autotrophic denitrification. This study investigated the biological denitrification efficiency and the bacterial community structure of sludge sampled from a mixotrophic denitrification reactor, before and after adding a certain amount of phosphate. The results showed that the bacteria have the capability of denitrification even without phosphorus, but the addition of phosphorus could significantly improve the biomass and the denitrification activity. After phosphate was added, the autotrophic and heterotrophic denitrification activity increased to 0.056 mg•(L•min•g)^-1 and 0.232 mg•(L•min•g)^-1 on N/VSS, which was 2.9 and 3.9 times that of the sludge activity before phosphorus addition, respectively. The bacterial community structure illustrated that the denitrifiers increased remarkably from 13.47% to 44.82% and that the dominate bacteria have also changed. Meanwhile, the growth of autotrophic, heterotrophic, and mixtrophic bacteria were all improved significantly after phosphorus was added.