Impact of Starvation Conditions on Biological Community Structure in Sulfur Autotrophic Denitrification Reactor

Abstract

Sulfur/dolomite and pyrite/dolomite autotrophic denitrification reactors were applied to treat the secondary effluent of wastewater treatment plant to explore the removal effect, the changes of microbial community, and recovery time of reactors after starvation period. It was shown in the results that after 30 d non-water starvation endurance, the effluent concentrations of NO3--N in sulfur/dolomite and pyrite/dolomite reactors increased from 1.78 mg·L-1, 11.32 mg·L-1 to 27.87 mg·L-1, 26.56 mg·L-1 respectively at the low temperature of 12-14℃. In addition, sulfur/dolomite and pyrite/dolomite reactors recovered within 5 d and 11 d since restarted and could maintain a good effect of nitrogen removal at low temperature. MiSeq high throughput sequencing results showed that the abundance and diversity of the bacterial communities in starvation period in both reactors were lower than those in recovery period. The dominating phylum was Proteobacteria in both reactors while the dominating class was β-Proteobacteria. Thiobacillus was identified as the main genus for denitrification in sulfur/dolomite reactor.