Research
| Title： | Bacterial community and nitrate removal by simultaneous heterotrophic and autotrophic denitrification in a bioelectrochemically-assisted constructed wetland |
|---|---|
| First author： | Xu, Dan; Xiao, Enrong; Xu, Peng; Lin, Lili; Zhou, Qiaohong; Xu, Dong; Wu, Zhenbin |
| Journal： | BIORESOURCE TECHNOLOGY |
| Years： | 2017 |
| DOI： | 10.1016/j.biortech.2017.09.045 |
| Abstract： | To enhance nitrate removal in constructed wetlands (CWs), a bioelectrochemically-assisted CW (BECW) integrating a three-dimensional biofilm-electrode reactor (3D-BER) into the CW was evaluated for the effectiveness of combined autotrophic and heterotrophic denitrification in the presence of organic matter and applied current. The effects of COD/N ratios on nitrate removal were investigated, and the bacterial communities in the granular active carbon (GAC) and graphite felt (GF) in the reactor's cathode region were compared. The highest NO3--N and TN removal efficiencies of 91.3 +/- 7.2% and 68.8 +/- 7.9% were obtained at the COD/N ratio of 5. According to the results of high-throughput sequencing analysis, sample GAC was enriched with a high abundance of Pseudomonas (17.29%) capable of autotrophic and heterotrophic denitrification, whereas autotrophic bacteria Thiobacillus (43.94%) was predominant in sample GF. The synergy between heterotrophic and autotrophic denitrification bacteria is believed to cause the high and stable nitrogen removal performance. |
