Research
| Title： | Microbial nitrogen removal pathways in integrated vertical-flow constructed wetland systems |
|---|---|
| First author： | Hu, Yun; He, Feng; Ma, Lin; Zhang, Yi; Wu, Zhenbin |
| Journal： | BIORESOURCE TECHNOLOGY |
| Years： | 2016 |
| DOI： | 10.1016/j.biortech.2016.01.106 |
| Abstract： | Microbial nitrogen (N) removal pathways in planted (Canna indica L.) and unplanted integrated vertical-flow constructed wetland systems (IVCWs) were investigated. Results of, molecular biological and isotope pairing experiments showed that nitrifying, anammox, and denitrifying bacteria were distributed in both down-flow and up-flow columns of the IVCWs. Further, the N transforming bacteria in the planted IVCWs were significantly higher than that in the unplanted ones (p < 0.05). Moreover, the potential nitrification, anammox, and denitrification rates were highest (18.90, 11.75, and 7.84 nmol N g (1) h (1), respectively) in the down-flow column of the planted IVCWs. Significant correlations between these potential rates and the absolute abundance of N transformation genes further confirmed the existence of simultaneous nitrification, anammox, and denitrification (SNAD) processes in the IVCWs. The anammox process was the major N removal pathway (55.6-60.0%) in the IVCWs. The results will further our understanding of the microbial N removal mechanisms in IVCWs. (C) 2016 Elsevier Ltd. All rights reserved. |
