Nitrogen and phosphorus removal performance and bacterial communities in a multi-stage surface flow constructed wetland treating rural domestic sewage.
Xi Li, Yuyuan Li, Dianqing Lv
Dec 20, 2019
Citations
53
Citations
Journal
The Science of the total environment
Full text
Semantic Scholar
Key Takeaway Key Takeaway: Multi-stage surface flow constructed wetlands effectively remove nitrogen and phosphorus from rural domestic sewage, promoting bacterial diversity and changing bacterial communities in the sediment.
Abstract
A multi-stage surface flow constructed wetland (SFCW) is used to treat decentralized rural domestic sewage. The performance of a multi-stage SFCW located in Hunan, China, and the associated microbial community structures were investigated. The average removal rates of the multi-stage SFCW planted with Myriophyllum elatinoides were 1.0 g m-2 d-1, 0.84 g m-2 d-1, 61.3 mg m-2 d-1, and 85.3 mg m-2 d-1 for total nitrogen (TN), ammonia (NH4+), nitrate (NO3-), and total phosphorus (TP), respectively. Furthermore, the sediment and presence of plants were found to be important for the removal N and P. The average removal rates by sediment and plants were 196.6 mg N m-2 d-1 and 49.9 mg P m-2 d-1, 17.6 mg N m-2 d-1 and 8.1 mg P m-2 d-1, respectively. The microbial community profiles demonstrated that Proteobacteria, Chloroflexi, Bacteroidetes, Firmicutes and Euryarchaeota were the predominant phyla in each stage and at different sampling times. The concentrations of NO3-, TP, TN, and NH4+, and the pH of the sediment and water had a significant effect on the presence of denitrifying bacteria in the anaerobic environment. Whereas, dissolved oxygen (DO) and redox potential (Eh) had a significant effect on the presence of nitrifying bacteria in the aerobic environment. This research strongly supports that the use of the multi-stage SFCW promotes bacterial diversity and changes bacterial community in the sediment.