Journal of Ecology and Rural Environment ›› 2021, Vol. 37 ›› Issue (8): 962-971.doi: 10.19741/j.issn.1673-4831.2020.0933

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Research Progress on Nitrogen Removal from Low Pollution Water by Different Types of Constructed Wetlands

LI Rong-tao1,2, YANG Ping-guo1, LI Lin-lin2,3, LU Shao-yong2, DU Zhi-chao2,4, KONG Wei-jing2   

  1. 1. College of Life Sciences, Shanxi Normal University, Linfen 041000, China;
    2. State Environmental Protection Scientific Observation and Research Station for Lake Dongting/National Engineering Laboratory for Lake Pollution Control and Ecological Restoration/State Environmental Protection Key Laboratory for Lake Pollution Control, Chinese Research Academy of Environmental Sciences, Beijing 100012, China;
    3. College of Water Sciences, Beijing Normal University, Beijing 100875, China;
    4. School of Civil Engineering, Liaoning Engineering Technology University, Shenyang 123000, China
  • Received:2020-11-23 Online:2021-08-25 Published:2021-08-27

Abstract: Low-pollution water has the characteristics of wide sources, large water volume, strong fluctuation of water quality and quantity, and relatively low concentration of pollutants. Constructed wetland is an effective measure to treat low-polluting water. In this paper, the oxygen increasing mechanisms of two typical oxygen-enhanced constructed wetlands, i.e. tidal flow constructed wetlands and aerated constructed wetlands, for nitrogen removal from low pollution water were described, and their denitrification effects and the influencing factors were analyzed. The results show that in the tidal flow constructed wetland, proper idle time and submerged reaction time can create good aerobic-anaerobic conditions, which is beneficial to the removal of TN; when the operating cycle to be less than 24h, and the submerged ~idle time ratio to be between 0.25-4 and 0.5-7, the wetland would have the best NH3-N and TN removal effect in low-polluted water. Reasonable aeration can make the constructed wetland to maintain a high pollutant removal rate at low temperature (-5-10℃); for the treatment of low-polluted water by aeration constructed wetland, the best air-water ratio is 6:1, and the best aeration part is the bottom of the wetland. In addition, by comparing the denitrification effects of the two constructed wetlands, it shows that the treatment effect of aerated constructed wetlands on the removal of NH3-N and TN was better than that of the tidal flow constructed wetlands, but the treatment effect of COD removal was weaker than that of tidal flow constructed wetlands. Finally, this article also points out the existing problems in the denitrification of low-polluted water in the two constructed wetlands. The results of this study could be used as a reference for similar further researches.

Key words: tidal flow, aerated, constructed wetland, low pollution water, nitrogen

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