Huang Juan, Wang Shi-he, Yan Lu, Liu Yang, Wang Feng
Department of Municipal Engineering, Southeast University, Nanjing 210096, China.
Huan Jing Ke Xue. 2007 Sep;28(9):1965-9.
To reveal the nitrogen purification mechanism in subsurface-flow constructed wetlands, nitrification and denitrification intensities were studied in reed, canna and unplanted wetlands respectively. The results show that nitrification intensity in subsurface-flow wetlands is remarkably influenced by temperature and closely correlative with total and ammonia nitrogen removal efficiency. It appears in upright direction that nitrification and denitrification intensities in upper layer are higher than that in the lower. For the reed wetland, nitrification intensity is low in both ends but high in the middle of upper layer, while it decreases gradually along distance in lower layer. The change of denitrification intensity along distance is not obvious. Average nitrification intensity is higher in vertical-flow wetland than that in horizontal-flow wetlands, higher in planted wetlands than that in unplanted wetland and higher in reed wetland than that in canna wetland. The secretion from plant roots directly results in the gradual decrease of nitrification intensity in plant rhizosphere. Results also show that intensity of denitrification is obviously higher than that of nitrification. Thereby, subsurface-flow wetland has strong denitrification potential.
为揭示潜流人工湿地的氮净化机制，分别对芦苇、美人蕉和无植物湿地的硝化和反硝化强度进行了研究。结果表明，潜流湿地的硝化强度受温度影响显著，且与总氮和氨氮去除效率密切相关。上层的硝化和反硝化强度在垂直方向上高于下层。对于芦苇湿地，上层两端的硝化强度较低，中间较高，而下层则沿距离逐渐降低。反硝化强度沿距离的变化不明显。垂直流湿地的平均硝化强度高于水平流湿地，有植物湿地高于无植物湿地，芦苇湿地高于美人蕉湿地。植物根系分泌物直接导致植物根际硝化强度逐渐降低。结果还表明，反硝化强度明显高于硝化强度。因此，潜流湿地具有较强的反硝化潜力。
