垂直流人工湿地中污染物的沿程变化

Changes of Pollutants Concentration at Various Depths in Vertical Flow Constructed Wetland

以垂直流湿地处理生活污水为例,通过对两种垂直流湿地中不同深度填料中水样的分析,讨论了5个水力负荷条件下,CODCr、NH4+-N、TN、NO3--N浓度的沿水流方向变化。结果表明,水力负荷为8.5、10.6、14.1cm·d-1时,多层填料(1#)湿地和双层填料(2#)湿地中的CODCr浓度均沿程降低,在0～20cm浅层填料处,即可去除绝大部分的有机污染物。1#湿地和2#湿地中NH4+-N、TN、NO3--N浓度的沿程变化在不同的水力负荷条件下差异较大。比较分析表明,垂直流湿地的填料结构和水力负荷影响硝化和反硝化反应的进程,从而影响氮污染物的沿程变化。

Two lab plants of vertical flow constructed wetland were used to treat sewage at hydraulic loading rates of 8.5, 10.6, 14.1, 21.2 and 42.4 cm·d^-1 respectively. The wastewater was fed continuously, in order to find out the change rules of pollutants concentration, 5 sampling locations were set at various depths of the constructed wetlands. The results showed that the changes of CODCr concentration were similar between muhilayer substrate （1#） wetland and dual-substrate （2#） wetland, and CODCr concentration reduced in the flow direction. A majority of CODCr were removed at 0-20 cm depth of the two wetlands. The change rules of NH4^＋-N, TN, NO3^--N concentration in the flow direction had significant differences between 1# wetland and 2# wetland at hydraulic loading rates of 21.2 cm·d^-1 and 42.4 cm·d^-1, implying that the substrate structure and hydraulic loading rate affected nitrification and denitrifieation.