3种负荷对模拟垂直流人工湿地去除氮、磷效果的影响

Effects of three kinds of loads on the removal of TN and TP in a simulated vertical flow constructed wetlands

为探讨水力负荷、有机负荷和悬浮物固体负荷对垂直流人工湿地基质去除氮、磷效果的影响,采用了人工土柱模拟实验的方法,对不同数值的水力负荷、有机负荷(COD)和悬浮固体负荷单因素影响条件下垂直流人工湿地出水中TN、TP的浓度进行了监测。实验结果表明,在3种负荷单一因素影响条件下,垂直流人工湿地处理出水中TN、TP的浓度均随着负荷的增加而增加,即降低水力负荷、有机负荷、悬浮固体负荷均有利于降低垂直流人工湿地处理出水中TN、TP的浓度。当水力负荷为50 cm/d,垂直流人工湿地TP的去除率较高,达到71.52%;当有机负荷为50 g/(m2·d),TN的平均去除率较高,达到41.84%;当悬浮固体负荷为75 g/(m2·d),TP的平均去除率较高,达到92.13%。因此,在水力负荷实验中,当水力负荷为50 cm/d,垂直流人工湿地对氮、磷去除效果较佳;在悬浮固体实验中,当悬浮固体负荷为75 g/m2·d,垂直流人工湿地对氮、磷去除效果较好;在有机负荷实验中,当有机负荷(COD)为50 g/(m2·d),垂直流人工湿地对氮、磷去除效果较好。

Our aim was to explore the effects of the hydraulic loads,organic loads,and suspended-solids load on the removal of TN and TP. This was done in a simulated vertical flow constructed wetland,in which an artificial soil-column simulation experiment was performed to monitor the effluent indexes,（ including TN and TP） under the condition of different hydraulic loads,organic loads,and suspended solids loads. The results obtained by single-factor influence tests showed that the TN and TP concentrations in the treated effluent increased with increased loading. Relatively low hydraulic,organic,and suspended-solids loads were conducive to reducing the concentrations of TN and TP in the effluent. When the hydraulic load was 50 cm / d,a higher TP removal rate could be achieved（ average of 71. 52%）. For the organic load of 50 g /（ m^2·d）,the average TN removal rate was 41. 84%; the SS load 75 g /（ m^2·d）,and the average TP removal rate was 92. 13%. Therefore,from the results of the single-factor influence experiment,the most promising conditions are hydraulic load of 50 cm /d,organic load of 50 g /（ m^2·d）,and suspended solid load of 75 g /（ m^2·d）.