高水力负荷下人工湿地处理污水厂尾水的研究

Study on Treatment of Municipal Sewage Plant Effluent by Constructed Wetland at High Hydraulic Load

为了减少人工湿地的占地面积,采用水平潜流人工湿地在高水力负荷下对污水厂一级A出水进行处理。实验结果表明,随着高水力负荷的降低,湿地系统对污染物的平均去除率逐渐增加,但对污染物的平均去除量却在水力负荷最高时达到最大值。其中在水力负荷为0. 5 m^3/m^2·d时,湿地系统对BOD5、氨氮、总氮和总磷的平均去除率达到最大,分别为74. 6%、52. 2%、51. 1%、53. 3%;在水力负荷为1. 2 m^3/m^2·d时,湿地系统对BOD5、总氮和总磷的平均去除量达到最大,分别为2. 3 g/d、0. 6 g/d、0. 08 g/d。通过分析得出在高水力负荷人工湿地中水力停留时间是污染物去除效果的限制因素。

In order to reduce the occupied land of constructed wetland,the horizontal subsurface flow constructed wetland was used to treat the grade A effluent of wastewater treatment plant at high hydraulic load.The experimental results showed that the average removal rate of pollutants in wetland system gradually increased with the decrease of hydraulic load.But the average removal of pollutants reached the maximum when the hydraulic load was the highest.The average removal rates of BOD5,ammonia nitrogen,total nitrogen and total phosphorus reached the maximum of 74.6%,52.2%,51.1%and 53.3%respectively at the hydraulic load of 0.5m3/m2·d.When the hydraulic loading was 1.2 m3/m2·d,the average removal of BOD5,total nitrogen and total phosphorus in wetland system reached maximum at 2.3g,0.6g and 0.08g respectively.In addition,it was concluded that hydraulic retention time in constructed wetland of high hydraulic load was the key factor affecting the removal efficiency of pollutants.