水力条件对复合人工湿地处理城市受污染河水效果的影响

Effect of hydraulic conditions on treatment of polluted river water by hybrid constructed wetlands

通过对水力负荷、水力停留时间等水力条件的控制,观察其对复合垂直上行流人工湿地处理城市受污染河水效果的影响。一年多来的运行结果表明:水力条件对复合垂直上行流人工湿地去除其他污染物的影响显著,但对总氮去除的影响不大。水力停留时间的延长可提高总磷、氨氮、COD的去除效果;随着水力负荷的增加,总磷、氨氮、COD去除率都有所增加,但TN的去除率略有减少。在相对较短的水力停留时间及较高水力负荷条件下,复合垂直上行流人工湿地系统具有良好的污染物去除性能,处理出水中的COD、NH3-N和TP等指标能够达到"城镇污水处理厂污染物排放一级标准"。综合考虑主要污染物的去除效果及经济效益,本项复合垂直上行流人工湿地系统适宜采用的水力停留时间为1 d,水力负荷为0.66 m3/(m2.d)。

The effect of hydraulic conditions on the treatment of polluted river water by the hybrid vertical up-flow constructed wetlands was observed by controlling different hydraulic conditions,e.g.hydraulic loading rate and hydraulic retention time（HRT）.The results of one year operation indicated that hydraulic conditions have significant effect on the removal efficiencies of other pollutants but total nitrogen.It could improve the removal efficiencies of TP,NH3-H and COD by extending the hydraulic retention time,and it was the same as the increasing of hydraulic loading rate,however,the removal rate of TN decreased slightly in this case.Under the conditions of shorter HRT and higher hydraulic loading rate,it can achieve good performance for pollutants removal in this study,the concentrations of COD,NH3-N,and TP in the treated effluent could achieve ＂the Urban Sewage Treatment Plant Pollutant Discharge Class I Standard＂.Comprehensively considering the removal capability for pollutants and economic effect,suitable operation condition of the integrated constructed wetland in this study was suggested as： 1 d of hydraulic retention time,and 0.66 m^3/（m^2·d） of hydraulic loading rate.