2种人工湿地的水力停留时间及净化效果

以复合垂直流人工湿地(IVCW)和水平潜流人工湿地(HSCW)为研究对象,研究了2种湿地运行的季节性最佳水力停留时间(HRT)参数,并监测了2种湿地在最佳HRT参数下运行时对污水的净化效果。结果显示:(1)在IVCW中,最佳HRT在春、秋季为8～10 h;夏季为6 h;冬季为12 h。在HSCW中,最佳HRT在春、秋季为10～12 h;夏季为6～8h;冬季为24～36 h。(2)2种湿地对COD的去除率均无显著的季节性差异;湿地进水中NH4+-N/TN比值与TN去除率显著负相关;不同季节下IVCW对TN的去除效果均高于HSCW。(3)水温对TN、TP去除率的影响在IVCW中比HSCW中的明显;水温高时,2种湿地中的TN去除率较高,IVCW中的TP去除率也较高,但HSCW中的TP去除率则较低,它们间均未达到显著的相关性。

Hydraulic retention time and purification effect of two kinds of constructed wetlands

Two kinds of constructed wetlands were as the research objects,integrated vertical flow constructed wetland(IVCW) and horizontal subsurface flow constructed wetland(HSCW).The optimum hydraulic retention time(HRT) was studied in the two constructed wetlands in different seasons.The effects of wastewater purification were got when the two constructed wetlands were with the best HRT respectively.The results showed that:(1) The best HRT in IVCW was eight to ten hours in spring and autumn,six hours in summer,twelve hours in winter.The best HRT in HSCW was ten to twelve hours in spring and autumn,six to eight hours in summer,twenty four hours to thirty six hours in winter.(2) The removal efficiency of COD were no significant seasonal variations in the two kinds of constructed wetlands.Between the proportion of NH+4-N/TN(total nitrogen) in the two wetlands’ influent sewerage and TN removal efficiency there was a significant negative correlation.TN removal efficiency in IVCW was higher than that in HSCW in four seasons.(3) The effects of water temperature on removal efficiency of TN and TP in IVCW were more obvious than those in HSCW.When the water temperature of the wetland was high,the TN removal efficiency in the two wetlands and TP removal efficiency in the IVCW were high,whereas the TP removal efficiency in the HSCW was low.There was not obvious correlation between the water temperature and the removal efficiency of TN or TP.