低温下浮水植物型表面流人工湿地中有机氮的去除

在以有机氮(ORN)为主要氮组分的富营养化水体中,采用批量培养方式对比研究了水温为6.8～7.2 ℃时浮水植物系统(水葫芦和浮萍)、泡沫板系统(无生命覆盖系统)及空白系统(无覆盖物系统)中氮组分的转化与去除,并探讨了水温为9.5～13.1 ℃时水葫芦系统中不同起始ρ(COD_Cr) (27～148 mg/L)对污染物去除的影响. 结果表明:不同系统对比试验中,水葫芦和浮萍系统ORN的去除率分别为83%和63%,总氮(TN)的去除率分别为50%和59%,高于泡沫板系统(ORN去除率为39%,TN去除率为39%)和空白系统(ORN去除率为48%,TN去除率为43%),2种植物系统中COD_Cr的去除率分别为75%和54%,与空白系统(63%)相差不大,但高于泡沫板系统(38%). 随着起始ρ(COD_Cr)的提高,水葫芦系统中水体缺氧状况加剧,ORN去除率由85%下降到66%,同时TN去除率由19%提高至45%. 

Study on Organic Nitrogen Removal in Floating-Plant-Type Surface Flow Constructed Wetland at a Low Water Temperature

The eutrophic water body with organic nitrogen(ORN) being the main component of nitrogen was studied.The batch cultivation method was adopted to comparatively investigate the transform and removal of nitrogen components in two floating-plant systems(including hyacinth and duckweed systems),foamy board system and control system,at a low water temperature of 6.8～7.2 ℃.The effect of initial COD_Cr levels(27～148 mg/L) at a water temperature of 9.5～13.1 ℃ was also discussed.Results indicated: in the two floating-plant systems,ORN removal rate was 83% and 63% respectively,while total nitrogen(TN) removal rate was 50% and 59% respectively,which were higher than that in the foamy board system(ORN: 39%,TN: 39%) and the control system(ORN: 48%,TN: 43%).COD_Cr removal rate in the two plant systems was 75% and 54% respectively,almost the same as that in the control system(63%) but higher than that of foamy board system(38%).With the increase of initial COD_Cr level,followed by the decrease of DO,in hyacinth system ORN removal rate decreased from 85% to 66% while TN removal rate increased from 19% to 45%.