不同盐沼湿地类型脱氮除磷效能及影响因素分析

采用沉水植物表面流湿地(沉水组)、挺水植物表面流湿地(挺水组)和浮床湿地(浮床组)3种盐沼湿地对长江口近岸低污染水体进行脱氮除磷效能的研究。结果表明,HRT为3 d时,水组、挺水组、浮床组对NO3^--N的去除率在高温时段分别为79.9%±13.2%、71.8%±15.2%、77.2%±13.2%,中温时段分别为39.4%±13.7%、31.5%±8.5%、18.4%±16.6%,低温时段分别为15.6%±14.6%、19.7%±8.6%、2.%5±8.6%。沉水组和挺水组对TP的去除率受温度影响较小,分别为66.4%±32.4%、55.5%±29.4%;而浮床组除磷效果受温度影响较大。当HRT缩短为1.5 d时,3组湿地系统在高温时段仍可达到相近的脱氮除磷效果,在中低温时段脱氮除磷效果都有不同程度的下降。

Analysis on Efficiency and the Influencing Factors of Nitrogen and Phosphorus Removal in Different Salt Marsh Wetland Types

Study on the nitrogen and phosphorus removal effects in the low-pollution water bodies in the Yangtze River estuary was carried out by using three kinds of salt marsh wetlands,which were submerged plant surface wetland(Chenshui Group),emergent plant surface wetland(Tingshui Group)and floating bed wetland(Fuchuang Group).The results showed that,when HRT was 3 d,the removal rates of NO3--N in Chenshui Group,Tingshui Group and Fuchuang Group at high temperature were 79.9%±13.2%,71.8%±15.2%,and 77.2%±13.2%,respectively,and at mid-temperature periods were 39.4%±13.7%,31.5%±8.5%,and 18.4%±16.6%,respectively,and at low temperature periods were 15.6%±14.6%,19.7%±8.6%,and 2.5%±8.6%,respectively.The removal rates of TP in Chenshui Group and Tingshui Group were less affected by temperature,which were 66.4%±32.4%and 55.5%±29.4%,respectively,while the Fuchuang Group was greatly affected by temperature.When the HRT was shortened to 1.5 d,three groups of wetlands could still achieve similar nitrogen and phosphorus removal effects at high temperature,and nitrogen and phosphorus removal in the low and middle temperature periods reduced to varying degrees.