湿地型生态岛的水体净化能力

Water purification ability of wetland ecological islands

在已建成的石驳岸河道中构建生态岛,不但可以改善生态景观效果,还可以提高水体净化能力。将生态岛和湿地技术结合起来,设计了2种生态岛类型:以泥土为基质的常规型生态岛和以砂石为基质的湿地型生态岛,并对2种生态岛的水体交换能力和水体净化效果进行了研究,结果表明:在水体波动条件下,无植物、栽培鸢尾和芦苇的3个湿地型生态岛的水体交换率最高分别达到90.6%、31.0%和84.0%,分别比常规型生态岛高7.8倍、2.6倍和6.8倍;对总磷、总氮、氨氮的平均去除率分别达到37.4%、41.7%和31.6%,比常规型生态岛提高了15.2%、11.7%和8.4%,因此,湿地型生态岛比常规型生态岛具有更好的水体交换能力和水体净化能力。

Construction of an ecological island in stone revetment not only improves the ecological landscape,but also the water purification capacity. In this study,two kinds of ecological islands were designed based on ecological island and combined wetland technologies： a common ecological island with soil as its matrix and a wetland ecological island with sand as its matrix. The water exchange rates and water purification capacities of the two kinds of ecological islands were determined. The results show that in terms of water fluctuation,the highest water exchange rates of the 3 types of wetland ecological islands,with irises,reeds,and no plants,were31. 0%,84. 0%,and 90. 6%,respectively. These rates were 2. 6 times,6. 8 times,and 7. 8 times higher than they were for the common ecological islands under the same conditions. The TP,TN,and NH3-N degradation rates in the 3 types of wetlands reached 37. 4%,41. 7%,and 31. 6%,and were 15. 2%,11. 7%,and 8. 4%higher for the corresponding conditions in the 3 types of common ecological islands. These results indicate that wetland ecological islands have higher water exchange rates and water purification capacities than similarly set up common ecological islands.