几种植物对潜流型湖滨湿地中氮磷的处理效果比较

湖滨带是连接湖泊水域生态系统与陆地生态系统的一个功能过渡区,是湖泊的最后一道保护屏障。在河流的入湖口建造湖滨湿地,可有效净化入湖水中携带的部分有机污染物、营养盐等。湿地净化污染物的机理极为复杂,其中植被起着重要的作用。选择适当的植物是构建湿地系统的关键。以云南省抚仙湖北岸的湖滨湿地——马料河潜流型湿地为研究对象,探讨了美人蕉(Cannaindica),菖蒲(AcoruscalamusLinn),伞竹(Cyperusalternifolius),香蒲(Typhaelatifolia)四种不同植被系统的潜流型湖滨湿地去除污水中营养盐的效果,为抚仙湖湖滨带人工湿地的合理优化选择植物提供一定的依据。结果表明,四种植被系统的潜流湿地对总氮和总磷均有一定的去除效果。但是由于湿地长期运行而疏于管理,植物没有定期收割翻新,四种植物的氮磷去除率差别不太大,去除效果均不太佳。其中,美人蕉对总氮和总磷的去除效果较好,其去除率分别是30.4%,19.13%,其次为香蒲和伞竹,效果较差的是菖蒲。并且实验表明,暴雨对四种植物湿地氮的去除效果有很大的影响。连续几天的暴雨情况下,四种植物系统氮的去除率都很低。

Comparison of removal effect of several macrophytes on nitrogen and phosphorus in subsurface-flow wetlands of riparian zone

The riparian zone is a functional transition region, the last protection barrier of lakes, which is connected the lake aquatic ecosystem and the terrestrial ecosystem. Building lakeside wetland in the riparian zone can decontaminate some organic pollutants and nutrients of water body effectively. As the mechanism purifying the pollutants in the wetland is complex, the vegetation plays an important role. Selecting appropriate macrophytes is where the shoe pinches of building the systems of wetlands. The subsurface wetlands of River Maliao, the lakeside wetlands at the northern bank of Fuxian lake in Yunnan province, has been selected as the research subject. And the removal effect of four different macrophyte systems, cannas (Canna indica), calamus (Acorus calamus Linn), Umbrella Plant (Cyperus alternifolius), cattails (Typhae latifolia), on total nitrogen and total phosphorus from the sewage in subsurface flow lakeside wetlands has been studied, the purpose of which is that some guidance is given for selecting macrophyte reasonably in the constructed wetlands of riparian zone of Lake Fuxian. The results showed that, there was some removal effect for the total nitrogen and total phosphorus in all the subsurface wetlands of four different macrophyte systems. But due to lack of management and periodic harvesting to the plants after long-term operation, the difference of the removal efficiency of four different macrophyte systems is not distinct. And the removal effect of all four macrophyte is not well. Of all, the removal effect of phosphorus and nitrogen by cannas was better than others. The removal efficiency of nitrogen and phosphorus were 30.4% and 19.13%, respectively. And the next were cattails and Umbrella Plant. The removal effect of calamus was the worst. And experiences also showed that, there was great influence of rainstorm on total nitrogen in four macrophyte wetlands. Under such conditions of several days of continuous rainstorm, the removal efficiency of total nitrogen of four different macrophyte systems was low.