五种沉水植物对富营养化水体的净化效果

Effects of five submerged macrophytes on the purification of eutrophication water

为达到净化水质的目的,采用移栽沉水植物控制富营养化水体中营养盐含量和浮游藻类生物量。本研究在夏季藻类密度较高的富营养化水体中移栽5种长江中下游流域常见沉水植物,比较不同沉水植物去除营养盐和控制藻类总量的能力。研究结果:5种沉水植物对水体总氮含量去除率的大小顺序为:竹叶眼子菜>黑藻>苦草>微齿眼子菜>菹草,对总磷去除率大小顺序为:竹叶眼子菜>黑藻>微齿眼子菜>苦草>菹草;竹叶眼子菜控制水体中藻类总量的效果最佳,苦草、微齿眼子菜及菹草次之,黑藻对水体总磷和浮游植物的去除效果均极显著(p≤0.01),而对总氮含量的作用影响不明显(p=0.209)。综合营养盐吸收作用和藻类控制效果来看,竹叶眼子菜在整个实验过程中生长状态良好并达到较为稳定的净化作用,是夏季治理浅型富营养化静水水体的理想物种之一。

In order to purify the freshwater of eutrophication, submerged plants were used to decrease the nutrient concentrations and phytoplankton. In this study, five common submerged plants in Yangtze River Basin were transplanted to algae-based water in summer. The capacity of eliminating total nitrogen and phosphorus concentrations and decreasing phytoplankton was observed and compared. Results showed that the removal rate of total nitrogen concentration was in the order of Potamogeton malaianus〉Hydrilla verticillata〉Vallisneria natans〉Potamogeton maackianus〉Potamogeton crispus. While the removal rate of total phosphorus was listed as P malaianus〉H, verticillata〉P maackianus 〉V. natans 〉P crispus. In addition, P. malaianus had the best effect on controlling the total amount of algae; while V. natans, P.maackianus and P crispus had less effect on controlling the total amount of algae. H. verticillata could significantly remove the total phosphorus and phytoplankton （p〈0.01）, but it had no obvious effect on the absorption of total nitrogen in water （p=0.209）. Based on the absorption rate of total nitrogen and phosphorus concentrations, as well as removal rate of algae, it can be seen that P. malaianus can grow well and have a stable effect on water purification during the whole experimental period. So it can be considered as a potential plant species to purify small eutrophic water in summer.