4种沉水植物对白洋淀富营养化水体净化效果的研究

Purification efficiency of four species submerged macrophytes for the eutrophic water in Baiyangdian Lake

利用白洋淀富营养化的湖水和底泥与蓖齿眼子菜、马来眼子菜、金鱼藻和黑藻4种沉水植物分别组成室内静态模拟的生长体系,研究4种沉水植物在白洋淀富营养化环境下的生长状况,以及不同沉水植物生长体系对水体磷、氮及有机物的净化效果。结果表明:试验所用沉水植物对富营养化湖水、底泥具有一定的耐受能力,在试验条件中生长良好,长度与生物量都明显增加,并能有效地降低水体中的总磷、氨氮及总氮浓度。试验21 d后,蓖齿眼子菜、马来眼子菜、金鱼藻和黑藻所在的生长体系对水体中总磷的去除能力分别为:4.68、4.72、4.92和5.03μg·d-1·g-1,去除率分别为:83.59%、84.35%、87.84%和89.88%;对水体中氨氮的去除能力分别为:11.42、10.75、12.02和11.90μg·d-1·g-1,去除率分别为:74.98%、70.58%、78.96%和78.11%;对总氮的去除能力分别为:37.69、39.79、42.02和41.65μg.d-1.g-1,去除率分别为:79.40%、83.82%、88.51%和87.73%。沉水植物生长体系对CODcr的降解有所反复,但整体呈现下降趋势。不同沉水植物生长体系总磷、总氮含量随时间降解的拟合方程表明,水体总磷、总氮浓度随时间的变化呈负指数形式衰减。沉水植物对水体营养盐浓度的影响通过多种途径实现,底泥在营养盐的归趋中起着重要的作用。

In order to study the growth of submerged macrophytes and the effectiveness on the removal of phosphorus,nitrogen and organic matter from Baiyangdian Lake,static simulation tests were carried out in lab using water and sediments of Baiyangdian Lake together with four submerged macrophytes（Potamogeton pectinatus,Potamogeton malainus,Ceratophyllum demersum,Hydrilla verticillata）.Selected submerged macrophytes showed considerable tolerance capacity and developed well,associated with higher biomasses under the condition of Baiyangdian Lake,indicating that these macrophytes can effectively remove total phosphorus,ammonium nitrogen and total nitrogen from eutrophic lake.After 21 days,total phosphorus of lake water were reduced with 83.59%,84.35%,87.84% and 89.88% by Potamogeton pectinatus,Potamogeton malainus,Ceratophyllum demersum,Hydrilla verticillata and the ensemble average removal rate were 4.68,4.72,4.92 and 5.03 μg·d-1·g-1,respectively;ammonium nitrogen of water body were reduced with 74.98%,70.58%,78.96% and 78.11% and the ensemble average removal rate per day were 11.42,10.75,12.02 and 11.90 μg·d-1·g-1,respectively;Total nitrogen were reduced with 79.40%,83.82%,88.51% and 87.73% and the ensemble average removal rate per day were 37.69,39.79,42.02 and 41.65 μg·d-1·g-1,respectively.CODcr of water body were reduced repeatedly,but the tendency was reduced.Fitness of TP and TN with time indicate exponentially declining trend.Impacts of submerged macrophytes growth on nutrients in water body were performed in various ways,and sediments is playing an important role in nutrients removal.