两种多裂叶型沉水植物组合净化富营养水体氮磷的对比实验研究

COMPARISON OF NITROGEN AND PHOSPHORUS REMOVAL OF EUTROPHIC WATER BY THE MOSAIC TREATMENT SYSTEM OF TWO PIONEER DISSECTED-LEAF SUBMERGED PLANTS

水生植物组合净化技术被认为比单一物种净化富营养化水体的效果更佳的技术方法。以2种多裂叶型沉水植物先锋种(金鱼藻和穗花狐尾藻)的镶嵌组合方式开展了富营养水体氮磷消减潜力的对比实验研究。结果表明,沉水物种组合试验中所选的沉水植物先锋种均在富营养化水体(氮磷含量达Ⅴ类水质)中生长良好,且对TN、NO_3^--N、TP、PO_4^(3-)-P都有明显的去除效果,去除率均明显高于无沉水植物的两个空白对照组。在选用沉水植物最优种植密度(3g/L)时,种植模式为金鱼藻∶穗花狐尾藻=1∶2的组合对富营养化水体净化效果更佳,其TN去除率达到79.16%,NO_3^--N去除率达到92.47%,TP去除率达到92.08%,PO_4^(3-)-P去除率达到98.39%。

Eutrophication is one of serious ecological problems in the world.As one of eight groups of lakes,lakes in the middle and lower reaches of Yangtze River were in the process of severe eutrophication and degradation of ecosystem function in past thirty years,and need to restore in the systematic ways.At present,ecological restoration by using aquatic macrophytes becomes an applicable and important technology in the control of shallow lake eutrophication.Meanwhile,selection on suitable species of submersed macrophytes to achieve the results desired in the littoral and open-water zones of shallow lakes and to ensure long-term eco-safety and-stability is still an essential but unsubstantial link in the process of lake rehabilitation.In addition,combination of several selected submersed plants in nutrient removal of eutrophic waters is always considered as a better way than single species.In the present study,two pioneer dissected-leaf submersed plants were chosen to conduct the comparison experiment and the dynamic simulation on removal of nitrogen and phosphorus in eutrophic water.Results showed that the two submersed plants grew well during the treatment period,the removal of TN、NO_3^--N、TP、PO_4^(3-)-P in eutrophic water were significantly higher than the control without plants.When the optimal planting density(3g/L)was employed in the experiments,the removal rates of TN、NO_3^--N、TP、PO_4^(3-)-P in eutrophic water were up to 79.16%,92.47%,92.08% and 98.39%,respectively,in the combination treatment group of Ceratophyllum demersum and Myriophyllum spicatum(1∶2).