8种挺水植物对污染水体的净化效果比较

Effect on polluted water purification by eight emergent plants

通过室外盆栽实验，研究了8种挺水植物在不同水力停留时间对污染水体的净化效果。结果表明各实验植物对COD、NH4—N、TN和TP的去除率随水力停留时间的延长而增加。水力停留时间为5d时，除三棱草（Sparganim stenophyllum Maxim．）外，其它植物对C01）均有明显的去除效果，其中，菖蒲（Acorus calamus L.）、水葱（Scirpus validus Vahl.）、宽叶香蒲（Typha latifolia L．）及黄花鸢尾（Iris wilsonii C．H．Wright）去除COD的效果较好，去除率达到90％左右。水力停留时间为7d时，与无植物空白相比，各植物其NH4＋-N和TN去除率分别提高15．0％～41．8％和6．7％～25．1％，其中宽叶香蒲、茭白和黄花鸢尾对NH4＋—N和TN的去除性能尤为突出。8种植物中，茭白（Zizania latifolia Turcz．）和宽叶香蒲TP去除性能较好，其TP去除率分别提高10．8％和11．2％，其余6种植物的TP去除率与对照之间均无显著差异。综合分析，宽叶香蒲、茭白和黄花鸢尾可作为南四湖人工湿地备选植物。

Pot-culture experiments were conducted to study the effects of eight emergent plants on purifying polluted water under different hydraulic retention times. Results showed that the purifying effects on pollutants were different among eight emergent pla- nts and removal efficiency increased with hydraulic retention time. All plants had significant improvement for COD removal except Sparganium stenophyllum Maxim, when hydraulic retention time was 5 days. The COD removal efficiencies of Acorus calamus L., Scirpus validus Vahl, Typha latifolia L. and Iris wilsonii C. H. Wright were all about 90%, which were higher than those of the other plants. When the hydraulic retention time was 7 days, the removal efficiencies of eight plants for NH4＋ -N and TN increased by 15.0 % - 41.8 % and 6.7 % - 25.1% respectively as compared with the control, lris wilsonii C. H. Wright, Zizania latifolia Turcz. and Typha latifolia L. showed excellent removal capacities of NH4＋ -N and TN. TP removal efficiencies by Zizania latifolia Turcz. and Typha latifolia L. were significantly higher than that of control, the increased removal efficiencies for TP were 10.8% and 11.2% respectively. These results indicated that Iris wilsonii C. H. Wright, Zizania latifolia Turcz. and Typha latifolia L. could be selected for constructing wetland hydrophytes in Nansi Lake.