乡土水生植物对富营养化水体的净化效果研究

为了解乡土水生植物净化富营养化水体的效果,研究了广东地区5种乡土水生植物对2种富营养化水体总氮(TN)、总磷(TP)的净化效果和植物的生长状况。结果表明,与无植物空白相比,5种乡土植物使低、高浓度水体的TN去除率分别提高了3.8%～13.3%和13.2%～17.1%,TP去除率分别提高了15.2%～22.1%和11.3%～57.6%,其中野荸荠(Eleocharis plantagineiformis)适用于净化低氮水体;酸模叶蓼(Polygonumlapathifolium)适用于高氮水体;三白草(Saururuschinensis)适用于低磷水体;菱角(Trapa komarovii)适用于低氮或高磷水体;水龙(Ludwigia adscendens)对2种水体均有较好的净化效果,对高磷水体效果极佳。5种乡土植物在低、高浓度水体中均旺盛生长,水龙的生物量净增长率分别达375.5%和539.8%,表现最优,其次为菱角;水葫芦(Eichhorniacrassipes)则在高浓度水体中腐烂死亡,加重了水体污染。水龙、菱角对污染物的吸收作用较强,对P的吸收能力显著优于其他植物(P0.05)。因此,5种乡土植物均可作为广东地区富营养化水体修复的备选植物,其中水龙和菱角的开发潜力最大。

Purification of Eutrophic Water by Native Aquatic Plants

In order to understand the purifying effect of native aquatic plants on eutrophic water, five representative native aquatic plants in Guangdong Province were selected with Eichhornia crassipes as a control for studying the removal rate of total nitrogen (TN), total phosphorus (TP), and the growth and absorption ability of six plants in two kinds of eutrophic water were also studied. The results showed that the TN removal rate of 5 native plants in low and high polluted water increased 3.8%-13.3% and 13.2%-17.1% compared with the blank control, while TP removal rate increased 15.2%-22.1% and 11.3%-57.6%, respectively. Eleocharis plantagineiformis was suitable for purifying low nitrogen water, while Polygonum lapathifolium for high nitrogen water. Saururus chinensis was suitable for low phosphorus water, while Trapa komarovii for low nitrogen or high phosphorus water. Ludwigia adscendens was suitable for the two kinds of eutrophic water and had excellent purification effect for high phosphorus water. All 5 native plants could grow vigorously in low and high eutrophic water and the net growth rate of biomass of Ludwigia adscendens reached up to 375.5% and 539.8%, respectively, showing the best, followed by Trapa komarovii. But the control plant Eichhornia crassipes decayed and died under high polluted water, which aggravated water pollution. Ludwigia adscendens and Trapa komarovii had perfect absorption effect on pollutants, and the TP absorption capacity was better than that of other plants (P<0.05). So, it was suggested that all of five native plants could be used as alternative plants for the restoration of eutrophic water in Guangdong, among them Ludwigia adscendens and Trapa komarovii had excellent development potentiality.