4种水生植物在冬季脱氮除磷效果的试验研究

在人工模拟太湖地区冬季的自然条件下,对伊乐藻、菹草、石菖蒲和水芹菜这4种水生植物在不同营养浓度条件下去除氮磷的效果进行了试验研究。结果表明,所选植物都能较好地吸收水中的营养物质。其中水芹菜(挺水植物)和伊乐藻(沉水植物)对环境适应性较强,在相同条件下脱氮除磷的效果也更好,可考虑构成双层次群落结构FA M S用以修复太湖地区富营养化水体。同时发现,植物对氮磷的吸收量随着水中的营养浓度升高而增加,但当浓度超过一定值后,植物的生长受到抑制,导致植物对营养成分吸收量下降,甚至加速水质的恶化。

Removals of Nitrogen and Phosphorus in Taihu Lake Water by Four Hydrophytes in Winter Season

We examined four hydrophytes including Elodea Canadensis Michx. , Potamogeton crispus Linn., Oenanthe javanica (Bl.) DC. and Acorus tatarinowii Schott, capable of decontaminating total nitrogen (TN), total phosphor (TP) NH4-Nand NO3-N at the different nutritional levels during winter period in Taihu Lake. The nutritional levels in the lake were found to be classified as meso-, eutro-, hypertrophic and tolerant concentration, respectively. The results showed that all the hydrophytes studied in our test were capable of absorbing the nutrients substance effectively, but Elodea Canadensis Michx.was stronger than Potamogeton crispus Linn. in the submerged plants, and Oenanthe javanica (Bl.) D C.was better than Potamogeton crispus Linn. in the emerged plants. Adaptabilitiesof both Oenanthe javanica (Bl.) D C. and Elodea Canadensis Michx towards environmental changes and the ability of removing nitrogen and phosphor at a certain condition were very close. Therefore, the both may be used as the two-layer structured FAMS (Floating Aquatic Macrophyte-based Treatment System), able to renovate eutrophication water at Taihu areas and may improve renovated efficiency of hydrophytes at low temperature season. Meanwhile, the absorbing abilities of hydrophytes towards nitrogen and phosphor increased with the enhanced nutrition concentrations. When the concentration exceeded a certain value, the growth of hydrophytes was restrained, resulting in a decrease of absorbing abilities to nutrient substance, and exacerbating water quality. So we should seek a correct concentration for different hydrophytes renovating eutrophication water more effectively.