3 种挺水植物吸收水体NH4+、NO3-、H2PO4- 的动力学特征比较

Comparisons of NH4+, NO3- and H2PO4- uptake kinetics in three different macrophytes in waterlogged condition

  • 摘要: 本文用动力学试验研究了具有景观价值的3 种挺水植物—— 水生美人蕉(Canna generalis)、细叶莎草(Cyperus papyrus)、紫芋(Colocasia tonoimo)对H2PO4-、NH4+、NO3- 的吸收特征及差异。试验结果表明: 3 种挺水植物吸收H2PO4- 时, 美人蕉的吸收速率最快, 且在较低离子浓度条件下也可以吸收该离子, 说明其具有嗜磷特性, 能够适应广范围浓度H2PO4- 环境; 吸收NO3- 时, 细叶莎草的速率最快, 但对低浓度NO3- 环境的适应能力较差, 美人蕉吸收NO3- 的特性与细叶莎草刚好相反; 吸收NH4+ 时, 细叶莎草的吸收速率最快, 且在低浓度NH4+ 环境下仍能吸收该离子, 而美人蕉的吸收速率最慢, 但能在低浓度NH4+ 环境下吸收该离子。说明不同植物对养分的吸收特性存在较大差异, 各自的污染水体修复适用范围也不同。美人蕉可用于各种浓度H2PO4- 污染的水体修复; 而NO3- 污染严重的水体最适宜用细叶莎草作先锋植物, 修复到一定程度后再种植美人蕉来维持水质; 细叶莎草在各种浓度NH4+ 污染的水体中均适用, NH4+ 污染较轻的水体也可用美人蕉修复。

     

    Abstract: In a kinetic experiment, the absorption of NH4+, NO3- and H2PO4- by three different emergent macrophytes (Canna generalis, Cyperus papyrus, Colocasia tonoimo) in waterlogged condition were analyzed in relation to values of landscape esthetics and economic value. Based on the analysis, the uptake rate of H2PO4- was highest in C. generalis. In fact, C. generalis continued to absorb H2PO4- in even low ion concentration conditions. This suggested that C. generalis successfully coped with a wide range of H2PO4- concentration. On the other hand, the uptake rate of NO3- was highest in C. papyrus. It was, however, not able to successfully adapt to low nutrient conditions (as C. generalis). The highest uptake rate of NH4+ was also in C. papyrus, and even of low concentrations of NH4+. Also, NH4+ absorption was lowest in C. generalis. The application scope of three plants on restoration of polluted water varied with ion absorption characteristics of the plants. C. generalis did generally well in all levels of H2PO4- polluting water. C. papyrus, on the other hand, was only suitable for pre-treatment of seriously NO3- polluting water. Then C. generali was usable in maintaining water quality after improvement to a certain degree. C. papyrus was applicable in various concentrations of NH4+ polluting water. C. generalis grew better in water environments that were less polluted by NH4+.

     

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