不同湿地植物的根系泌氧作用与重金属吸收

Root oxygen release and heavy metal uptake of various wetland plants

为研究不同湿地植物根系泌氧能力与重金属吸收积累能力间的关系,选用6种对废水中重金属吸收能力较强的湿地植物进行盆栽实验。结果表明:不同种类湿地植物的根系向水中的泌氧能力存在明显差异,植物间水体溶解氧质量浓度的差异最大可达1.05 mg/L;不同种类湿地植物对重金属的吸收积累能力也有显著差异,而且在重金属积累量方面的差异明显高于重金属浓度方面的差异。相关分析表明:不同种类湿地植物水体溶解氧浓度与植株重金属积累量之间存在显著正相关关系,相关系数达到显著水平(P<0.05)。该结果说明,湿地植物对废水及底泥中重金属的吸收积累能力在相当大的程度上取决于其根系的泌氧能力。

In order to investigate the relationships between root oxygen release ability and heavy metal uptake and accumulation of different wetland plants, a pot experiment was conducted with six kinds of wetland plants with high heavy metal uptake ability. The results showed that there were obvious differences among the wetland plants in root oxygen release ability, and the largest difference between the plants in dissolved oxygen （DO） in pot water was as much as 1.05 mg/L. The variation among the wetland plants in heavy metal uptake was also significant, and the differences in heavy metal accumulation in the plants were larger than the differences in metal concentrations. Relevant analyses indicated that there were significant （ P 〈 0.05） and positive correlations between pot water DO and heavy metal accumulations in the wetland plants. It can be concluded from the results that the abilities of wetland plants for heavy metal uptake from wastewater and sediment are mainly determined by the root oxygen release ability of the plants.