湿地植物对城市雨水径流污染的净化效能与适应性研究

Study on purification efficiency and adaptability of wetland plants for urban runoff pollution

通过灯芯草、千屈菜、菖蒲、梭鱼草的雨水径流水培试验,研究了湿地植物对城市径流主要污染物COD、TN、TP及重金属的净化效能,分析了植物对径流污染物的耐受性和适应性。结果表明:植物对重金属的净化效能良好;千屈菜对COD的耐受性及去除率差,当COD≥1 160 mg/L会导致其死亡;灯芯草对pH值的适应力差,酸雨会严重影响其水处理效果及长势;当pH<6时菖蒲和梭鱼草对径流TP的处理能力相当;对TN<20 mg/L的雨水径流,菖蒲对TN的去除效率达93%以上优于梭鱼草,且菖蒲对径流COD的去除效果及适应性好于其他三种植物,是较适宜的雨水径流湿地植物。

Through hydroponics experiment of Juncus effusus, Lythrum salicaria, Acorus calamus and Pontederia cordata with urban runoff, the paper studied the purification efficiency of wetland plant for main pollutants of urban runoff, such as COD, TN, TP and heavy metal and analyzed the tolerance and adaptability of the plants on runoff pollutants.The results showed that the purification efficiency of the plants for heavy metal is satisfactory.The tolerance and removal rate of Lythrum salicaria on COD are quite low, the plant will lead to death when COD concentration is beyond 1160 mg/L.Juncus effusus has poor adaptability to pH, therefore, the acid rain might exert a severe effect on the treatment efficiency and growth of Juncus effusus.The treatment capacity of Acorus calamus and Pontederia cordata on runoff TP is almost the same when pH values is below 6.When TN in the runoff is less than 20 mg/L, the TN removal efficiency of Acorus calamus is higher than 93%and better than that of Pontederia cordata.The COD removal efficiency and adaptability of Acorus calamus are also better than those of other three alter-natives.So ,Acorus calamus is a suitable wetland plant for urban runoff.