几种植物对城市尾水中重金属的去除效果研究

为了筛选适合吸收城市尾水中重金属的植物品种,研究了酸模(Rumex acetosa L.)、莎草(Cyperus glomeratus L.)和空心菜(Ipomiea aquatica Forsk)3种植物对城市尾水中重金属Zn、Cu、Pb和Cd的去除效果,并以酸模为材料,研究其对人工模拟重金属Cd和Pb污染水体的适应性。结果表明:酸模、莎草、空心菜3种植物对城市尾水中Zn、Cu、Cd、Pb的去除率分别为74.33%、60.43%、45.45%、36.43%,其中酸模对重金属的去除效果最好,其次是莎草和空心菜。酸模对尾水中Zn、Cu、Cd、Pb的去除率分别达到了86.63%、90.37%、76.81%、66.67%。Cd和Pb含量分别在0.5～2.0mg/L和0.2～0.4mg/L时酸模有较好的耐性。因此,酸模更适合于城市尾水中重金属的吸收修复,且对一定质量浓度Cd和Pb表现出较好的去除效果。

The Removal Effect of Heavy Metal from City Tail Water by Several Plants

In order to select suitable plant varieties for absorption of heavy metal from city tail water,the study focused on heavy metals of Zn,Cu,Pb and Cd removal efficiency from city tail water by sorrel(Rumex acetosa L.),herb of glomerate galingale(Cyperus glomeratus L.) and swamp morningglory(Ipomiea aquatica Forsk).The removal efficiency of Cd and Pb was also studied by sorrel from artificial wastewater.The results showed that the removal efficiency of Zn,Cu,Cd,Pb were 74.33%,60.43%,45.45% and 36.43%,respectively,by three plants in this experiment.Among the three plants,sorrel had the best removal effect on these heavy metals,followed by herb of glomerate galingale and swamp morningglory.The removal efficiency of Zn,Cu,Cd,Pb by sorrel were 86.63%,90.37%,76.81% and 66.67% respectively;when the contents of Cd and Pb were in the range of 0.5-2.0 mg/L and 0.2-0.4 mg/L,respectively,the removal efficiency of Cd,Pb were about 67% and 55% respectively by sorrel.However,high concentration of these heavy metals was toxic to sorrel,resulting in the biomass decrease.As a result,sorrel was more suitable for removing heavy metals from city tail water and had a great tolerance at the low concentration of Cd and Pb.