人工湿地植物对电镀废水的净化和修复效果研究

Study on Phytopurification and Phytoremediation of Electroplating Sewage by Wetland Plants

通过在垂直流—水平潜流人工湿地系统进行采样和分析,研究了垂直流湿地(一级湿地)中水葫芦、稗草和水平潜流湿地(二级湿地)中藨草、黄菖蒲、芦苇、千屈菜、美人蕉对金华市某电镀厂经预处理后排水中主要污染物Cr、Zn、Fe、Mn、Ni和Cu的处理能力。结果表明,60 d后二级湿地中千屈菜、藨草、美人蕉长势最好,黄菖蒲正常生长,芦苇几乎停止生长,而一级湿地中水葫芦、稗草生长较缓慢。植物对电镀废水的净化和修复,因植物种类、部位、生物量、重金属种类等而不同。一级湿地中水葫芦对电镀废水的净化和修复效果强于稗草,二级湿地中藨草、美人蕉对电镀废水的净化和修复效果最好,其中藨草对Zn、Mn、Ni的转运系数和富集系数均大于1,美人蕉对Cr、Zn、Ni、Cu的转运系数大于1,对Zn、Mn的富集系数大于1。通过分析,二级湿地植物优势明显,其中藨草、美人蕉、黄菖蒲、千屈菜是值得推荐的修复中低浓度电镀废水优势种,在人工湿地系统污染物负荷较高的一级湿地应尽可能选用多种抗逆性强的湿地植物品种组合栽植。

A study was conducted on phytopurification and phytoremediation of electroplating heavy metals like Cr,Zn,F,Mn,Ni and Cu by wetland plants in Jinhua,Zhejiang province.The results showed that Lythrum salicaria,Scirpus triqueter,Canna indica grew well and Iris pseudocorus grew normally in the second class wetland,but Phragmites australis nearly stopped growth after 60 days.Eichhornia crassipes,Echinochloa crusgalli grew slowly in the first class wetland after 60 days.The effects of phytopurification and phytoremediation differed distinctively with plant species,organs,biomass and kinds of metals.S.triqueter and C.indica had higher capabilities of phytopurification and phytoremediation of electroplating sewage.Ei.crassipes had better removal ability than E.crusgalli.The S/R value and BCF of Zn,Mn,Ni of S.triqueter were both higher than 1.The S/R value of Cr,Zn,Ni,Cu of C.indica was higher than 1 and its BCF of Zn,Mn was also higher than 1.The study showed that the second class wetland was better suited for the plants,among which S.triqueter,I.pseudoacorus,L.salicaria and C.indica were recommended for purifying and remedying electroplating sewages of low-medium concentration.Plants with stronger resistance should be mixed planted in the first class wetland which had higher pollution load.