人工湿地植物处理含重金属生活废水的实验研究  

Characteristics of Selected Wetland Plant Species for Removal of Zn^(2+)/Cd^(2+) from Wastewater

作　　者：陈明利[1] 张艳丽[1] 吴晓芙[1] 纪智慧[1] 

机构地区：[1]中南林业科技大学资源与环境学院,湖南长沙410004

出　　处：《环境科学与技术》2008年第12期164-168,共5页Environmental Science & Technology

基　　金：国家林业局948项目"水环境保护中的湿地技术"(2005-4-31);湖南省教育厅产业化推广项目"污水系列深度处理技术配套与推广"(2003-101)

摘　　要：通过耐受浓度试验得出凤眼莲、水蕹、水花生和荇菜四种植物对含重金属生活污水中Cd2+的耐受范围值分别<5mg/L、0.5mg/L、0.2mg/L、0.2mg/L;凤眼莲和水花生对Zn2+的耐受范围值分别<10mg/L,水蕹和荇菜对Zn2+耐受范围值为<5mg/L和0.5mg/L。由植物对生活污水中锌\镉离子去除率试验可知,在Cd2+/Zn2+浓度分别为0.5mg/L和5mg/L时,与对照组相比,两种植物均能明显去除污水中的Zn2+与Cd2+,其中Cd2+去除率提高了65.3%,Zn2+去除率提高了43.7%。研究发现植物处理在前5d内为去除Zn2+/Cd2+的高效区间,这一时期内植物对Zn2+/Cd2+去除率的贡献可以达到40%～60%,表明在植物的耐受浓度范围内,湿地植物对生活污水中的Cd2+/Zn2+有较好的去除效果,根部为主要的富集器官。Experiments were carded out to test the ability of four selected plant species introduced into a constructed wetland system for removal of Zn^2＋ and Cd^2＋ from municipal wastewater mixed with lab wastewater. The highest concentration limit of Cd^2＋ that the selected species could endure was found to be 5, 0.5, 0.2 and 0.2mg/L respectively, for Eichhornia crassipes, Ipomoea aquatica, Alternanthera philoxeroide and Nymphoides peltatum, while that of Zn^2＋ was 10mg/L for Eichhornia crassipes and Alternanthera philoxeroide, 5mg/L for lpomoea aquatica and 0.5mg/L for Nymphoides peltatum. In the treatment experiments the two hydrophytes, Eichhornia crassipes and lpomoea aquatica, removed significant amount of Zn^2＋ and Cd^2＋ from the tested wastewater at concentration Zn^2＋ and Cd^2＋ of 0.5mg/L and 5mg/L. Compared to that in the control of the removal rate of Zn^2＋ and Cd^2＋ in plant treatment cells was enhanced by 45.7% and 65.3% respectively. A high treatment efficiency phase was observed in the first five days, within which the removal rate of Zn^2＋ and Cd^2＋ reached 40% and 60% respectively. Presence of such a high removal rate could be attributed to a root adsorption effect in the initial treatment period.

关 键 词：人工湿地 植物 锌 镉 去除率 生活污水 

分 类 号：X703[环境科学与工程—环境工程]