【作者】 李丹蓉；

【导师】 潘文斌；

【作者基本信息】 福州大学 ， 环境工程， 2006， 硕士

【摘要】 水体污染已经成为导致全球水资源短缺的一个重要因素。在对污染水体修复的各种手段中,植物修复是一种低成本,低能耗,易管理,利于资源化,利于整体生态环境改善的新技术,已经引起国内外学术界的高度重视。本文以花叶美人蕉、野芋、风车草和紫叶美人蕉作为受试植物,通过测定水体中污染物浓度的变化来研究受试植物对学生宿舍楼生活污水的净化效果。实验在室外自然条件下分为两个阶段进行。第一阶段采用生态浮床技术,研究污水不流动的静态条件下植物的生长状况以及植物对实验污水的适应性和去污能力。第二阶段采用生态浮床和人工湿地相结合的多级植物净化系统,研究污水在连续进水的动态条件下,污染物在各个植物净化槽中的浓度变化和去除率。本论文研究得出以下结论: 1.静态实验表明,受试植物在实验污水中均能正常生长,而且对实验污水具有良好的净化作用; 其中花叶美人蕉和风车草对COD_cr和BOD₅的去除效果要优于野芋; 但对NH₃–N、TN、TP、SS的去除效果,花叶美人蕉与野芋优于风车草。实验还表明,污水中污染物浓度随着停留时间的延长而降低。植物对污染物的去除效果与植物生长的状态有关。此外,上述这几种污染物的降解规律符合指数方程:Yt =Y₀*e^-kt,t是水力停留时间。2.动态实验采用连续进水的方式。废水依次流经缓冲槽—美人蕉槽—野芋槽—风车草槽—湿地槽等净化装置（本论文中美人蕉槽指的是花叶美人蕉槽,种植花叶美人蕉; 湿地槽种植有花叶美人蕉和紫叶美人蕉）。根据进水浓度不同,实验分三个阶段进行:（1）进水浓度COD_cr为63～81mg/L,NH₃–N为15～24 mg/L,TN为17～24 mg/L,TP为1.4～2.2mg/L时,CODcr、NH₃–N、TN、TP在该系统中的去除率分别约为85%,95%,94%,100%; 在美人蕉槽的去除率分别约为70%,57%,50%,78%; 在由美人蕉槽和野芋—风车草槽组成的浮床植物净化系统的去除率分别约为78%,93%,68%,97%。（2）当进水COD_cr为136～176 mg/L,NH₃–N为27～32mg/L,TN为28～33 mg/L时,TP为1.8～2.2mg/L时,CODcr、NH₃–N、TN、TP在该系统中的去除率分别约为94%,99%,85%,100%; 在美人蕉槽分别约为55%,50%,45%,72%; 在浮床植物净化系统分别约为82%,94%,72%,97%。（3）当进水浓度COD_cr 为245～300 mg/L,NH₃–N为40～50mg/L,TN为42～53 mg/L,TP为2.8～3.3mg/L时,COD_cr、NH3–N、TN、TP在该系统中的去除率分别约为95%,93%,89%,100%; 在美人蕉槽分别为61%,45%,23%,75%; 在浮床植物净化系统分别为84%,74%,67%,97%。更多还原

【Abstract】 Water pollution is a main factor causing shortage of water supply. As a new, cheap and ecological sound technology, phytoremediation of polluted water attracts many scientists all over the world. In this paper, Canna generalis Bailey, Colocasia esculenta L., Cyperus alternifolius L. and Canna warscewiezii A. Dietr were used to study the function of getting rid of pollutants in the water body. All the experiments were carried out in outdoor natural condition. The study included two stages. The first stage was using ecological floating bed technology, and the second was using combined system that included ecological floating bed technology and a small constructed wetland. The results were summarized as follows: 1. Under outdoor natural condition, Canna generalis Bailey, Colocasia antiquorum Schott and Cyperus alternifolius L. grew up well in wastewater. The static experiment investigated these three kinds of plant had good abilities to get rid of pollutants in wastewater; Canna and Cyperus had priority to get rid of chemical oxygen demand （COD） and biological oxygen demand （BOD）, while Canna and Colocasia had priority to get rid of ammonium （NH3–N）, total nitrogen （TN）, total phosphorus （TP） and suspended solids （SS）. With hydraulic retention time increasing, the pollutants concentrations were decreasing. The experiment also investigated decontamination ability was related to how the plants grow up. Result of statistics analysis showed that the rule of decontamination followed exponential function Yt =Y₀*e^-kt, where t denoted hydraulic retention time（HRT）. 2. Dynamic experiment was operated under a condition of continuous water input. The tanks wastewater flowed through were listed as follows, buffer tank, Canna-tank, Colocasia-tank, Cyperus-tank and a small constructed wetland. Dynamic experiments included three stages according with different influent: （1）When the influent with COD_cr 63～81mg/L, NH₃–N15～24 mg/L, TN 17～24 mg/L, TP 1.4～2.2mg/L, in this combined system, the removal rate of CODcr, NH₃–N, TN and TP was 85%, 95%, 94% and 100% respectively. And in the Canna-tank, it was 70%, 57%, 50%, and 78% respectively; in the whole floating bed system, it was 78%, 93%, 68% and TP97% respectively. （2）When the influent with COD_cr 136～176 mg/L, NH₃–N27～32mg/L, TN 28～33 mg/L, TP 1.8～2.2mg/L, in this combined system, the removal rate of COD_cr, NH3–N, TN and TP was 94%, 99%, 85% and 100% respectively. In the Canna-tank, it was 55%, 50%, 45% and 72% respectively. In the floating bed system, it was 82%, 94%, 72% and 97% respectively. （3）When the influent with CODcr245～300mg/L, NH3–N40～50mg/L, TN 42～53 mg/L,TP 2.8～3.3mg/L, in this combined system, the removal rate of CODcr, NH3–N, TN and TP was 95%, 93%, 89% and 100% respectively. And in the Canna-tank, it was 61%, 45%, 23% and 75% respectively. In the floating bed system, it was 84%, 74%, 67% and 97% respectively. All above, this combined system utilized a series of tanks to treat wastewater with the cooperation between vegetation and a variety of other organisms. This technology had good abilities to get rid of CODcr, BOD5, SS, NH3–N, TN and TP in wastewater. The research has not only explored the phytoremediation theory and technology of sewage treatment, but also gived us a new way of thinking and technical support of ecological sewage treatment. The technology would be positive for water pollution control and the water quality improvement of small towns in the future.更多还原