水芹和菖蒲对Pb-Cd污染水体的净化与修复试验研究

【作者】 邱树敏；

【导师】 叶雪均；

【作者基本信息】 江西理工大学 ， 环境工程， 2010， 硕士

【摘要】 目前,水体重金属污染日益受到人们的共同关注,这也成为研究国内外水环境污染治理的难题和焦点。对于我国这样一个矿业资源丰富的大国,在矿区进行水体重金属修复是一项新的课题。本文针对广西车河选矿厂灰岭尾矿库废水的情况,以筛选适合的净化水体重金属污染的水生植物为试验研究,通过对该地的调查和比较前人的实验,选取水芹和菖蒲作为本次的研究对象。从单一的重金属Pb²⁺、Cd²⁺与水生植物关系,研究了不同的离子浓度下水生植物的生长状况、水生植物对Pb²⁺、Cd²⁺的吸收去除、不同时间下对Pb²⁺、Cd²⁺净化效果、水生植物体内重金属Pb²⁺、Cd²⁺的积累量以及水生植物生理的状况。实验结果表明,不论水芹或菖蒲,均生长良好,其中菖蒲的去除效果明显于水芹,菖蒲对Pb²⁺、Cd²⁺的去除率达到90.4%和87.5%,水芹对Pb²⁺、Cd²⁺的去除率达到74.7%和73.3%。通过水培实验,研究复合重金属离子对水生植物的生长、积累量以及Pb-Cd交互作用,实验结果表明:对于水芹和菖蒲,Pb-Cd相互作用效应与多种因素有关,包括重金属之间浓度组合、植物种类和植株部位等,表现得极为复杂,不仅仅是单纯的加和、拮抗或协同作用。本文通过用离子内扩散方程,Lagergren准一级动力学方程和准二级动力学方程对水芹和菖蒲对重金属的吸附机理进行了研究分析,结果表明:用离子内扩散方程验证发现,水芹和菖蒲对Pb²⁺、Cd²⁺的吸附过程是一个多线性吸附过程;吸附在整个过程不完全符合Lagergren准一级动力学模式,只是部分符合。准二级动力学方程进行各种拟合发现,其误差均小于离子内扩散方程和Lagergren准一级动力学的误差。通过误差分析,把分析结果按从大到小的顺序排列:离子内扩散方程＞准一级动力学模式＞准二级动力学模式。由此可以证实水芹和菖蒲对Pb²⁺、Cd²⁺的吸附过程的吸附过程符合准二级动力学方程。更多还原

【Abstract】 At present, the heavy metal pollution causes the attention by us gradually. This also becomes the difficult problem and focus in studying water environment pollution at home and abroad. As a country being abundant in coal natural resources, it is a new subject by carrying out phytoremediation technology in heavy metal mining areas.In this paper, the heavy metal pollution is investigated and assessed in the heavy mining areas of GuangXi province. Plants growth and heavy metal accumulation of accumulating ecotypes of the selected planted were studied by hydroponics experiments. On the basis of preliminary experiment, the effects of oenanthe javaniaca BI. and Acorus calamusL. on single Pb or Cd, and Pb-Cd compound pollution were studied.Firstly, to elucidate the characteristics of single Pb or Cd in aquatic plants, a series of chemical, biochemical analytic techniques were used to study the growth, the absorption, the removing efficiency of Pb or Cd, the accumulation and physiological response of the plants. The results show that: both oenanthe javaniaca BI. and Acorus calamusL. could grow well in the solution culture experiment, and the purifying efficiency of Acorus calamusL. was superior to oenanthe javaniaca BI.. The removal rates of Pb, Cd by Acorus calamusL. were 90.4%, 87.5% respectively; and that of Pb, Cd by oenanthe javaniaca BI. were 74.7%, 73.3%.Secondly, using the method of aquatic culture, the growing responses, the accumulating charactertics of oenanthe javaniaca BI. and Acorus calamusL. with high tolerance to Pb-Cd compound pollution and the relationship between Pb and Cd reported in the previous study were further investigated. For the two aquatic plants, the interactive effect of Pb and Cd was complicated, not simply additive, antagonist and synergistic, but also related with many factors, including various concentration combinations of heavy metals, plant species and different tissues.Thirdly, the study investigates the mechanism of heavy metal ions(Pb²⁺, Cd²⁺) adsorption of oenanthe javaniaca BI. and Acorus calamusL. was analyzed by the intraparticle diffusion modle, the pseudo-first-order and the pseudo-second-order equations. The results indicate as follow: adsorptions of Pb²⁺, Cd²⁺ onto oenanthe javaniaca BI. and Acorus calamusL. are multi-linear processes including three processes; the calculated Qe values obtained from linear regression of the Lagergren equation is far deviated from the experiment data. In addition, it was observed that the sorption data were well represented by the lagegren modle only for the first process; and comparison of error analysis of the intraparticle model, the pseudo-first-order and pseudo-second-order equations, the result show that the order of deviation was intraparticle diffusion model> the pseudo-first-order >pseudo-second-order. It was confirmed that the pseudo-second-order was the best one in describing the adsorption kinetics of Pb²⁺,Cd²⁺ onto oenanthe javaniaca BI. and Acorus calamusL..更多还原