碳纳米管掺杂膜去除水中六价铬.doc

PAGE PAGE 20 碳纳米管掺杂膜去除水中六价铬 摘要：含铬废水排入环境中，会严重威胁人类健康和生态环境。因此，寻找高效的去除办法是刻不容缓的。吸附法具有高效、廉价、方便等特点，被认为是去除水中重金属最有应用前景的方法，而膜滤技术作为水处理新技术之一, 具有广阔的前景。 本论文将吸附法与过滤技术结合起来，使用碳纳米管掺杂膜、聚偏氟乙烯，制备聚偏氟乙烯—碳纳米管掺杂膜，去除水中六价铬，从碳纳米管含量、pH值、膜的投加量、Cr(Ⅵ)溶液浓度等方面，探究碳纳米管掺杂膜的最佳吸附效果条件。然后进行过滤实验，探究碳纳米管掺杂膜的去除效率。 通过吸附动力学实验可以了解到随着时间的增加，四种膜的吸附量不断增加，约16h后趋于平稳，含碳量越大的膜的吸附效果越好。对比不调pH与强酸性条件下，在强酸性条件下，碳纳米管掺杂膜的吸附效果更好。 pH=1.72条件下的等温吸附实验中，Cr(Ⅵ)溶液的浓度在0~20mg/L的范围内时，四种膜的吸附量基本上随浓度的增大而增大，且吸附量CNTs-15CNTs-10CNTs-5PVDF。 在探究pH对膜吸附Cr(Ⅵ)吸附效果影响的实验中，可以排除pH变化时，Cr(Ⅵ)溶液本身的吸光度变化。在酸性范围内四种膜的吸附效果比在中性以及碱性条件下好 过滤实验表明随着碳纳米管掺杂膜的含碳量的增加，水通量逐渐减小。且随着时间的增长，各种膜对Cr(Ⅵ)的截留过滤作用越来越小。掺杂膜的含碳量越高，过滤效果就越好。 关键词：碳纳米管；PVDF；吸附；过滤；六价铬 Removal of Hexavalent Chromium from Water by Carbon Nanotubes Hybrid Membrane Abstract: The wastewater containing chromium flows into the environment, create a serious threat to human health and ecological environment. Therefore, looking for efficient removal method is imperative. Moreover, Adsorption method has the characteristics of high efficiency, cheap and convenient, is considered to be one of the most prospect methods to removal heavy metals in water. And as one of the new technology of water treatment, membrane filtration technology has a broad prospect. Thus, Combining these two methods, forming PVDF-CNTs with Adsorption method and membrane filtration technology to remove hexavalent chromium, from the aspect of the carbon nanotubes content, pH value, the additive amount of membrane and concentration of Cr (Ⅵ) solution, etc. to explore the best adsorption of CNTs membranes’ effect. Then through filtering experiments, to explore the removal efficiency of CNTs membranes. Through the adsorption kinetics experiment ,we can know that with the increase of time, the four kinds of membrane adsorption quantity increase unceasingly, level off after about 16 h. Additionally, the larger the carbon content of membranes, the better the adsorption effect. Contrast not adjust pH and strongly acidic conditions, we can find that under the c