新型渗透汽化膜材料的制备及其水处理应用研究

发布时间：2018-03-29 19:51

  本文选题：渗透汽化　切入点：复合膜　出处：《北京化工大学》2017年硕士论文

【摘要】：因经济的飞速发展和环境污染的日益加重,我们可使用的水资源越来越少,这已经是很多国家面对的重大挑战。在我国北方水资源欠缺最严重的地区,表面水和地下水基本被消耗殆尽。此外,因为水污染问题,水的质量正在不断恶化,从而加剧了现有的水资源的欠缺。传统的分离技术由于其自身的特点,在脱除无机物和有机物的领域过程中存在一定限制。探究新型的分离技术已经成为现在研究的热门。本文通过重新研究膜的材料和膜的结构,制备新型渗透汽化分离膜,从而达到提高分离性能的结果。本文综述了研究与开发膜材料及膜结构的过程,成功制备一系列具有高分离性能的渗透汽化复合膜。同时,文中仔细分析了膜的材料和膜的结构对渗透汽化分离技术的影响及两者之间的关系,并深入研究了渗透汽化分离技术的理论及渗透汽化模型。主要工作如下:1、采用简单涂覆法成功获得了(PDMS-Ti02)/PVDF渗透汽化复合膜。结果表明,在PDMS的分离层中,甲醛有较高的扩散能力。在50℃时,对1000ppm的甲醛水溶液进行渗透汽化处理,测得最高总通量可以是140. 3g·m-2·h-1 选择性可以为13. 1。将制备好的复合膜在温度为50℃条件下,连续进行25小时操作,该复合膜具有稳定的通量和选择性,证明其在长时间高温条件操作下,具有良好的稳定性能。2、采用涂覆法制备了 SPTA-PVA/PVDF渗透汽化复合热交联膜。在含有磺酸基团的皮层中,水分子有很高的扩散能力。在70℃时,将35000ppm的NaCl水溶液进行渗透汽化处理,可以得到的最高水通量为35. 7L·m-2·h-1,截留率性能能够维持在99. 8%以上。将制备好的复合膜在温度为70℃条件下,连续进行25小时操作,该复合膜具有稳定的通量和截留率,能够证明其在长时间高温条件操作下,具有良好的稳定性能。3、研究了渗透汽化复合膜的传质机理,兵发现渗透汽化过程中发生汽化的位置。SPTA-PVA/PVDF复合膜渗透汽化处理35000ppm的NaCl溶液后,经过EDS测试表明Na元素和C1元素含量在SPTA-PVA和PVDF边界处发生明显变化,说明Na元素和Cl元素不能汽化,且渗透汽化位置发生在SPTA-PVA和PVDF边界处。4、对渗透汽化复合膜的阻力进行计算,可知致密层的阻力随着致密层厚度的减少而减小,支撑层的表面孔隙率越小,平均孔径越大,支撑层的阻力越小,从而来提高复合膜的传质效率。
[Abstract]:As a result of the rapid development of the economy and the increasing pollution of the environment, there are fewer and fewer water resources available to us, which is already a major challenge for many countries. In the northern part of our country, where water resources are most lacking, Surface water and groundwater are largely depleted. In addition, because of water pollution, the quality of water is deteriorating, thus exacerbating the shortage of existing water resources. Traditional separation techniques are due to their own characteristics, There are some limitations in the field of removal of inorganic matter and organic matter. It has become a hot topic to explore new separation technology. In this paper, a new pervaporation membrane was prepared by re-studying the membrane material and membrane structure. In this paper, the process of research and development of membrane materials and membrane structure is reviewed, and a series of pervaporation composite membranes with high separation performance are successfully prepared. In this paper, the influence of membrane material and membrane structure on pervaporation separation technology and the relationship between them are analyzed in detail. The theory of pervaporation separation technology and the pervaporation model are studied. The main work is as follows: 1. The PDMS-Ti02 / PVDF composite membrane was successfully obtained by simple coating method. The results show that in the separation layer of PDMS, Formaldehyde has high diffusivity. When pervaporation of formaldehyde solution of 1000ppm is carried out at 50 鈩，

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