發(fā)布時(shí)間：2018-03-29 19:51

  本文選題：滲透汽化　切入點(diǎn)：復(fù)合膜　出處：《北京化工大學(xué)》2017年碩士論文

【摘要】：因經(jīng)濟(jì)的飛速發(fā)展和環(huán)境污染的日益加重,我們可使用的水資源越來(lái)越少,這已經(jīng)是很多國(guó)家面對(duì)的重大挑戰(zhàn)。在我國(guó)北方水資源欠缺最嚴(yán)重的地區(qū),表面水和地下水基本被消耗殆盡。此外,因?yàn)樗廴締?wèn)題,水的質(zhì)量正在不斷惡化,從而加劇了現(xiàn)有的水資源的欠缺。傳統(tǒng)的分離技術(shù)由于其自身的特點(diǎn),在脫除無(wú)機(jī)物和有機(jī)物的領(lǐng)域過(guò)程中存在一定限制。探究新型的分離技術(shù)已經(jīng)成為現(xiàn)在研究的熱門。本文通過(guò)重新研究膜的材料和膜的結(jié)構(gòu),制備新型滲透汽化分離膜,從而達(dá)到提高分離性能的結(jié)果。本文綜述了研究與開發(fā)膜材料及膜結(jié)構(gòu)的過(guò)程,成功制備一系列具有高分離性能的滲透汽化復(fù)合膜。同時(shí),文中仔細(xì)分析了膜的材料和膜的結(jié)構(gòu)對(duì)滲透汽化分離技術(shù)的影響及兩者之間的關(guān)系,并深入研究了滲透汽化分離技術(shù)的理論及滲透汽化模型。主要工作如下:1、采用簡(jiǎn)單涂覆法成功獲得了(PDMS-Ti02)/PVDF滲透汽化復(fù)合膜。結(jié)果表明,在PDMS的分離層中,甲醛有較高的擴(kuò)散能力。在50℃時(shí),對(duì)1000ppm的甲醛水溶液進(jìn)行滲透汽化處理,測(cè)得最高總通量可以是140. 3g·m-2·h-1 選擇性可以為13. 1。將制備好的復(fù)合膜在溫度為50℃條件下,連續(xù)進(jìn)行25小時(shí)操作,該復(fù)合膜具有穩(wěn)定的通量和選擇性,證明其在長(zhǎng)時(shí)間高溫條件操作下,具有良好的穩(wěn)定性能。2、采用涂覆法制備了 SPTA-PVA/PVDF滲透汽化復(fù)合熱交聯(lián)膜。在含有磺酸基團(tuán)的皮層中,水分子有很高的擴(kuò)散能力。在70℃時(shí),將35000ppm的NaCl水溶液進(jìn)行滲透汽化處理,可以得到的最高水通量為35. 7L·m-2·h-1,截留率性能能夠維持在99. 8%以上。將制備好的復(fù)合膜在溫度為70℃條件下,連續(xù)進(jìn)行25小時(shí)操作,該復(fù)合膜具有穩(wěn)定的通量和截留率,能夠證明其在長(zhǎng)時(shí)間高溫條件操作下,具有良好的穩(wěn)定性能。3、研究了滲透汽化復(fù)合膜的傳質(zhì)機(jī)理,兵發(fā)現(xiàn)滲透汽化過(guò)程中發(fā)生汽化的位置。SPTA-PVA/PVDF復(fù)合膜滲透汽化處理35000ppm的NaCl溶液后,經(jīng)過(guò)EDS測(cè)試表明Na元素和C1元素含量在SPTA-PVA和PVDF邊界處發(fā)生明顯變化,說(shuō)明Na元素和Cl元素不能汽化,且滲透汽化位置發(fā)生在SPTA-PVA和PVDF邊界處。4、對(duì)滲透汽化復(fù)合膜的阻力進(jìn)行計(jì)算,可知致密層的阻力隨著致密層厚度的減少而減小,支撐層的表面孔隙率越小,平均孔徑越大,支撐層的阻力越小,從而來(lái)提高復(fù)合膜的傳質(zhì)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，

本文編號(hào)：1682618