超滤-电渗析耦合有机水体脱盐的研究

发布时间：2018-02-24 12:27

本文关键词： 电渗析超滤有机物脱盐膜污染　出处：《天津工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：随化工、制药、造纸等行业的发展,排放了大量的含低熔点碱金属盐和碱土金属盐的高浓度有机废液,这些废液往往毒性较高,如果直接排放将造成严重的环境污染,在处理过程中又往往因为废水中含有较高的盐分含量,限制其后续的处理过程。常规的生化处理方法等又无法解决此类污染问题。因此,开发一种更为可靠、更为有效的含盐高浓度有机废液处理方法己是废液污染治理的迫切需求。本文结合电渗析和超滤的优点,找到了一种新型的超滤-电渗析耦合的方式处理含盐高浓度有机废液的方法,有效分离的有机物和无机盐离子,为含盐高浓度有机废液的连续稳定无害化处理提供了一种可靠、可行的方法,具有重要的应用价值。超滤-电渗析是在传统的电渗析器中引入超滤膜,或是用超滤膜取代部分离子交换膜的一种新型膜分离技术。本文应用超滤-电渗析分离高盐有机料液中的有机物和无机离子。首先,比较了不同的超滤-电渗析耦合方式,选出适合进行有机水体脱盐的膜堆构型,即超滤膜替换电渗析装置中的阴离子交换膜。并且探究循环模式进行脱盐实验时,不同操作参数对脱盐效果的影响。结果发现,电压为6.5V时更有利于脱盐,电压过大会造成膜污染;料液流速为1Ocm/min时,停留时间长,脱盐效果好,.浓水与料液流速相同时,确保了两隔室之间没有压差,减轻有机物对膜的污染。其后,研究膜堆结构中不同材料膜对脱盐过程的影响,从而可知,超滤膜和离子交换膜相比较,超滤膜更不容易被蛋白质污染,并且当超滤膜截留分子量远大于有机分子相对分子质量时,有机分子不会透过超滤膜,其在超滤膜表面有少许附着对脱盐过程影响不大,但是如果电压过大或者有垂直于膜的压力时超滤膜会被污染进而影响脱盐效果。最后,为了实现水体连续脱盐,设计了三级连续电渗析。除盐率达到98.6%,进行8h连续运行,出水水质比较稳定。结合对超滤膜污染的研究,得出结论,在该过程中超滤膜的污染轻微,未对脱盐效果造成影响。在本项研究中,设计了超滤-电渗析除盐方法,研究了操作条件对分离效果的影响,并取得了有机物与无机离子分离的良好效果,为有机水体脱盐技术的开发提供了新的思路和技术支持。
[Abstract]:With the development of chemical, pharmaceutical, papermaking and other industries, a large amount of high concentration organic waste liquid containing low melting point alkali metal salt and alkali earth metal salt has been discharged, which is often highly toxic and will cause serious environmental pollution if discharged directly. In the process of treatment, it is often because of the high salt content in the wastewater, which limits its subsequent treatment process, and the conventional biochemical treatment methods can not solve the problem of such pollution. Therefore, the development of a more reliable, More effective treatment of organic waste liquor with high concentration of salt has been an urgent need for the treatment of waste liquor pollution. This paper combines the advantages of electrodialysis and ultrafiltration. A new coupling method of ultrafiltration and electrodialysis has been found for the treatment of organic waste liquor with high concentration of salt. The effective separation of organic matter and inorganic salt ions provides a reliable method for the continuous and harmless treatment of organic waste liquor with high concentration of salt. The feasible method has important application value. Ultrafiltration and electrodialysis are introduced into the traditional electrodialysis device. In this paper, ultrafiltration and electrodialysis are used to separate organic and inorganic ions from high salt organic liquid. Firstly, different coupling methods of ultrafiltration and electrodialysis are compared. The membrane stack configuration suitable for desalting of organic water was selected, that is, the ultrafiltration membrane was used to replace the anion exchange membrane in the electrodialysis unit, and the effect of different operating parameters on the desalination efficiency was investigated in the experiment of desalting in circulating mode. When the voltage is 6.5 V, it is more favorable to desalination, and the overvoltage will cause membrane fouling. When the flow rate of feed liquid is 1 m / min, the residence time is long and the desalination effect is good. When the flow rate of concentrated water and feed liquid is the same, no pressure difference between the two compartments is ensured. The effect of different materials on the desalination process was studied. It was concluded that the ultrafiltration membrane was less likely to be contaminated by protein than the ion exchange membrane. When the molecular weight of UF membrane is much larger than the molecular weight of organic molecule, the organic molecule will not pass through UF membrane, and a little adhesion on the surface of UF membrane has little effect on the desalination process. But if the voltage is too high or the pressure is perpendicular to the membrane, the ultrafiltration membrane will be polluted and the desalination effect will be affected. Finally, in order to realize the continuous desalination of water, a three-stage continuous electrodialysis is designed. The effluent quality is relatively stable. In combination with the study of ultrafiltration membrane pollution, it is concluded that the ultrafiltration membrane contamination is slight and does not affect the desalination effect. In this study, the ultrafiltration and electrodialysis desalination method is designed. The effect of operating conditions on the separation effect was studied, and a good result of separating organic compounds from inorganic ions was obtained, which provided a new idea and technical support for the development of desalting technology in organic water.
【学位授予单位】：天津工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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