正渗透膜分离技术处理校园生活污水的试验研究

发布时间：2018-05-24 22:24

本文选题：正渗透膜分离技术 + 海水　；参考：《青岛理工大学》2015年硕士论文

【摘要】：目前我国污水处理现状存在工艺脱氮除磷效果不够理想、工艺运行能耗大、污水处理成本高等问题。膜分离技术因其污水处理的高效性得到了广泛的研究和实际的应用,其中无需外加压力驱动的正渗透(FO)膜分离技术作为一种新发展起来的膜分离技术,因其能耗低、截留率高、膜污染可逆等优点在废水处理、食品医药加工、海水淡化、能源开发等方面不断得到重视,显现了潜在的研究及利用价值。为探究正渗透膜分离技术对实际校园生活污水的处理效果及膜污染问题,为正渗透膜分离技术处理校园生活污水的实际运行、调控及海水作为驱动液的可行性等方面提供实验依据,本论文以正渗透膜分离设备为试验装置,美国HTI公司的TFC-ES膜为正渗透膜材料,青岛团岛海域的天然海水作为驱动液进行了试验研究。首先,论文对TFC-ES正渗透膜性能进行了研究评价,原料液为蒸馏水,驱动液为海水。在通过SEM图像对该正渗透膜的形态结构进行表征的基础上,试验研究了正渗透过程中膜朝向、错流速度两个影响因素对膜的水通量和驱动溶质逆向渗透现象的影响。结果表明：采用FO模式(即活性层朝向原料液,支撑层朝向驱动液)时膜的初始水通量比采用PRO模式(即活性层朝向驱驱动液,支撑层朝向原料液)时的小,整体水通量变化趋势也较小,驱动溶质逆向渗透到原料液中的量也较小；当将错流速度由1L/min提高到1.5L/min再提高到2L/min时,在其他运行条件一致的情况下,水通量随着错流速度的增大而增大,驱动溶质的逆向渗透现象也更严重。其次,试验将TFC-ES膜用于正渗透膜分离系统,对系统处理实际校园生活污水的效果进行了研究,原料液为校园生活污水,驱动液为海水。结果表明：FO模式下膜的水通量比PRO模式下的小,水通量的下降趋势也较小,水通量较稳定,且对污水中的氨氮、亚硝酸盐氮、硝酸盐氮的截留效果也比PRO模式下的好；当采用FO模式且保持其他运行条件不变,将膜两侧的错流速度从1L/min提高到1.5L/min再提高到2L/min时,随着错流速度的增加,水通量随之增加,但污水中的氨氮、亚硝酸盐氮、硝酸盐氮透过正渗透膜的量也会增加,对污染物质的截留率降低。最后,试验对正渗透膜分离过程中的膜污染及膜清洗情况进行了探究,对FO模式、PRO模式两种模式下处理相同时间生活污水的TFC-ES膜采用去离子水浸泡+设备运行冲洗的物理方法进行清洗,并对两种模式下的污染的膜和清洗的膜进行水通量测试,可知FO模式下污染的膜的水通量比PRO模式下的下降幅度低,表明系统在FO模式下运行膜污染程度较低；FO模式下污染的膜清洗后的膜清洗效率达到98.8%,而PRO模式下污染的膜经过清洗后清洗效率达到96.5%,水通量都基本恢复到污染前的值,这表明采用简单的物理清洗可以使正渗透膜的性能基本恢复,且系统在FO模式下运行的膜污染较轻,清洗效果更明显。另外,通过扫描电镜的结果可知：正渗透膜分离过程中的膜污染较轻,污染物只是简单松散的附着在膜表面,通过简单的物理方法清洗后,基本可以恢复膜表面的初始形态。
[Abstract]:At present, the current situation of wastewater treatment in China is not ideal for nitrogen and phosphorus removal, high energy consumption and high cost of sewage treatment. Membrane separation technology has been widely studied and applied because of the efficiency of sewage treatment. No pressure driven positive permeation (FO) membrane separation technology is used as a new development. Because of its low energy consumption, high interception rate and reversible membrane fouling, the membrane separation technology has been paid more attention to wastewater treatment, food processing, desalination, energy development and so on, showing potential research and utilization value. In this paper, the positive osmosis membrane separation technology is used to deal with the actual operation of campus sewage, control and the feasibility of sea water as a driving fluid. This paper takes the positive permeable membrane separation equipment as the test device, the TFC-ES membrane of HTI company in the United States as the positive permeable membrane material, and the natural seawater in the Qingdao island sea area as the driving fluid. First, the performance of the TFC-ES positive permeable membrane was studied and evaluated. The liquid was distilled water and the driving liquid was sea water. On the basis of the characterization of the morphological structure of the positive permeable membrane through the SEM image, the water flux and the inverse of the solute driven by the two factors affecting the membrane orientation and the velocity of the flow in the positive permeation process were studied. The results show that the initial water flux of the membrane is smaller than that of the PRO mode when the FO mode (the active layer toward the raw material and the supporting layer toward the driving fluid) is smaller than that by the use of the active layer toward the drive fluid and the support layer toward the raw material. It is also smaller. When the flow rate is increased from 1L/min to 1.5L/min and then to 2L/min, the water flux increases with the increase of the flow rate, and the reverse osmosis of the solute is more serious when the other operating conditions are consistent. Secondly, the TFC-ES film is used in the positive permeable membrane separation system to deal with the actual campus life in the system. The effect of sewage is studied. The liquid is the campus sewage and the driving liquid is sea water. The result shows that the water flux in the FO model is smaller than that under the PRO model, the downward trend of water flux is smaller, the water flux is more stable, and the effect of the ammonia nitrogen, nitrite nitrogen and nitramine nitrogen in the sewage is better than that in the PRO model. With FO mode and other operating conditions unchanged, the water flux increases with the increase of the flow rate from 1L/min to 1.5L/min and then to 2L/min, but the amount of ammonia nitrogen, nitrite nitrogen, nitrate nitrogen through the positive permeation membrane in the sewage will also increase, and the interception rate of the contaminated material will be reduced. Finally, The membrane fouling and membrane cleaning in the separation process of the positive permeable membrane were investigated. The physical methods of deionized water immersion + equipment running and washing in the two modes of FO mode and PRO mode for treating the same time sewage in the two modes were carried out, and the water flux of the contaminated membrane and the cleaning film under the two modes was carried out. The test shows that the water flux of the polluted membrane under the model of FO is lower than that under the PRO model, indicating that the membrane fouling of the system under the FO mode is low; the membrane cleaning efficiency after the cleaning of the membrane under the FO mode is 98.8%, while the cleaning efficiency of the polluted membrane under the PRO mode is 96.5%, and the water flux is basically recovered to the pollution. It shows that the performance of the positive osmosis membrane can be basically recovered by simple physical cleaning, and the membrane pollution of the system under FO mode is lighter and the cleaning effect is more obvious. In addition, the results of the scanning electron microscope show that the membrane fouling in the separation process of the positive osmosis membrane is lighter, and the pollutants are simply and loosely attached to the membrane surface. After cleaning by a simple physical method, the initial shape of the film surface can be basically restored.
【学位授予单位】：青岛理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X799.3

【参考文献】