两性离子修饰的陶瓷膜抗污染性能评价毕业论文
2022-01-05 21:36:53
论文总字数:20522字
摘 要
自从工业革命以来,工业的发展对地球的生态环境和人类都产生了一定程度的不良的影响。其中大型的漏油事故严重的危害了水资源,废水排放不达标也正不断的侵蚀我们的环境。世界上水污染问题日趋严重,由此开发出了各类净水技术,其中,膜分离技术由于其无毒无害、操作简便、成本低的优点受到了关注。实验选用陶瓷膜作为分离材料,用两步法在陶瓷膜上接枝两性离子,对改性前后的陶瓷膜采用错流过滤的方式,通过考察不同体系下的渗透率和截留率,以评价两性离子修饰的陶瓷膜抗蛋白和油性物污染的性能。实验结果表明在无乳化剂油水乳液体系中,原膜和改性膜截留率基本不变,改性膜渗透率低于原膜,可能是两性离子降低了膜亲水性;在含乳化剂油水乳液体系中,改性膜渗透率和截留率均大于原膜,但几乎都是不可逆污染,可能是由于活性剂和油滴共同污染所致;在BSA体系中,改性膜的可逆污染大于原膜,不可逆污染小于原膜表明改性膜具有更好的抗蛋白吸附能力,表面吸附的蛋白质更易清洗,提高通量恢复率。
关键词:两性离子;陶瓷膜;抗污染
Evaluation of anti-pollution performance of zwitterionic modified ceramic membrane
Abstract
Since the industrial revolution, the development of industry has had a certain degree of adverse impact on the earth's ecological environment and human beings. Among them, the large-scale oil leakage accident has seriously harmed the water resources, and the waste water discharge is not up to the standard and is constantly eroding our environment. The problem of water pollution is becoming more and more serious in the world, so many kinds of water purification technologies have been developed. Among them, membrane separation technology has attracted attention because of its advantages of innocuity, simple operation and low cost. In the experiment, the ceramic membrane was selected as the separation material, and the amphoteric ion was grafted on the ceramic membrane by two-step method. The ceramic membrane before and after modification was filtered by cross flow filtration. The permeability flux and retention rate of the ceramic membrane under different systems were investigated to evaluate the anti protein and oil pollution performance of the amphoteric ion modified ceramic membrane. The experimental results showed that the rejection rate in the emulsifier free oil-water emulsion system was basically unchanged, and the rejection rate of the original membrane was greater than that of the modified membrane. It might be that zwitterionic reduced the membrane hydrophilicity. In the emulsifier containing oil-water emulsion system, the permeation flux and rejection rate of the modified membrane were greater than that of the original membrane, but almost all of them were irreversible pollution, probably due to the co pollution of the active agent and the oil droplet, and in the BSA system. Among them, the reversible pollution of the modified membrane is greater than that of the original membrane, and the irreversible pollution is less than that of the original membrane, which indicates that the modified membrane has better anti protein adsorption ability, the protein adsorbed on the surface is easier to clean, and the flux recovery rate is improved.
Key Words: Zwitterion; Ceramic membrane; Anti-fouling
目 录
摘 要 I
Abstract II
第一章 文献综述 1
1.1 引言 1
1.2 陶瓷膜发展 2
1.3 膜污染机制 2
1.4 膜亲水改性 3
1.4.1 物理法亲水改性 3
1.4.2 两性离子亲水改性 4
1.4.3 两性离子的抗污染特性 6
1.4.4 两性离子改性膜的应用 8
1.5本文研究思路 8
第二章 实验部分 10
2.1 实验仪器与材料 10
2.1.1 实验仪器 10
2.1.2 实验材料 10
2.1.3 实验装置 11
2.2 实验方法 12
2.2.1 陶瓷膜的改性 12
2.2.2 两性离子陶瓷膜的表征 12
第三章 结果与讨论 14
3.1 改性前后的陶瓷膜在牛血清白蛋白溶液中的应用 14
3.1.1 体系下渗透率及截留率的考察 14
3.1.2 改性前后的陶瓷膜在蛋白体系中抗污染性能的研究 15
3.2 改性前后的陶瓷膜在无乳化剂油水乳液中的应用 16
3.3 改性前后的陶瓷膜在含乳化剂油水乳液中的应用 17
3.3.1 体系下渗透率及截留率的考察 17
3.3.2 抗污染性能的研究 18
第四章 结论与展望 19
4.1 结论 19
4.2 展望 19
参考文献 20
致 谢 23
第一章 文献综述
1.1 引言
随着工业化和城市化的发展,石油开采、炼油、制药、食品、皮革纺织等工业生产和运输过程中往往会产生大量的含油废水,已经成为全球性的主要污染源之一,严重威胁到生态系统的稳定性。含油废水来源十分广泛,其成分也十分复杂,如汽油、柴油、煤油、动、植物油等不溶性油类化合物。含油废水对人类生活环境和生态平衡有很大的危害,如污染水资源,对生态环境造成严重污染和破坏、污染水质,危害人类的身体健康、聚结的油品燃烧产生安全隐患等。而在实际生产情况下往往乳液类型复杂,含乳化剂乳液,不含乳化剂乳液,水包油乳液,油包水乳液及它们的混合型,并且往往实际体系浓度更大,另一方面,在中药澄清、生物发酵液净化过程中也需要将其中的蛋白质,生物碱等杂质分离出来。而对于这样一些体系,膜分离体现出很好的分离效果并逐渐显示出其价值,成为具有前景的技术。膜分离是将膜作为分离介质,依靠着化学位差或外部能量作为推动力,对双组分或多组分的流体进行分离、浓缩与纯化的一种方法。对应的膜技术即是在通过半透膜时,对不同粒径的分子混合物实现选择性分离的技术[1]。半透膜也称滤膜或分离膜,膜壁上充满小孔。由孔径大小,可以划分为微滤膜(MF)、纳滤膜(NF)、超滤膜(UF)、反渗透膜(RO)等。由表层结构的差异,可以划分为多孔膜、致密膜、复合非对称修正膜等[2],其中多孔膜按照孔径尺寸大小可划分为:大孔膜(孔径大于50 nm)、介孔膜(孔径介于2~50 nm之间)、微孔膜(孔径小于2 nm)。常常采用错流过滤的方式进行膜分离过程,用料液来冲刷膜表面使污染物减少在膜表面的积累。膜分离过程是物理过程,因此具有低能耗、无相变、易控制等优点,对色素、胶体、大分子有机物等具有良好的分离性能。
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