【作者】 窦明岳；

【导师】 杨建华；

【作者基本信息】 大连理工大学 ， 化学工程与技术， 2011， 硕士

【摘要】 膜分离技术具有操作方便、节能、无相变、易实现规模化等优点,但是微滤、超滤膜在处理含油废水推广中依然存在着诸多的问题,如膜污染和浓差极化等引起的分离性能下降制约着无机膜大规模工业化应用。因此,为了克服上述问题,高亲水疏油性的膜材料的开发研制有着十分重要的理论和实际意义。本文利用硅溶胶浸渍提拉法对大孔α-Al2O3微滤膜进行修饰改性；通过在流动体系中用NaA沸石修饰大孔α-Al2O3微滤膜,制备出具有不同孔径的NaA改性微滤膜；分别将上述修饰改性的微滤膜应用到含油废水的处理。利用SEM、N2渗透测试、纯水通量测定和孔径分布分析等表征手段考察微滤膜形态结构和亲水性能,主要内容如下：(1)通过正交试验设计法,考察了硅溶胶浓度、浸渍时间和浸渍次数对SiO2改性微滤膜性能的影响。结果表明,合适改性条件为,硅溶胶浓度为5%,浸渍时间是30s,浸渍-焙烧不同的次数,可以制备出不同孔径的Si02改性微滤膜。(2)经Si02改性过的微滤膜亲水性能得到明显提高。孔径为1.65μm的Si02改性微滤膜处理含油废水的截留率为96%,而0.74μm和0.48μm的Si02改性微滤膜处理含油废水的截留率均可达99%以上；三者通量分别为110L/m-2h、47L/m-2h和32L/m-2h。(3)考察了改性条件对流动体系中在α-Al2O3微滤膜上进行NaA改性的影响。对于配方为56Na2O:1A12O3:5SiO2:xH2O的合成液体系,合适的NaA改性微滤膜的制备条件为：H2O:SiO2为500,流速为1mm/s,调节合成时间可制备出不同孔径的NaA改性微滤膜。(4)经NaA沸石修饰过的α-Al2O3微滤膜,其亲水性有明显提高,随着合成时间的延长,α-Al2O3微滤膜被NaA沸石覆盖率增加。NaA改性微滤膜在处理含油废水的过程中表现出很高的亲水疏油性,孔径为0.96μm和0.2μm的NaA改性微滤膜的截留率分别为98.6%和99.1%,且通量分别达到84L/m-2h和47L/m-2h。更多还原

【Abstract】 Membrane technology has many advantages, such as convenient operation, low-energy requirements, no phase transformation, simple to device the scale, however, for microfiltration and ultrafiltration membranes in dealing oil wastewater there still are still many problems, such as membrane pollution and strong polarization which may cause separation performance degradation, limiting the inorganic membrane intensive industrial applications. Therefore, in order to overcome the above problems, the research of high water hydrophilic inorganic membrane materials has a very important theoretical and practical significance.In this article using silicon sol and dip-coating technique SiO2 modified microfiltration membranes were also prepared on the above supports;α-Al2O3 membrane was also modified by deposition of NaA zeolite under flowing synthesis condition and the NaA modified microfiltration membranes with different pore diameter were prepared; the as-prepared ultrafiltration membranes were applied to the treatment of wastewater with oil, respectively. Moreover, morphology and structure of these membranes were characterized by SEM, N2 permeation test, water flux and pore size distribution analysis. And some novel findings in this work are as follows:(1) By the orthogonal design method, some parameters such as the concentration of silicon sol and, dip-coating time and impregnation times for the preparation of SiO2 modified microfiltration membrane were investigated. It’s found that the as-prepared membrane has well morphology and structure at the concentration of silicon sol of 5% and dip-coating time of 30 s.(2) The SiO2 modified microfiltration membrane shows favorable hydrophilic performance compared with the original support. In the treatment of oil wastewater, the interception rates for SiO2 modified microfiltration membranes with pore diameters of 1.65μm,0.74μm and 0.48μm were 95% ,>99% and>99%. And the corresponding fluxes were up to 110 L/m-2h,47 L/m-2h and 32 L/m-2h.(3) The effects of operation conditions in the flow system on the membrane performance were investigated. For the synthesis solution of 56Na2O:1Al2O3:5SiO2:XH2O, when the was 500, the flow velocity was 1mm/s, the as-prepared membrane has good performance. By adjusting the synthesis time membranes with different pore diameters can be prepared.(4) The hydrophilic performance of zeolite modified Al2O3 support was enhanced significantly. With the extension of synthesis time, the coverage of NaA zeolite on the Al2O3 support was increased. In the treatment of oil wastewater the NaA modified support exhibited high performance, such as interception rates for membranes with 0.96 and 0.23μm were up to 98.6% and 99.1%, and the fluxes were up to 84L/m-2h and 47L/m-2h.更多还原