超薄Al2O3平板陶瓷膜的成膜过程及其在含油废水处理的抗膜污染性研究

The ultra-thin flat ceramic membrane has the advantages of low permeability resistance and low treatment cost, and has a unique advantage in the treatment of oily wastewater and biological products. However, the problem of membrane defects and membrane fouling caused by ultra-thin support and submerged filtration is an unsolved problem in the large-scale industrialization application of the flat ceramic membrane. In this project, the negative pressure filtration is used to solve the problem of the thickness of the flat ceramic membrane and the nanometer oxide modification is adopted to improve the oil pollution resistance, thus the ultra-thin ceramic membrane without defects and pollution is obtained. The preparation of membrane on the ultra-thin flat support is studied to understand the key factors affecting the membrane thickness and to grasp the basic principle of the preparation of the defect-free ultra-thin flat ceramic membrane with controllable membrane thickness; The ultra-thin flat ceramic membrane is modified using nano metal oxide to reduce the action intensity between the membrane surface and the pollutants in treating oily wastewater. Further, the rule to improve the anti-fouling property of the ultra-thin flat ceramic membrane is mastered. Finally, the treatment conditions of oily wastewater by the ultra-thin flat ceramic membrane are further optimized. The research results of this project can not only enrich the theory of ceramic membrane separation technology, but also expand the application of ceramic membrane in the petroleum chemical industry, biological medicine, environmental protection and water treatment, which has good economic and social benefits.

超薄平板陶瓷膜具有渗透阻力小，处理费用低的优点，在处理含油废水或者生物制品方面具有独特的优势。但是，超薄的支撑体和浸没式过滤模式引起的膜缺陷和膜污染问题是实现平板陶瓷膜大规模工业化应用尚未解决的科学问题。本项目提出采用负压过滤解决平板陶瓷膜膜厚问题和采用纳米氧化物修饰提高抗油污染性，获得无缺陷、抗污染的超薄平板陶瓷膜。研究浸浆法在超薄平板陶瓷膜支撑体上制备膜层，认识影响膜厚的关键因素，掌握制备膜厚可控、无缺陷超薄平板陶瓷膜的基本原理；利用纳米氧化物修饰薄平板陶瓷膜，在处理含油废水时，降低膜表面与污染物之间的作用强度，掌握提高超薄平板陶瓷膜抗膜污染性的作用规律，并进一步优化超薄平板陶瓷膜处理含油废水的工况。本项目的研究成果，不仅可丰富陶瓷膜分离的相关理论，还将有助于扩大平板陶瓷膜在石油化工、生物医药、环保领域及水处理方面的应用，具有良好的经济和社会效益。

与传统多通道管状陶瓷膜相比，平板陶瓷膜不仅表现为膜构型的转变，由此引起的膜缺陷以及膜的抗污染性的控制问题也具有其独特性。获得无膜缺陷，抗膜污染的超薄平板陶瓷膜是实现其规模工业化应用的基础，其前提是必须认识影响膜厚的关键因素和特定表面性质的膜表面与污染物之间的作用规律。本项目从平板陶瓷的湿膜形成机理和膜表面与污染物之间的作用的角度，研究超薄平板陶瓷膜的成膜过程及其影响因素，获得高性能的平板陶瓷膜；研究平板膜的膜污染过程，通过膜修饰减少膜表面与污染物之间的作用力，为其在油水分离中的应用提供理论支持。本项目开发出喷涂+浸浆法在大孔支撑体上一次烧成制备超滤膜。即首先采用喷涂法在超薄平板陶瓷膜支撑体上制备一层厚度约10μm的膜层，干燥后，将相应的支撑体浸没于高固含量、相对较高粘度的陶瓷浆料中，然后经过干燥和煅烧，获得无缺陷的超滤膜。在平均孔径为4µm，孔隙率为40.4%的超薄平板膜支撑体上，采用相应方法制备出平均孔径为242nm，厚度为30µm的过渡层，采用浸涂法制备出平均孔径为30-58nm的超滤膜分离层，所得超滤膜的纯水通量达到725.74L / (m2 • h • bar)，高出当前所报道的相同（似）孔径的平板陶瓷膜的渗透通量50%。使用该超滤膜处理1g/L的油水乳化液（油滴平均粒径3.63µm），对油的截留率为98.5%，稳定渗透通量180L/(m2•h•bar)，有效抑制了膜污染的形成。本项目共发表学术论文11篇，授权专利7项，培养研究生5名，获得江西省自然科学三等奖1项，项目负责人获得产学研杰出贡献奖。本项目的研究成果，不仅丰富了陶瓷膜的膜形成过程与膜分离过程的相关理论，还有助于扩大平板陶瓷膜在石油化工、生物医药、环保领域及水处理方面的应用，具有良好的经济和社会效益。