以钛酸丁酯为前驱体,采用酸性溶胶法在低温下(<100oC)制备了纳米级TiO2粉末,X射线衍射分析表明,样品为锐钛矿型,晶粒尺寸为3.6nm.以250W紫外灯为光源,在自制悬浮式光催化膜反应器中进行降解活性艳红X-3B有机染料废水实验,采用尼龙6(N6)和混合纤维素(CN-CA)两类微滤膜对TiO2颗粒进行截留分离.综合考察了影响光催化和膜分离效率的因素.结果表明,反应起始pH值和催化剂用量对光催化膜反应器运行性能影响很大,该耦合体系的最佳pH值为4,染料和催化剂最佳浓度比为2:1,0.45和0.22μm的CN-CA膜对TiO2颗粒截留率可达96.5%以上.
Nano-titania was prepared by an acid-sol method at low temperature (<100 oC) using tetrabutyl titanate as the precursor. X-ray diffraction analysis showed that the TiO2 sample was anatase and had a particle size of 3.6 nm. The wastewater containing reactive brilliant red X-3B was subjected to photocatalytic degradation with the titania and UV light in a slurry photocatalytic membrane reactor (PMR), where titania particles were separated by microfiltration membranes Nylon 6 (N6) and mixed fibroid membrane of cellulose nitrate and cellulose acetate (CN-CA). The photocatalysis efficiency and membrane separation processes were investigated in detail. The results showed that initial pH and TiO2 dosage significantly influenced the performance of PMR. The optimum pH was 4, and the best dosage rate of dye to photocatalyst was 2:1. Among the membranes tested, both CN-CA 0.45 μm and 0.22 μm held removal rate above 96.5% for titania.