一体式光催化—膜分离反应器的研究

【作者】 王能亮；

【导师】 解立平；

【作者基本信息】 天津工业大学 ， 环境工程， 2008， 硕士

【摘要】 本文通过对有机膜分离技术与光催化技术的耦合,设计了一体式光催化氧化一膜分离三相流化床反应器;并采用u型PVDF中空纤维膜,通过对以工业级TiO₂光催化氧化降解低浓度Acid Red B模拟废水的实验,对一体式反应器的性能进行了研究。实验结果表明:本实验系统中适宜的运行条件为:TiO₂浓度2g/L,Acid RedB浓度为10 mg/L,pH值控制在2.5,膜通量为15 L/h,膜丝底部曝气量0.6 m³/h,反应区曝气量为3.6 m³/h。当采用光源为350 W紫外高压汞灯时,反应器预反应时间为2 h时;一体式反应器连续运行120 h膜出水脱色率稳定在90%以上。膜丝底部曝气可有效地提高膜丝表面的错流率,对减缓膜污染有明显效果,反应区适宜的曝气量不仅可保证反应器内催化剂呈良好的悬浮状态,同时还可使膜分离区的紊流程度加强,有利于减缓膜污染。在酸性及碱性条件下有利于减缓膜污染,膜污染的主要影响因素是催化剂,且随TiO₂浓度增加膜污染变的严重。采用在线反冲的清洗方式可以保证反应器长期、稳定地运行,且采用“表面冲洗+碱洗+碱液反冲”相结合的清洗方式可以使污染后的膜通量恢复到99%以上。更多还原

【Abstract】 An new kind of integrative reactor, coupling with the technologies of organic membrane separation and photocatalytic oxidation, was designed. The fundamental performance of the reactor are investigated by photocatalytic degrading Acid red B wastewater with TiO₂ which the average granularity diameter is 0.258μm, the membrane module is U-shape PVDF hollow fiber membrane.The results show that the best operating conditions are as follows: the concentration of TiO₂ and Acid Red B is 2 g/L, 10 mg/L respectively, the pH value is 2.5, aeration rate is 3.6 m³/h, membrane fluxation is 15 L/h, aeration flux bellowing the hollow fiber membrane is 0.6 m³/h. When the light source is uvtraviolot light that is 350 W, the pre-reactor time is 2 h. The decolourization efficiency of the waste water can reach as higher as 90% during the integrative reactor runing in 120 h.Membrane fouling rate can be controlled greatly with bubbling under membrane module and bellow reactor, because of cross-flow rate on face of the membrane and turbulence is enhanced. Membrane fouling rate can be decreased in the conditions of acidic and alkaline.The main factor which cause membrane fouling is TiO₂, and membrane fouling become serious with TiO₂ concentration increasing. guarantee The reactor can run in a long and stable way in the condition of backwash online. Alkaline-backwash after face-wash followed by alkaline rising can make the membrane flux recover to 99%.更多还原