【摘要】 改变曝气强度是控制SMBR(Submerged Membrane Bioreactor)膜污染的重要手段之一.在不同的曝气强度下考察了膜过滤压差随时间的变化情况,膜阻力构成情况和污泥指数SVI(Sludge Volume Index)的变化对膜污染的影响.结果表明:曝气强度过大或过小,压差上升速率都会增大;随着曝气强度的增大,Rp,Ref,Rc在过滤总阻力中所占的比例都会逐渐减小,Rif在过滤总阻力中所占的比例逐渐增大;当曝气强度低于0.88 m3.m-2.h-1时,水力剪切力主要作用于膜污染的消除,而对活性污泥的性质没有多大影响,SVI变化不大,因此压差上升速率随曝气强度的增加而降低;而当曝气强度高于0.88 m3.m-2.h-1时,水力剪切力过大,导致污泥絮体结构被破坏,SVI明显增大,从而加速了膜的污染,使压差上升速率随曝气强度的增加而增加.更多还原

【Abstract】 Changing aeration intensity is one of the important measures to control membrane fouling of Submerged Membrane Bioreactor(SMBR).Under different aeration intensity,variation of membrane filtration pressure with time and the distribution of the membrane filtration resistance,as well as the influence of SVI changing on membrane fouling,were researched.Experimental results indicated that pressure increasing rate could increase when aeration intensity was either too high or too low.With aeration intensity increasing,the proportion of Rp,Ref and Rc in the total filtration resistance gradually decreased,but the proportion of Rif increased.When aeration intensity was less than 0.88 m3·m-2·h-1,hydraulic shear mostly removed membrane fouling,but had little effect on activated sludge,SVI changed little,so pressure increasing rate decreased as aeration increased.When aeration intensity was more than 0.88 m3·m-2·h-1,activated sludge floc was destroyed because of too high hydraulic shear,SVI obviously increased,consequently membrane fouling was worsened,pressure increasing rate increased as aeration intensity increased.更多还原