死端搅拌操作条件下平均膜污染度量指数变化

Variation of Average Membrane Foulant Index Under Dead-End Agitation Operation

在死端搅拌微滤膜装置上,采用0.1μm孔径的PES平板微滤膜对酵母悬浮液进行过滤实验。研究瞬时膜污染度量指数(t)和平均膜污染度量指数■在不同操作条件下(搅拌速率、浓度、温度、压力和污染物)的变化规律。结果表明,搅拌速率200 rmp时(t)最小,而■随搅拌速率的增加先增大后降低;在浓度、温度以及压力下,(t)均随时间递增,■随浓度递增。另外,■(酵母悬浮液)>■(活性污泥悬浮液)>■(高岭土悬浮液)则说明在实际过滤过程中,选择2 g/L、25℃和0.08 MPa作为固定操作条件,选择尽可能高搅拌速率和低料液浓度的高岭土悬浮液时的膜污染程度最轻。

Yeast suspensions were fouled using PES flat microfiltration membrane with a diameter of 0.1μm in a dead end stirred microfiltration membrane device.The variation of instantaneous membrane fouling indexφ(t)and average membrane fouling index■under different operating conditions(stirring rate,concentration,temperature,pressure and foulants)were studied.The results show that(t)is the smallest at 200 rmp stirring rate and increases first and then decreases with the increase of stirring rate,while(t)increases with time and concentration under concentration,temperature and pressure.In addition,■(yeast suspension)>■(activated sludge suspension)>■(kaolin suspension)indicated that in the actual filtration process,2g/L,25℃and 0.08 MPa were selected as the fixed operating conditions,and kaolin suspension with the highest stirring rate and low feed liquid concentration as possible would have the lightest membrane pollution degree.