曝气量对混凝/气提/超滤膜组合工艺膜污染的影响

Influence of Aeration Rates on Membrane Fouling in Coagulation / Bubbling /Ultrafiltration Process

在超滤前进行混凝预处理可以减轻膜污染,混凝/超滤组合工艺已得到广泛的认可。在混凝/超滤工艺中引入曝气,形成了混凝/气提/超滤组合水处理新工艺。通过试验分析不同曝气量条件下的跨膜压差(TMP)、膜污染总阻力(Rt)以及膜污染指数(UMFI),探讨了不同曝气量下的膜污染情况。结果表明,混凝和曝气有利于减轻膜污染;并且随着曝气量的增加,TMP和Rt增长速率呈降低的趋势,UMFI值也逐渐减小。当曝气量从零增加到180 m L/min时,TMP和Rt的平均增长速率分别从0.211 k Pa/h和0.037×1012m^(-1)/h降低至0.065 k Pa/h和0.026×1012m^(-1)/h,UMFI值从0.001 18 m^2/L降低至0.000 30 m^2/L,膜污染程度显著降低。

Since coagulation pretreatment can effectively reduce membrane fouling, coagulation/ uhrafiltration process has been widely recognized. A novel combined process of coagulation, bubbling and ultrafiltration was developed by introducing aeration into the coagulation/ultrafihration process. The trans- membrane pressure （TMP）, total resistance （Rt ） and unified membrane fouling index （UMFI） under different aeration rates were analyzed through tests, and membrane fouling under different aeration rates was also discussed. The results showed that coagulation and aeration contributed to the reduction of mem- brane fouling. In addition, the increase rate of TMP and Rt slowed down and the value of UMFI decreased as aeration rate increased. When aeration rate increased from 0 to 180 mL/min, the average in- crease rate of TMP and R1 reduced from 0. 211 kPa/h and 0. 037×10^12m^-1/h to 0. 065 kPa/h and 0.026×10^12m^-1/h respectively, and UMFI value decreased from 0.001 18 m^2/L to 0.000 30 m^2/L.The reduction of membrane fouling was remarkable .