外压浸入式超滤膜反洗方式研究

Study on Backwash Method of External Pressure Submerged Ultrafiltration Membrane

气水反冲洗是外压浸入式超滤膜去除膜污染的主要措施,采用此膜处理供水厂的生产废水,考察了反洗液位、反洗方式、反洗强度及反洗时间等因素对去除膜污染的影响。结果表明,若要达到理想的反冲洗效果,反洗时膜池内的液位要高于膜组件,且气洗时间≥30 s、水洗时间≥20 s;气水同时反冲洗的效果要优于单独气洗或水洗。综合考虑反冲洗效果、用水量和能耗等因素,确定最佳的反洗模式为先单独气洗20 s、然后气水同时反冲洗20 s,其中气洗强度为143 L/(m2.h)、水洗流量为3.5 t/h。

Air-water backwashing is the main way to remove fouling of external pressure submerged ultrafiltration membrane. This membrane was used to treat production wastewater from waterworks, and the effects of factors, such as backwashing liquid level, methods, intensity and time on removal of mem- brane fouling were investigated. The results show that to achieve an ideal backwashing efficiency, the liquid level of reactor should be higher than that of membrane module, the air-backwashing time should be no less than 30 s and the water-backwashing time no less than 20 s. The efficiency of simultaneous air- water backwasbing is better than that of air-backwashing or water-backwashing alone. Taking the back- washing efficiency, water and energy consumption into account, the optimal backwashing mode is deter- mined as follows ： first, air-backwashing is 20 s, and then simultaneous air-water backwashing is 20 s, in which air-backwashing intensity is 143 L/（m^2· h） , and water-backwashing rate is 3.5 t/h.