摘要
采用管式膜微滤高岭土悬浊液,考察了恒通量下曝气对膜污染的影响,并对不同膜面气体流速下跨膜压力和膜污染周期变化进行了研究,此外,采用阶梯通量法对临界通量进行了测定。结果表明,曝气可显著减缓膜污染,延长膜污染周期,同时提高膜的临界通量;随着膜面气体流速由0.067 m·s^(-1)提升至0.251 m·s^(-1)时,膜污染平均速率由0.366 k Pa·h^(-1)降低至0.104 k Pa·h^(-1),膜污染周期由8 d延长至31 d,临界通量由8~10 L·(m^2·h)-1提高至22~26 L·(m^2·h)-1。此外,通过惯性模型分析发现,膜的临界通量与膜面混合流速呈良好的线性关系,R^2=0.98;但随着膜面气体流速的增加,悬浊液中高岭土粒径逐渐变小,并且通过膜表面污染阻力构成分析发现,膜表面不可逆污染阻力由13.9%提高至31.6%,这不利于膜污染控制。
The effect of aeration on membrane fouling under a constant permeate flux was researched for a tubular membrane filtering a kaolin suspension. Variations in transmembrane pressure（ TMP） and membrane operation time under different superficial gas velocity were also investigated. The critical flux was also identified by incrementing the flux until TMP was no longer steady. The results showed that aeration could significantly alleviate membrane fouling,prolong membrane operation time,and also enhance the critical flux of the membrane. The average membrane fouling rate was reduced from 0. 366 to 0. 104 k Pa·h^-1 and the average operation time increased from 8 to 31 d when the superficial gas velocity increased from 0. 067 to 0. 251 m·s^-1. Concurrently,the critical flux increased from 8 to 10 to 22 to 26 L·（ m^2·h）-1. In addition,the inertial lift model for critical flux determination indicated that the critical flux had a linear relationship with the superficial mixture velocity（ R^2= 0. 98）. However,with increase in the superficial gas velocity,the kaolin particle size became smaller and the ratio of irremovable resistance increased from 13. 9% to 31. 6%. This condition may be not conducive to membrane fouling control.
出处
《环境工程学报》
CAS
CSCD
北大核心
2017年第8期4542-4548,共7页
Chinese Journal of Environmental Engineering
基金
"十二五"国家科技支撑计划项目(2014BAE06B00)
关键词
曝气
膜污染
临界通量
污染阻力分析
aeration
membrane fouling
critical flux
membrane resistance analysis
