聚偏氟乙烯中空纤维膜蒸馏性能研究  

STUDY ON PERFORMANCE OF PVDF HOLLOW FIBER MEMBRANE DISTILLATION

作　　者：吴刚[1] 武春瑞[1] 吕晓龙[1] 

机构地区：[1]天津工业大学中空纤维膜材料和膜过程教育部重点实验室,天津工业大学生物化工研究所,天津300160

出　　处：《水处理技术》2008年第5期20-23,32,共5页Technology of Water Treatment

基　　金：国家科技支撑计划项目海水淡化与综合利用成套技术研究和示范专项课题(2006BAB03A06);天津市重大科技攻关项目(05YFGDGX10000)

摘　　要：采用疏水性聚偏氟乙烯(PVDF)中空纤维微孔膜,以3.5%的NaCl水溶液为测试液,进行直接接触膜蒸馏(DCMD)脱盐过程研究。考察了盐水温度、流速、PVDF膜的壁厚、内径、组件长度及封装分率等因素对DCMD过程性能的影响。结果表明:盐水温度、流速提高都有利于提高DCMD过程的通量;随中空纤维膜壁厚增加,通量逐渐降低;内径从0.5mm增加到1.0mm,通量略有提高,且壁厚较薄的膜,内径变化对通量的影响较明显;膜组件长度、装填分率增加,产水通量降低但组件产水总量提高。截留率受操作条件、膜和组件结构的影响较小,基本保持在99.99%,产水电导率<4μS/cm。Hydrophobic polyvinylidene fluoride （PVDF） hollow fiber microporous membranes were employed in direct contact membrane distillation （DCMD） process for the desalination of 3.5wt% NaCI aqueous solution. The main factors,such as the feed temperature, flowing velocity, the thickness of the membranes, the inner diameter of the hollow fibers, the length and packing fraction of fibers in modules were studied. The results showed that the permeate flux of DCMD process increased obviously with the enhancement of feed temperature and flowing velocity, but decreased with the increase of membrane thickness. As the inner diameter of the fibers increased from 0.5mm to 1.0mm, the flux only showed a minor enhancement. The permeate flux decreased but the total water production increased as the length and the packing fraction of the modules increased. The rejection for NaCI was sta- ble and kept at 99.99%, and the conductance of the product water was lower than 4μS/cm in all the experiments.

关 键 词：直接接触膜蒸馏(DCMD) 聚偏氟乙烯(PVDF) 中空纤维膜 疏水微孔膜 脱盐 

分 类 号：TQ028.8[化学工程]