陶瓷膜管外壁预涂动态膜形成特性研究_杨涛

Studyontheformationcharacteristicsofthedynamicmembranepre-coatedontheoutsidewallofceramicmembranetubesYangTao1，2，YangQiyong2，MaZhengfei1（1.CollegeofChemistryandChemicalEngineering，NanjingUniversityofTechnology，Nanjing210009，China；2.SchoolofChemistryandChemicalEngineering，JiujiangUniversity，Jiujiang332005，China）陶瓷膜管外壁预涂动态膜形成特性研究杨涛1，2，杨期勇2，马正飞1（1.南京工业大学化学化工学院，江苏南京210009；2.九江学院化学化工学院，江西九江332005）［摘要］以错流外压方式在陶瓷膜管外壁面制备高岭土预涂动态膜，讨论了跨膜压差、涂膜液浓度、错流速度及操作温度对膜通量、涂膜量及吸附层与动态膜层阻力比的影响。结果表明：高错流速度下形成的动态膜层较密实，适合处理含细小颗粒物的废水；高压跨膜差下涂膜容易造成基膜的污染；低跨膜压差及高涂膜液浓度下需要较长的涂膜时间，跨膜压差在0.15~0.25MPa范围内较适宜；低涂膜液浓度下形成的动态膜层较薄，抗污染性能较差，涂膜液质量浓度在0.3~0.4g/L下较合适；升高温度易使高岭土颗粒物向陶瓷膜管外壁面沉积和孔内扩散，其中较大高岭土颗粒物更容易向陶瓷管外壁面沉积，形成较松散的动态膜层。［关键词］动态膜；预涂；基膜；陶瓷膜［中图分类号］X703.1；TQ028.8［文献标识码］A［文章编号］1005-829X（2010）06-0037-04Abstract：Thekaolinpre-coateddynamicmembraneontheoutsidewallsofceramicmembranetubeshasbeenpre-paredbycross-flowandoutside-inways.Theimpactsoftransmembranepressuredifference，coatingsolutioncon-centration，cross-flowvelocityandoperationtemperatureontheflux，themassofdynamiclayer，theresistanceratiobetweenabsorbedlayeranddynamiclayerarediscussed.Theresultsshowthatthedynamicmembraneformedinthehighercross-flowvelocityismorecompactandsuitablefortreatingthewastewatercontainingsmallparticles.Itiseasytofoulthesubstratedmembraneathighertransmembranepressuredifference.Itneedsmoretimetoformastabledynamicmembraneatlowertransmembranepressuredifferenceandhigherconcentrationofthecoatingsolu-tion.Thesuitablerangofthetransmembranepressuredifferenceis0.15-0.25MPa.Thethinnerdynamiclayerwithpoorantifoulingcharacteristicsisformedinthecoatingsolutionwithlowerconcentration.Thesuitablerangoftheconcentrationofthecoatingsolutionis0.3-0.4g/L.Asthetemperatureincreases，thekaolinparticlesareinclinedtodepositontotheoutsidesurfaceoftheceramicmembranetubesanddiffuseintheholes，andespeciallythebiggerparticlesareeasiertodepositontheoutsidesurfacesoftheceramictubes，forminglooserdynamicmembranelayers.Keywords：dynamicmembrane；pre-coated；substratemembranes；ceramic