The Study And Application Of Novel PPESK Enzymatic Membrane Reactor

As an interacross research of many subjects, enzymatic membrane reactor(EMR)combines the high catalytic activity of bio-enzyme and permselectivity of separationmembrane.EMR achieves the simultaneous process of reaction and separation,displayingsuper production efficiency.Hollow fiber ultrafiltration membranes are fabricated using novelhigh performance heterocylic poly (phthazinone ether sulfone ketone)(PPESK) as membranematerials.Based on this work,EMRs are designed and studied systemically.The realativeexperiments and results are summarized as follow.Hollow fiber ultrafiltration membranes are prepared successfully from PPESK with adry/wet inversion technique.With the requirements of different kinds of EMRs,propermembrane formulations and preparation processes are confirmed.Based on the above work,recirculated enzymatic membrane reactors(REMRs) aredesigned,using for preparation of 5'-nucleotide on the hydrolysis of RNA. The effects ofreaction time,concentration of RNA, concentration of enzyme,temperature and pH on thehydrolysis are studied.The reasons why RNA hydrolyze uncompletely are discussed.Theexperimental results show that,after running 5 hours,the yield of hydrolysis of RNA achieves85% when the concentration of substrate,concentration of nuclease P1,pH,temperature,transmembrane pressure are 2%(w/v),100ppm,5.2, 65℃, 0.1MPa,respectively. The fouledmembranes are cleaned by hot alkali rinsing and the recover ratio of water flux isapproximately approach new membranes.Formed-in-place Membranes are prepared with modified Negrel's procedule.Theexperimental results indicate that the dynamic state method is superior to the state method onthe process of tanning. The effects of gelation filtration time,concentration of glutaradehydeand tanning temperature on the performance of Formed-in-place Membranes are discussed.The condition of protein deposition and tanning process are confirmed,with the 10g/l gelationsolution filtrating for 20 minutes and 2%(w/v) glutaradehyde solution tanning at 35℃.By theway,membrane cleaning and regeneration with hot alkali rinsing and acid rinsingcontinuously shows outstanding results.Dialdehyde starch(DAS),a kind of novel cross linker,is prepared by two differentmethods:hetegeneous phase method and virtual homogeneous phase method,respectively.Theeffect of reaction time,temperature,pH and feeding ratio on the oxidizability of DAS are investigated.The experimental results show that DAS prepared by virtual homogeneous phasemethod in low temperature avoids side effect of over-oxidation.Moreover,it has relative highreaction speed and ideal oxidizability.