| A hollow fiber Micro-filtration Membrane of Ploy (phthalazinone ether sulfone ketone)(PPESK) was chosen to filter the bacteria from soy sauce which is untreated by heat, insteadof "High temperature treated - Long time placed - Multifiltration" in traditional treatment.The effect of bacteria separation was studied, and also the operating conditions (such aspressure, temperature and time) and operation manners (such as membrane modules colludedconnected), which contribute to the definition of the optimal operation conditions. It showsthat the separation rate of bacteria from soy sauce is 100％-no matter in what operationconditions; The optimal conditions are pressure of 0.07 MPa, and temperature could bechosen in a wide period, 20～85℃. Permeation flux declined smoothly; Inner-presses andabreast-connected operating manners help attending good membrane function and longusing-age.Using different cleaning methods - cold water, hot water, steam and acid/alkali lye torevive used membrane modules, which were used to filter the bacteria from soy sauce. Theback-washing conditions (such as back-washing time) were studied, and also the effect ofcleaning. It shows that all the back-washing methods worked well and the permeation fluxrecovering rate of all reached 100％, except hot-water back-washing which is 96.9％. The bestoperating time is 7-10min for steam back-washing, and 30-40min for the others. Steamback-washing is concluded the best one for its less-time-required and food-safety. PPESKmembrane shows well anti-fouled, anti-heated, anti-chemical-destroy ability, multi-operationability and other good abilities.According to the need of the filter-system, test some basic ability of PPESK membrane,such as anti-high-temperature-ability, anti-chemical-destroy ability and long time-kept ability.Soak the hollow fiber membranes in several kinds of solutions for different period of time,then test their pure-water permeation flux to prove their basic ability. The PPESK membranesshows good steady ability in NaClO(＜11000ppm), HCl(PH=2) and NaOH(PH=10) solutions,but not good anti-ability in high concentration NaClO (＞11000ppm) solutions, in which theirpermeation flux rise a lot. The magnitude of membranes became larger in 75％C2H5OHsolutions, but the construction of membrane pore was not destroyed. And for more, PPESK membrane can be well kept in pure water, filterated soy sauce, 20％NaCl and 1％NaHSO4solutions, the permeation flux remained on their original or lower level.This PPESK Micro-filtration membrane is concluded of good anti-fouled, anti-heated,anti-chemical-destroy ability long using age and other good abilities in the whole experiment. |
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