Application of the metal membrane filtration in the pretreatment of 1,3-propanediol broth

At the different concentration rate the change of quasi-steady filtrate flux,viscosity and wet solid content for 1,3-propanediol fermentation broth were investigated by metal membranes.On the basis of this,the mechanism of membrane fouling was pre-investigated and the method of membrane cleaning was obtained.It showed that 50 nm membrane was suited for membrane filtration of 1,3-propanediol fermentation broth.The recovery rate could be improved to 95% by adding 35% of the dieonized water,the concentration ratio of about 9.The major source of membrane pollution was protein and effective chemical method of cleaning was that it took 40 minutes to clean membranes by mixed solution composed of 1% NaOH and 0.05% EDTA,whereafter,0.5%HNO3 was used to clean membrane for 5 minutes.The results indicated that membrane flux could be recovered rapidly.