The Study Of Prepare Composite Nanofiltration Membrane To High Efficent Separation Of Monosaccharides And Two Sugar

Somewhere between ultrafiltrationand reverse osmosis nanofiltration membrane technology in rapid development in recent years, the research on NF membrane has become a hot topic of great value, appearance of nanofiltration membrane materials at home and abroad market. At present, there are a lot of research about using interfacial polymerization to prepare polyamide composite nanofiltration membrane in the domestic and foreign. The research emphasis is on the premise of reasonable rejection rate of NaCl, MgSO4, then increasing the nanofiltration membrane flux or improving the chlorine resistance and contamination resistance. The composite membrane separation efficiency of molecular weight between 300-1000 in different organic matter will be very low.In this paper, for the purpose of separate monosaccharides with disaccharide, exploring the effect of the monomer structure, monomer concentration and additive agent on composite nanofiltration membrane. Composite membranes were prepared through interfacial polymerization of active monomers of PES UF membrane. The effect of monomers in aqueous phase on the surface morphology and separation performance of the composite membrane was studied. The results show that the PIP as monomer in aqueous phase has better separation effect for monosaccharides with disaccharide. And the optimal preparation conditions were determined:the aqueous phase monomer (PIP) concentration was 0.10 (w/v)%,the organic phase monomer (TMC) concentration was 0.30 (w/v)%, Sodium dodecyl sulfate (SDS) concentration was 0.06 (w/v)%,aqueous solution pH value was 9.5,interfacial polymerization time was 60s. The optimal conditions for preparing the composite nanofiltration membrane in the liquid temperature of 45℃ and the pressure under the condition of 0.7MPa, the retention rate of sucrose was 90.1%, the retention rate of fructose was 49.1%, composite nanofiltration membrane flux was 170L/(m2·h).In the monosaccharides and sucrose separation system, the effect of operating conditions on the composite membranes was studied. Nanofiltration membrane better operation conditions were as follows:the material liquid temperature of 45℃.At the same time, the nanofiltration membrane was used in the concentration and purification of inulin solution, the nanofiltration membrane in the liquid temperature of 45℃, operating pressure is 0.5MPa, the flux is 135 L/(m2·h). The content of monosaccharide inulin solution decreased from 6.54% to 4.53% of the original solution by nanofiltration process.