Decolorization process of D-galactose crystallization mother liquor
During the industrial production process of D-galactose,a large amount of mother liquor is generated,which contains a large amount of D-galactose.The yield of D-galactose products can be improved by recycling and utilizing the mother liquor,and the discharge of waste liquid can be reduced.The composition of D-galactose mother liquor is complex and the color is dark brown.Decolorization and impurity removal treatment must be undergo to achieve recycling.A resin activated carbon combined decolorization method was established to obtain high-performance resins,and optimize decolorization and resin regeneration conditions.The results showed that the combination of HYA-310 resin and ZX-301 activated carbon had the best decolorization effect in the conditions of mother liquor pH 3.0,total sugar concentration 90 g/L and the volumetric flow rate of sample solution 0.5 mL/min.The transmittance of mother liquor exceeded 90%after decolorization.The regeneration of decolorizing resin using saturated NaCl resulted in a resin exchange capacity recovery rate of 91.2%,which can be reused more than 10 times.The yield of D-galactose in the mother liquor reached 60%,while the purity of the D-galactose product exceeded 98%in the process.