Preparation Of Cationic And Anionic Starch Resin And Its Adsorption On Dyes In Printing And Dyeing Wastewate

In this paper,two corn starch based dye adsorption materials with different properties were prepared from starch by different methods: non degradable anionic starch resin(ASR)and cationic starch straw composite resin(CSCR)used to replace synthetic ion exchange resin and activated carbon.The synthetic process,physical and chemical properties,static and dynamic adsorption of dyes were systematically studied.ASR is an anionic starch resin with carboxylic acid group,which is mainly used to remove cationic dyes(methylene blue,basic fuchsin,malachite green)from wastewater.It is obtained by graft copolymerization with corn starch as matrix,acrylic acid(AA)and vinyl acetate(VAc)as reaction monomers.ASR has good mechanical properties,physicochemical properties,adsorption and regeneration properties.It shows excellent adsorption properties compared with raw starch in the range of p H(4-10).In the static adsorption,the adsorption capacity of methylene blue,basic fuchsin and malachite green reached 18.01 mg/g,17.35 mg/g and 16.65mg/g.After eight regeneration cycles,the decolorization rate was still 77.63%,which was not lower than 90.05% of the first adsorption.CSCR is a cationic starch straw composite resin with quaternary amino group,which is mainly used to remove anionic dyes(reactive dyes and direct dyes)from wastewater.At the same time,the mechanical properties are greatly improved by the addition of straw reinforced particles,which can be used for dynamic(column bed)adsorption.It is blended with raw starch(RS)and reed straw by aqueous phase synthesis,with monomers dimethyl diallyl ammonium chloride(DAC)、 2-methacryloyloxyethyl trimethylammonium chloride(DMC)and methacrylic acid βIt was prepared by graft copolymerization of hydroxyethyl ester(HEMA)and styrene(ST).The structure and surface properties of CSCR were characterized by physical characterization.The results show that CSCR has excellent physicochemical stability and thermal stability,and has strong resistance to acid,alkali and enzyme solutions.In the static adsorption test,the decolorization rate(DR)of mixed dyes in wastewater is as high as 89.13%,much higher than 201 × 7 DR of ion exchange resin(201× 7,DR=38.53%).In the dynamic adsorption test,the DR of CSCR column bed is 99.95%,the wastewater treatment capacity is 45 times of the column volume,and the regeneration performance is excellent.The results show that both anionic starch resin(ASR)and cationic starch straw composite resin(CSCR)have good mechanical and chemical stability.They have good removal properties for cationic dyes(methylene blue,basic fuchsin,malachite green)and anionic dyes(reactive dyes and direct dyes)respectively.They can be applied to different types of printing and dyeing wastewater,so it has a broader application prospect in water treatment.