Study On The Preparation And Dye Adsorption Properties Of Microcrystalline Cellulose-based Composite Materials

The wide use of dyes in the textile industry is causing serious water pollution.The researchers have developed various adsorbents for the treatment of dye wastewater.However,the adsorbent must be low-cost,renewable,biodegradable and have good dye adsorption properties.In view of this,in this study,the cross-linked microcrystalline cellulose-epichlorohydrin composite materials(MCC-EPH)were designed by using the natural source polymer materials?microcrystalline cellulose(MCC)as the skeleton and epichlorohydrin(EPH)as the cross-linking agent;the magnetic cross-linked MCC composite materials(MCC-EPH:Fe₃O₄ mass ratio=5:1?7:1?9:1)were prepared by coating Fe₃O₄ on the surface of MCC-EPH by using co-precipitation method.FT-IR,XRD,BET,TGA,SEM and Zeta potentiometer were used to characterize the structure of the materials and to confirm the successful preparation of MCC-EPH and Fe-MCC-EPH.In this study,the effects of adsorbent dosage,p H,initial dye concentration,temperature,ion strength and adsorption time on the Reactive Blue 4(RB4)and Reactive Red 2(RR2)adsorption capacity of MCC-EPH were investigated.The results showed that the maximum adsorption capacity of RB4 and RR2 was 69.79 mg/g and33.48 mg/g,respectively,the adsorption equilibrium time was just 20 min and 60 min,respectively.The adsorption kinetics data fitted the pseudo-second-order kinetic model well and the adsorption data followed the Langmuir isotherm model.The results of the thermodynamic analysis suggested that the adsorption process was spontaneous and exothermic.The electrostatic interaction was found to dominate in the adsorption process.Regeneration experiments showed that MCC-EPH continued to exhibit good adsorption performance after five cycles of regeneration.In this study,the adsorption properties of Congo Red(CR)between Fe-MCC-EPH and MCC-EPH were compared.The results showed that Fe-MCC-EPH had the best adsorption performance when the mass ratio of MCC-EPH:Fe₃O₄=7:1.The effects of Fe-MCC-EPH on the adsorption properties of CR were studied.Under the best experimental conditions,the maximum adsorption capacity of CR was 215.04 mg/g and the adsorption equilibrium time was 360 min.The pseudo-second-order kinetic model and the Langmuir isotherm model fitted the adsorption data well,respectively.The results of the thermodynamic analysis suggested that the adsorption process was spontaneous and exothermic.Regeneration experiments demonstrated the good reusability of the Fe-MCC-EPH.The adsorption performance of Fe-MCC-EPH on Methyl Blue(MB)was preliminarily investigated,the maximum adsorption capacity was 51.93 mg/g,and the adsorption equilibrium time was only 80 min.MCC-based composite materials prepared in this study have the advantages of low cost,renewable,biodegradable,and good dye adsorption performance,and are expected to be used in the treatment of industrial dye wastewater in the future.