Preparation Of Cellulose Based Adsorbents In Ionic Liquids For Removal Of Heavy Metal Ions

Cellulose is the most abundant natural macromolecular materials on the world, with many advantages such as biocompatible, biodegradable, etc. Hence, the effective use of cellulose resources will be of great importance to relieve the crisis in environment and energy. Ionic liquids, which are considered as "green solvents", can dissolved cellulose effectively without some drawbacks of traditional solvents. A series of cellulose based adsorbents were prepared in 1-ally 1-3-methylimidazolium chloride ([Amim][Cl]) and 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]). We studied their performance to remove heavy metal ionsThe main research work is as follows:(1) Preparation of pure cellulose and cellulose-sodium alginate blends microspheres in [Amim][Cl] and characterized by SEM, XRD analysis.(2) Comprehensive studies of effect of pH, adsorption time,initial concentration of heavy mental ions and recyling. The results indicated that the adsorbent CA2 has good adsorption capacities for Cu2+. The largest adsorption capacity was achived at pH=6 in 12 hours. When the initial Cu2+ concentration was 300 ppm at pH=6.0, the equilibrium adsorption capacity of Cu2+ by CA2 was up to 31.0mg/g. Pseudo-first-order model, pseudo-second-order model and intra-particle diffusion model were employed to fit the adsorption data of Cu2+ on pure cellulose and CAs. The results indicated that pseudo-second-order model is the best-fit kinetics model which showed the adsorption contain chemical process. Langmiur and Freundlich isothermal adsorption models were used to fit the adsorption process.Langmuir model fit better indicating the adsorption was a monolayer adsorption. After 5 times recycling,87.4% of the adsorption capaciy of Cu2+ reserved, which showed the adsorbents were reuseable.(3) On the basis of the above work, magnetic cellulose-sodium alginate blends microspheres(MCA) were prepared with Fe3O4 nanoparticles. MCA microsopheres showed magnetic property that can be used in separation. The adsorption study indicated that When the initial Cu2+concentration was 300ppm at pH=6.0, the equilibrium adsorption capacity of Cu2+by CA2 was up to 27.2 mg/g. The adsorption process was also chemical and monolayer adsorption. After 5 times recyling,81.1% of the adsorption capaciy of Cu2+ reserved.(4) A primary research of cellulose extracted from sugarcane rind was studied. Cellulose from sugarcane rind was grafted homogeneously with acrylic acid in [Bmim][Cl]. Then cellulose adsorbent was prepared and comprehensive studies on the adsorption properties of the cellulose adsorbent was conducted.