Synthesis And Adsorptive Property Of Cellulose Derivatives

Recently years, the water environment pollution caused by the heavy metals and organic dyes hasbecome a serious problem for human health. Adsorption is a reliable method, as its simplicity, highefficiency and able to handle multiple types of pollutants. So the development of environmental friendlyadsorbent with high adsorption capacity, low cost is significant.In this paper, a series of adsorbents EMC, CMC and CMS were developed with cellulose as carrier,they were characterized by FTIR, TGA, DTA, XRD and XPS, respectively. They were used for theadsorption of the metal ions and organic dyes. In the adsorption capacity experiments, the effects of varyingparameters such as pH, contact time, temperature and initial concentration on the adsorption process wereexamined; the kinetic study and adsorption isotherm in the adsorption process were evaluated. The mainresults are as follow:1. The chemically modified cellulose （EMC） was grafted with vinyl monomer glycidyl methacrylateand calix[4]arene, and used to uptake Ca （Ⅱ） from aqueous solution. The adsorption process, which was pHdependent, shows maximum removal at pH7.0. Adsorption equilibrium was achieved within60min. Themaximum adsorption capacity of Ca （Ⅱ） reached104.16mg g^-1.The adsorption process fit the Langmuirisotherm and the pseudo-second-order kinetics model.2. The CMC adsorbent, which was synthesized by modified cellulose with thiosemicarbazide, andused for the adsorption of Hg （Ⅱ）, Cd （Ⅱ） and acid fuchsin from their aqueous solutions. Adsorption resultsshow that CMC could be efficiently used for adsorption of Cd （Ⅱ）, Hg （Ⅱ） and acid fuchsin from aqueoussolutions. The adsorption rate was encouraging and adsorption equilibriums were obtained within120min.The kinetics adsorption data could be well fitted with pseudo-second-order kinetic model. The equilibriumdata of Cd （Ⅱ） and AF can be well fitted with the Langmuir isotherm model, while the equilibrium data ofHg （Ⅱ） is well fitted with the Temkin isotherm model. The maximum adsorption capacity of Cd （Ⅱ） and AFreached279.33mg g^-1and105.71mg g^-1, respectively; while the adsorption capacity of Hg （Ⅱ） could reach505.50mg g^-1when the initial concentration of Hg （Ⅱ） is0.04mol L^-1. Batch recycling of CMC wasconduced and the results confirmed that the sorption capacity of CMC was encouraging by the regeneration process.3. We synthesized the adsorbent CMS by introduce dicyandiamide onto the surface of cellulose, andthe adsorbent was used to remove methyl orange. The experiment results show that adsorption equilibriumswere obtained within120min at the optimum conditions. The adsorption capacity of methyl orange couldreach213.22mg g^-1. The adsorption process fit the Langmuir isotherm and the pseudo-second-orderkinetics model.