A novel biosorbent was developed by coating chitosan, a naturally and abundantly available biopolymer, on to activated alumina based on oil shale ash via crosslinking. The adsorbent was characterized by various techni...A novel biosorbent was developed by coating chitosan, a naturally and abundantly available biopolymer, on to activated alumina based on oil shale ash via crosslinking. The adsorbent was characterized by various techniques, such as Fourier transform infrared spectroscopy, scarming＇ elec.tron micros cop.y, the rmogravimetric-differentialthermal analysis, and X-ray photoelectron spectroscope. Batch isothermal equilibrium adsorption experiments were condcted to evaluate the adsorbent for the removal of Cu（Ⅱ） from wastewater. The effect of pH and agitation time on the adsorption capacity was also investigated, indicating that the optimum pH was 6.0. The equilibrium adsorp-tion data were correlated with Langmuir and Freundlich models. The maximum monolayer adsorption capacity of chitosan coated alumina sorbent as obtained from Langmuir adsorption isotherm was fotmd to be 315.46 mg.g-1 for Cu（Ⅱ）. The adsorbent loaded with Cu（Ⅱ） was readily regenerated using 0.1 mol.L-1 sodium hydroxide solution. All these indicated that chitosan coated alumina adsorbent not only have high adsorption activity, but also had good stability in the wastewater treatment process.展开更多
Porous chitosan（CS）/magnetic（Fe304）/ferric hydroxide（Fe（OH）3） microsphere as novel and low-cost adsorbents for the removal of As（Ill） have been synthesized via the electrospraying technology by a simple proc...Porous chitosan（CS）/magnetic（Fe304）/ferric hydroxide（Fe（OH）3） microsphere as novel and low-cost adsorbents for the removal of As（Ill） have been synthesized via the electrospraying technology by a simple process of two steps. Characterization of the obtained adsorbents was studied by transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, X-ray photoelectron spectroscopy （XPS）, and X-ray diffraction （XRD）. The adsorption kinetics and equilibrium isotherms were in- vestigated in batch experiments. The Langmuir, Freundlich isotherm and pseudo-second order kinetic models agree well with the experimental data. The adsorption of As（III） onto CS/Fe3OdFe（OH）3 microspheres occurred rapidly and reached adsorption equilibrium after about 45 min. The maximum adsorption capacity of CS/Fe3OJFe（OH）3 microspheres, calculated by the Langmuir isotherm model, was 8.47 mg g 1, which is higher than that of CS/Fe304/Fe（OH）3 prepared by the conventional method （4.72 mg g-l）. The results showed that the microspheres had a high adsorption capacity for As（III） and a high separation efficiency due to their microporous structure and superparamagnetic characteristics. Present research may eventually lead to a simple and low cost method for fabricating microporous materials and application for removal of arsenic from aqueous solution.展开更多
基金Supported by the National Innovative Projects with Cooperation in terms of Production,Study and Research (OSR-05)the National Science and Technology Major Projects (2008ZX05018-005)
文摘A novel biosorbent was developed by coating chitosan, a naturally and abundantly available biopolymer, on to activated alumina based on oil shale ash via crosslinking. The adsorbent was characterized by various techniques, such as Fourier transform infrared spectroscopy, scarming＇ elec.tron micros cop.y, the rmogravimetric-differentialthermal analysis, and X-ray photoelectron spectroscope. Batch isothermal equilibrium adsorption experiments were condcted to evaluate the adsorbent for the removal of Cu（Ⅱ） from wastewater. The effect of pH and agitation time on the adsorption capacity was also investigated, indicating that the optimum pH was 6.0. The equilibrium adsorp-tion data were correlated with Langmuir and Freundlich models. The maximum monolayer adsorption capacity of chitosan coated alumina sorbent as obtained from Langmuir adsorption isotherm was fotmd to be 315.46 mg.g-1 for Cu（Ⅱ）. The adsorbent loaded with Cu（Ⅱ） was readily regenerated using 0.1 mol.L-1 sodium hydroxide solution. All these indicated that chitosan coated alumina adsorbent not only have high adsorption activity, but also had good stability in the wastewater treatment process.
基金supported by the research grants from the National 973 Project (S2009061009)the National Natural Science Foundation of China(50973038)
文摘Porous chitosan（CS）/magnetic（Fe304）/ferric hydroxide（Fe（OH）3） microsphere as novel and low-cost adsorbents for the removal of As（Ill） have been synthesized via the electrospraying technology by a simple process of two steps. Characterization of the obtained adsorbents was studied by transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, X-ray photoelectron spectroscopy （XPS）, and X-ray diffraction （XRD）. The adsorption kinetics and equilibrium isotherms were in- vestigated in batch experiments. The Langmuir, Freundlich isotherm and pseudo-second order kinetic models agree well with the experimental data. The adsorption of As（III） onto CS/Fe3OdFe（OH）3 microspheres occurred rapidly and reached adsorption equilibrium after about 45 min. The maximum adsorption capacity of CS/Fe3OJFe（OH）3 microspheres, calculated by the Langmuir isotherm model, was 8.47 mg g 1, which is higher than that of CS/Fe304/Fe（OH）3 prepared by the conventional method （4.72 mg g-l）. The results showed that the microspheres had a high adsorption capacity for As（III） and a high separation efficiency due to their microporous structure and superparamagnetic characteristics. Present research may eventually lead to a simple and low cost method for fabricating microporous materials and application for removal of arsenic from aqueous solution.
