Adsorption experiment from aqueous solutions containing known amount of Cr （chromium） using chitosan was explored to evaluate the efficiency of chitosan as sorbent for Cr. Some variable parameters such as pH, reacti...Adsorption experiment from aqueous solutions containing known amount of Cr （chromium） using chitosan was explored to evaluate the efficiency of chitosan as sorbent for Cr. Some variable parameters such as pH, reaction time and chitosan dosage were optimized. Under the optimum experiment condition, the effect of common ions on the adsorption of Cr （i.e., Na^＋, K^＋, Mg^2＋, Ca^2＋ for Cr（Ⅲ）, and Cl^-, NO3^-, SO4^2- for Cr（Ⅵ）） was also investigated. Furthermore, the sorption mechanism of Cr by chitosan was investigated by applying Langmuir and Freundlich isotherm equations to the data obtained. In addition, to confirm the characteristics of the chitosan, the surface morphology of the biomass was determined by SEM （scanning electron microscope） and specific surface area analyzer （N2-BET （Brunaeur, Emmet and Teller））. Consequently, the following matters have been mainly clarified： （1） chitosan can be an efficient sorbent for Cr （both Cr（Ⅲ） and Cr（Ⅵ））; （2） the effect of common ions on the adsorption ofCr （Cr（Ⅲ） and Cr（Ⅵ）） was not significant under this experimental conditions; （3） adsorption isotherms using the chitosan can be generally described by Langmuir isotherm more satisfactorily for Cr. The adsorption may have occurred mainly by monolayer reaction; （4） the rates of adsorption were found to conform to pseudo-second order kinetics.展开更多
This study investigated the adsorption ability of ZCHC （zeolite/chitosan hybrid composite） as adsorbent for chromium （Cr（Ⅵ））, ZCHC was prepared with sol-gel method by mixing zeolite and chitosan. Adsorption exp...This study investigated the adsorption ability of ZCHC （zeolite/chitosan hybrid composite） as adsorbent for chromium （Cr（Ⅵ））, ZCHC was prepared with sol-gel method by mixing zeolite and chitosan. Adsorption experiment from aqueous solutions containing known amount of Cr（Ⅵ） using zeolite, chitosan and ZCHC was explored to evaluate the efficiency of ZCHC as adsorbent for Cr in a batch system. The amount of Cr（Ⅵ） adsorbed at different pH values, initial concentrations, adsorbent dosages, and contact times were determined by ICP-AES （inductively coupled plasma-atomic emission spectrometry） in order to determine the optimum conditions for Cr（Ⅵ） adsorption. Furthermore, the adsorption mechanism of Cr（Ⅵ） by zeolite, chitosan and ZCHC was investigated by applying Langmuir and Freundlich isotherm equations to the data obtained. In addition, the rates of adsorption were found to conform to pseudo-second order kinetics.展开更多
The adsorption capacity of activated carbon modified with KMnO4(potassium permanganate)for Cr(VI)from aqueous solution was investigated.The modified activated carbon was characterized by SEM(scanning electron microsco...The adsorption capacity of activated carbon modified with KMnO4(potassium permanganate)for Cr(VI)from aqueous solution was investigated.The modified activated carbon was characterized by SEM(scanning electron microscopy),FT-IR(Fourier transform infrared spectrometer),and N2 adsorption/desorption tests.Adsorption of Cr(VI)from aqueous solution onto the activated carbon was investigated in a batch system.In the present study,the effect of various parameters such as pH,contact time and initial concentration on the adsorption capacity were determined by ICP-AES(inductively coupled plasma atomic emission spectrometry).The Cr(VI)adsorption on the activated carbon conforms to the Langmuir and Freundlich isothermal adsorption equation.The rates of adsorption were found to conform to pseudo-second order kinetic.The modified activated carbon can be an effective adsorbent for Cr(VI)from the aqueous solution.展开更多
文摘Adsorption experiment from aqueous solutions containing known amount of Cr （chromium） using chitosan was explored to evaluate the efficiency of chitosan as sorbent for Cr. Some variable parameters such as pH, reaction time and chitosan dosage were optimized. Under the optimum experiment condition, the effect of common ions on the adsorption of Cr （i.e., Na^＋, K^＋, Mg^2＋, Ca^2＋ for Cr（Ⅲ）, and Cl^-, NO3^-, SO4^2- for Cr（Ⅵ）） was also investigated. Furthermore, the sorption mechanism of Cr by chitosan was investigated by applying Langmuir and Freundlich isotherm equations to the data obtained. In addition, to confirm the characteristics of the chitosan, the surface morphology of the biomass was determined by SEM （scanning electron microscope） and specific surface area analyzer （N2-BET （Brunaeur, Emmet and Teller））. Consequently, the following matters have been mainly clarified： （1） chitosan can be an efficient sorbent for Cr （both Cr（Ⅲ） and Cr（Ⅵ））; （2） the effect of common ions on the adsorption ofCr （Cr（Ⅲ） and Cr（Ⅵ）） was not significant under this experimental conditions; （3） adsorption isotherms using the chitosan can be generally described by Langmuir isotherm more satisfactorily for Cr. The adsorption may have occurred mainly by monolayer reaction; （4） the rates of adsorption were found to conform to pseudo-second order kinetics.
文摘This study investigated the adsorption ability of ZCHC （zeolite/chitosan hybrid composite） as adsorbent for chromium （Cr（Ⅵ））, ZCHC was prepared with sol-gel method by mixing zeolite and chitosan. Adsorption experiment from aqueous solutions containing known amount of Cr（Ⅵ） using zeolite, chitosan and ZCHC was explored to evaluate the efficiency of ZCHC as adsorbent for Cr in a batch system. The amount of Cr（Ⅵ） adsorbed at different pH values, initial concentrations, adsorbent dosages, and contact times were determined by ICP-AES （inductively coupled plasma-atomic emission spectrometry） in order to determine the optimum conditions for Cr（Ⅵ） adsorption. Furthermore, the adsorption mechanism of Cr（Ⅵ） by zeolite, chitosan and ZCHC was investigated by applying Langmuir and Freundlich isotherm equations to the data obtained. In addition, the rates of adsorption were found to conform to pseudo-second order kinetics.
文摘The adsorption capacity of activated carbon modified with KMnO4(potassium permanganate)for Cr(VI)from aqueous solution was investigated.The modified activated carbon was characterized by SEM(scanning electron microscopy),FT-IR(Fourier transform infrared spectrometer),and N2 adsorption/desorption tests.Adsorption of Cr(VI)from aqueous solution onto the activated carbon was investigated in a batch system.In the present study,the effect of various parameters such as pH,contact time and initial concentration on the adsorption capacity were determined by ICP-AES(inductively coupled plasma atomic emission spectrometry).The Cr(VI)adsorption on the activated carbon conforms to the Langmuir and Freundlich isothermal adsorption equation.The rates of adsorption were found to conform to pseudo-second order kinetic.The modified activated carbon can be an effective adsorbent for Cr(VI)from the aqueous solution.
