Authors: Xiao Qing Luo, Xiao Yan Lin, Xue Gang Luo, An Kai Luo, Xuan Liang
Abstract: This paper reports the feasibility of using rice husk to remove Ag+ from synthetic wastewater. Effect of various adsorption parameters, namely, pH, adsorbent dose, initial silver concentration and contact time has been studied in batch systems. The results indicated that rice husk offered high removal efficiency, fast adsorption rate and high uptake capacity for Ag+ ions. The equilibrium was attained within 20 min and the maximum removal efficiency at 11g/L rice husk and at pH 2 was found to be 99.76%. The kinetic data was fitted well to pseudo-second order model. The isotherm adsorption data was well described by the Langmuir isotherm model and the maximum uptake capacity of Ag+ ions onto rice husk was found to be 42.43 mg/g.
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Authors: Yi Nan Hao, Xi Ming Wang
Abstract: Xanthoceras Sorbifolia Bunge crust was used as source material to make carbon by chemically impregnated by sodium hydroxide、carbonized at 220°C and activated under the protection of the nitrogen. Experiments were carried out as function of contact time, pH (4-10) and temperature (293,303 and 313K). Adsorption isotherms were modeled with the Langmuir and Freundlich isotherms. Adsorption isotherms of Basic Fuchsin on Xanthoceras Sorbifolia Bunge crust activated carbon are consistent with Langmuir equation. The Langmuir monolayer saturation capacities of BF adsorbed onto activated carbon were 286.545, 303.617 and 323.816 mg/g at 293,303, and 313 K, respectively.and adsorption kinetics were found to conform to the pseudo-second-order kinetics with good correlation.Using the equilibrium concentration contents obtained at different temperatures, various thermodynamic parameters,such as △G,△H and △S, have been calculated. The thermodynamics parameters of system indicated spontaneous and endothermic process.
272
Authors: Xue Yi Guo, Sha Liang, Qing Hua Tian
Abstract: In this study, orange peel (OP) was modified by KCl to prepare a novel orange peel adsorbent named as KOP. The adsorption behaviors of KOP for five heavy metals (Cu2+, Cd2+, Pb2+, Zn2+, Ni2+) were studied. The effects of pH, adsorption time and metal ion concentration on single heavy metal solution adsorption by KOP were investigated. All adsorption processes can attain equilibrium with 20min and kinetics data of five heavy metal ions were fitted to pseudo-second-equation; the maximum adsorption capacities for Cu2+, Cd2+, Pb2+, Zn2+ and Ni2+ were calculated as 59.77, 125.63, 141.84, 45.29 and 49.14 mg/g, respectively. Recycle and reuse experiments indicate that KOP could be used for more than 10 cycles. The effect of coexist metal ions on adsorption can be neglected.
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Authors: Yi Nan Hao, Xi Ming Wang, Li Jun Ding, Da Yan Ma
Abstract: Xanthoceras Sorbifolia Bunge hull activated carbon (XSBHAC) developed by phosphoric acid activation for removing basic fuchsin (BF) has been investigated. Experiments were carried out as function of contact time, pH (4-10) and temperature (303,313 and 323K). Adsorption isotherms were modeled with the Langmuir and Freundlich isotherms. The data fitted well with the Langmuir isotherm. The Langmuir monolayer saturation capacities of BF adsorbed onto activated carbon were 351.35, 354.96 and 355.94 mg/g at 303,313, and 323 K, respectively.The kinetic models were also studied .The rates of adsorption were found to conform to the pseudo-second-order kinetics with good correlation.Using the equilibrium concentration contents obtained at different temperatures, various thermodynamic parameters,such as △G,△H and △S, have been calculated. The thermodynamics parameters of system indicated spontaneous and endothermic process. Key words: Xanthoceras sorbifolia bunge hull;biosorption; basic fuchsin
486
Authors: Ming Xia Fan, Kun Wang, Ya Zhou Wang, Dan Qing Yu
Abstract: In the present investigation, lab-made mesoporous activated carbon (MAC) was prepared for testing the ability to remove Cr(VI) from aqueous solution. The influences of several operating parameters such as pH and temperature on the adsorption were investigated. Solution pH is found highly influencing the adsorption and low pH is favorable for Cr(VI) adsorption. The adsorption of Cr(VI) is enhanced with increased temperature. Thermodynamic parameters were evaluated and the adsorption was endothermic. Several adsorption isotherms include Langmuir, Freundlich and Dubinin–Radushkevich(D–R) were used to fit the equilibrium data. The adsorption kinetic data of Cr(VI) were analyzed and was found fitting well in pseudo-second order equation. The lab-made MAC is found to be effective adsorbent for removal of Cr(VI) from aqueous solutions.
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