机构地区:[1]School of Chemical and Environment Engineering, Wuyi University [2]School of Chemistry and Chemical Engineering, South China University of Technology
出 处:《Journal of Wuhan University of Technology(Materials Science)》2014年第6期1152-1160,共9页武汉理工大学学报(材料科学英文版)
基 金:Funded by the Research Fund of the Guangdong Provincial Laboratory of Green Chemical Product Technology(China);the Science Foundation for Young Teachers of Wuyi University(No.2013zk11)
摘 要:P-nitrophenol(PNP) adsorption in batch and fixed bed adsorbers was studied. The homogeneous surface diffusion model(HSDM) based on external mass transfer and intraparticle surface diffusion was used to describe the adsorption kinetics for PNP in stirred batch adsorber at various initial concentrations and activated carbon dosages. The fixed bed model considering both external and internal mass transfer resistances as well as axial dispersion with non-linear isotherm was utilized to predict the fixed bed breakthrough curves for PNP adsorption under the conditions of different flow rates and inlet concentrations. The equilibrium parameters and surface diffusivity(Ds) were obtained from separate experiments in batch adsorber. The obtained value of Ds is 4.187×1012 m2/s. The external film mass transfer coefficient(kf) and axial dispersion coefficient(DL) were estimated by the correlations of Goeuret and Wike-Chang. The Biot number determined by HSDM indicated that the adsorption rate of PNP onto activated carbon in stirred batch was controlled by intraparticle diffusion and film mass transfer. A sensitivity analysis was carried out and showed that the fixed bed model calculations were sensitive to Ds and kf, but insensitive to DL. The sensitivity analysis and Biot number both confirm that intraparticle diffusion and film mass transfer are the controlling mass transfer mechanism in fixed bed adsorption system.P-nitrophenol(PNP) adsorption in batch and fixed bed adsorbers was studied. The homogeneous surface diffusion model(HSDM) based on external mass transfer and intraparticle surface diffusion was used to describe the adsorption kinetics for PNP in stirred batch adsorber at various initial concentrations and activated carbon dosages. The fixed bed model considering both external and internal mass transfer resistances as well as axial dispersion with non-linear isotherm was utilized to predict the fixed bed breakthrough curves for PNP adsorption under the conditions of different flow rates and inlet concentrations. The equilibrium parameters and surface diffusivity(Ds) were obtained from separate experiments in batch adsorber. The obtained value of Ds is 4.187×1012 m2/s. The external film mass transfer coefficient(kf) and axial dispersion coefficient(DL) were estimated by the correlations of Goeuret and Wike-Chang. The Biot number determined by HSDM indicated that the adsorption rate of PNP onto activated carbon in stirred batch was controlled by intraparticle diffusion and film mass transfer. A sensitivity analysis was carried out and showed that the fixed bed model calculations were sensitive to Ds and kf, but insensitive to DL. The sensitivity analysis and Biot number both confirm that intraparticle diffusion and film mass transfer are the controlling mass transfer mechanism in fixed bed adsorption system.
关 键 词:adsorption activated carbon modeling fixed bed adsorber simulation
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