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 th...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.展开更多
研究了活性炭固定床对水中苯酚的动态吸附特性及影响因素。结果表明,活性炭对苯酚废水的动态吸附随进水苯酚含量和流量的增大穿透时间缩短,但最大设计体积流量不能超过6.47 m L/min;随固定床高度增加,穿透时间推迟,但最小设计高度不能小...研究了活性炭固定床对水中苯酚的动态吸附特性及影响因素。结果表明,活性炭对苯酚废水的动态吸附随进水苯酚含量和流量的增大穿透时间缩短,但最大设计体积流量不能超过6.47 m L/min;随固定床高度增加,穿透时间推迟,但最小设计高度不能小于8 cm。无效层厚度随进水流量和固定床高度的增加而增大,随进水苯酚含量增大而减少。经拟合发现实验结果更符合Yoon-Nelson模型,且相关系数都在0.9以上。展开更多
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)
文摘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.
文摘研究了活性炭固定床对水中苯酚的动态吸附特性及影响因素。结果表明,活性炭对苯酚废水的动态吸附随进水苯酚含量和流量的增大穿透时间缩短,但最大设计体积流量不能超过6.47 m L/min;随固定床高度增加,穿透时间推迟,但最小设计高度不能小于8 cm。无效层厚度随进水流量和固定床高度的增加而增大,随进水苯酚含量增大而减少。经拟合发现实验结果更符合Yoon-Nelson模型,且相关系数都在0.9以上。
