Sonetaka Noriyoshi, Fan Huan-Jung, Kobayashi Seiji, Su Yang-Chih, Furuya Eiji
Network Service Division, NEC Corporation, Tokyo, Japan.
J Hazard Mater. 2009 Jun 15;165(1-3):232-9. doi: 10.1016/j.jhazmat.2008.09.111. Epub 2008 Oct 7.
In general, the adsorption uptake curve (AUC) can be easily determined in either intraparticle diffusion or liquid film mass transfer dominating systems. However, for both intraparticle diffusion and liquid film mass transfer controlling systems, the characterization of AUC is much more complicated, for example, when relatively small adsorbent particles are employed. In addition, there is no analytical solution available for both intraparticle diffusion and liquid film mass transfer controlling systems. Therefore, this paper is trying to characterize AUC for both intraparticle diffusion and liquid film mass transfer controlling adsorption systems using the shallow bed reactor technique. Typical parameters influencing AUC include liquid film mass transfer coefficient (k(F)), effective intraparticle diffusivity (D(S)), influent concentration (c(0)) and equilibrium parameters (such as Freundlich isotherm constants k and 1/n). These parameters were investigated in this research and the simulated results indicated that the ratio of k(F)/D(S) and Freundlich constant 1/n had impact on AUC. Biot number (Bi) was used to replace the ratio of k(F)/D(S) in this study. Bi represents the ratio of the rate of transport across the liquid layer to the rate of intraparticle diffusion. Furthermore, Bi is much more significant than that of 1/n for AUC. Therefore, AUC can be characterized by Bi. In addition, the obtained Bi could be used to determine D(S) and k(F) simultaneously. Both parameters (D(S) and k(F)) are important for designing and operating fixed bed reactors.
一般来说，在颗粒内扩散或液膜传质主导的系统中，吸附吸收曲线（AUC）很容易确定。然而，对于颗粒内扩散和液膜传质控制的系统，AUC的表征要复杂得多，例如，当使用相对较小的吸附剂颗粒时。此外，对于颗粒内扩散和液膜传质控制的系统，没有可用的解析解。因此，本文试图使用浅床反应器技术来表征颗粒内扩散和液膜传质控制的吸附系统的AUC。影响AUC的典型参数包括液膜传质系数（k(F)）、颗粒内有效扩散系数（D(S)）、进水浓度（c(0)）和平衡参数（如弗伦德利希等温线常数k和1/n）。本研究对这些参数进行了研究，模拟结果表明k(F)/D(S)的比值和弗伦德利希常数1/n对AUC有影响。在本研究中，用毕奥数（Bi）来代替k(F)/D(S)的比值。Bi表示穿过液层的传输速率与颗粒内扩散速率的比值。此外，对于AUC，Bi比1/n更显著。因此，AUC可以用Bi来表征。此外，得到的Bi可用于同时确定D(S)和k(F)。这两个参数（D(S)和k(F)）对于固定床反应器的设计和运行都很重要。
