Abstract The adsorption rate of sodium dodecylbenzenesulfonate (SDBS) on three commercial activated carbons (ACs) and an AC synthesized from almond shells was investigated in this study. The mechanisms controlling the overall adsorption rate of SDBS on ACs were found out by using the pore volume and surface diffusion model (PVSDM). The PVSDM showed that the intraparticle diffusion of SDBS in all ACs was mainly attributed to pore volume diffusion and surface diffusion. The surface diffusion coefficient, Ds, in all samples of ACs are influenced by the amount of surfactant adsorbed at equilibrium, qe, as well as the mean micropore width, L0. The contribution of surface diffusion to the overall intraparticle diffusion ranged from 45 to 70%, depending on the properties of AC. Moreover, the branched-pore diffusional model was revisited (BPDMR) assuming that the Fick diffusion is the only diffusion mechanism in the macropores and the diffusion in the micropores was represented by the micropore rate coefficient, KC. Besides, it was proposed that the parameter f representing the mass fraction of SDBS adsorbed on macropores, can be estimated from the textural properties of ACs. Three new strategies were proposed to analyze the experimental data using BPDMR model, and it was demonstrated that the macropore diffusivity in BPDMR is close to the molecular diffusivity of SDBS in water solution. The micropore rate constant, KC, ranged from 3.90 × 10−6 to 10.6 × 10−6 s−1 and was affected by textural characteristics of ACs. Both models predicted the global adsorption rate of SDBS on ACs satisfactorily.

中文翻译：

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十二烷基苯磺酸钠在活性炭上的吸附动力学。重新审视分支孔扩散模型并与其他扩散模型进行比较

摘要 本研究研究了十二烷基苯磺酸钠 (SDBS) 在三种商用活性炭 (ACs) 和一种由杏仁壳合成的活性炭上的吸附率。通过使用孔体积和表面扩散模型（PVSDM）发现了控制 SDBS 在活性炭上的整体吸附速率的机制。PVSDM 表明 SDBS 在所有 ACs 中的粒子内扩散主要归因于孔体积扩散和表面扩散。所有活性炭样品中的表面扩散系数 Ds 受平衡时吸附的表面活性剂量 qe 以及平均微孔宽度 L0 的影响。表面扩散对整个颗粒内扩散的贡献范围为 45% 到 70%，具体取决于 AC 的特性。而且，重新审视分支孔扩散模型 (BPDMR)，假设 Fick 扩散是大孔中唯一的扩散机制，并且微孔中的扩散由微孔率系数 KC 表示。此外，有人提出参数 f 代表吸附在大孔上的 SDBS 的质量分数，可以从 ACs 的结构特性中估计出来。提出了三种新的策略来使用 BPDMR 模型分析实验数据，并证明 BPDMR 中的大孔扩散率接近于 SDBS 在水溶液中的分子扩散率。微孔率常数 KC 的范围为 3.90 × 10-6 至 10.6 × 10-6 s-1，并受 ACs 结构特征的影响。两种模型都令人满意地预测了 SDBS 在 AC 上的整体吸附率。