This work investigates the effect of adsorbent geometry on diffusion mechanisms assuming form factors as a new approach in the conception of mass transfer model. Experimental nickel adsorption on activated carbon and sugarcane bagasse were selected as case studies. According to SEM images, the activated carbon geometry can be approximated as a sphere with sphericity of 0.47, while the sugarcane bagasse geometry was considered an infinite cylinder. In both cases, the equilibrium data were suitable elucidated by Sips isotherm and the thermodynamic parameters revealed exothermic and spontaneous adsorption process. The numerical solution of the diffusional model was developed and presented in detail considering the geometry of each case study. Finite difference approximations and nonlinear least squares methods have been successfully used to estimate and predict the dynamic adsorption behavior in terms of mass transfer phenomena. It was observed that the adsorption rate was influenced by the geometry and textural characteristics of the adsorbents. Both surface diffusion (70%) and pore volume diffusion (30%) presented a significant contribution in the activated carbon adsorption. However, only surface diffusion (97%) was significant in the sugarcane bagasse adsorption, since its porosity is three times lower than activated carbon.

这项工作研究吸附剂的几何形状对扩散机理的影响，假设形式因素是传质模型概念中的一种新方法。案例研究选择了在活性炭和甘蔗渣上的镍吸附实验。根据SEM图像，活性炭的几何形状可以近似为球形度为0.47的球体，而甘蔗渣的几何形状则被认为是无限圆柱体。在两种情况下，均可以通过Sips等温线阐明平衡数据，并且热力学参数显示出放热和自发吸附过程。考虑到每个案例研究的几何形状，开发并详细介绍了扩散模型的数值解。有限差分近似和非线性最小二乘法已成功地用于根据传质现象估算和预测动态吸附行为。观察到吸附速率受吸附剂的几何形状和结构特征的影响。表面扩散（70％）和孔体积扩散（30％）都对活性炭的吸附有重要贡献。然而，由于甘蔗渣的孔隙率比活性炭低三倍，因此在甘蔗渣吸附中仅表面扩散（97％）很明显。表面扩散（70％）和孔体积扩散（30％）都对活性炭的吸附有重要贡献。然而，由于甘蔗渣的孔隙率比活性炭低三倍，因此在甘蔗渣吸附中仅表面扩散（97％）很明显。表面扩散（70％）和孔体积扩散（30％）都对活性炭的吸附有重要贡献。然而，由于甘蔗渣的孔隙率比活性炭低三倍，因此在甘蔗渣吸附中仅表面扩散（97％）很明显。