Chemical Engineering, Faculty of Chemical Sciences, University of Cuenca, 010203, Cuenca, Ecuador.
Center for Environmental Studies, Department of Applied Chemistry and Production Systems, Faculty of Chemical Sciences, University of Cuenca, 010203, Cuenca, Ecuador.
Chemosphere. 2021 Oct;280:130687. doi: 10.1016/j.chemosphere.2021.130687. Epub 2021 Apr 27.
Having rigorous mathematical models is essential for the design and scaling of adsorption columns. In this study, the dynamic behavior of the sulfamethoxazole adsorption on sugarcane bagasse was studied and compared using analytical models and a theoretical mechanistic model. Initially, fixed-bed column tests were carried out at different flow rates and bed heights. Then, the experimental data were fitted with the most widely used analytical kinetic models, and their fit and fixed-bed parameters were compared with the mechanistic model. Of all analytical models analyzed, the Log-Gompertz model was the one that had the best agreed with experimental data. Although some analytical models fitted the experimental data accurately, their usefulness was questionable. Their parameters did not show a clear relationship with the change in operating conditions, and in certain cases had different behavior from that observed in experimentation. Conversely, the mechanistic model not only predicted the breakthrough curves with great accuracy in the initial and transition stage (R > 0.92; SSE < 0.06), but it also estimated relevant parameters. Additionally, the effects of the global mass transfer coefficient (K) and the axial dispersion coefficient (D) on breakthrough curves were studied using the mechanistic model. Increasing K increased the slope of the breakthrough curves with a faster adsorption rate. Similarly, high values of D produced lower adsorption capacities of the adsorbent; and it was established that the axial dispersion is relevant in SMX adsorption on SB. The theoretical model presented can be used for the design, scaling, and optimization of adsorption columns.
拥有严格的数学模型对于吸附柱的设计和缩放至关重要。在这项研究中，使用分析模型和理论机理模型研究和比较了磺胺甲恶唑在甘蔗渣上的动态吸附行为。首先，在不同的流速和床层高度下进行了固定床柱试验。然后，将实验数据拟合最广泛使用的分析动力学模型，并将其拟合和固定床参数与机理模型进行比较。在所分析的所有分析模型中，对数戈默特定律模型与实验数据的吻合度最好。尽管某些分析模型准确地拟合了实验数据，但它们的有用性值得怀疑。它们的参数没有显示出与操作条件变化的明显关系，并且在某些情况下与实验观察到的行为不同。相反，机理模型不仅在初始和过渡阶段（R>0.92；SSE<0.06）非常准确地预测了突破曲线，而且还估计了相关参数。此外，使用机理模型研究了全局传质系数（K）和轴向扩散系数（D）对突破曲线的影响。增加 K 会增加突破曲线的斜率，从而提高吸附速率。同样，高 D 值会导致吸附剂的吸附容量降低；并且确定轴向扩散在 SB 上的 SMX 吸附中是相关的。所提出的理论模型可用于吸附柱的设计、缩放和优化。
