Removal of Sulfadimethoxine\nin Aqueous Solution by\nAdsorption on Mesoporous Carbon/Titania Composites: Batch Scale, Fixed-Bed\nColumn, and Bayesian Modeling

The antibiotic sulfadimethoxine (SMX) has been persistent\namong\nvarious pharmaceuticals in water sources. The purpose of this work\nis to investigate SMX removal through adsorption using four different\nmeso-carbonaceous materials or composites based on mesoporous carbon/titania\n(C-meso; C-meso/TiO<sub>2</sub>; CN-meso; CN-meso/TiO<sub>2</sub>).\nThe adsorption efficiency of the materials and the influence of the\nmain operational parameters, such as adsorbent dosage, contact time,\nand pH, were investigated. Moreover, a fixed-bed column process was\nalso conducted to simulate a continuous-flow scenario and evaluate\nthe material’s adsorbent performance under practical conditions,\nresulting in the best outcomes. Breakthrough curves obtained from\nthe column were assessed by the Monte Carlo Bayesian method, enhancing\nthe accuracy and robustness of the adsorption process model. Outcomes\nshow that the material with better results was C-meso/TiO<sub>2</sub>, achieving the maximum quantity of SMX adsorbed in equilibrium (<i>q</i><sub>e</sub>) of 50 mg<sub>SMX /</sub>g for 100% of\nSMX removed. Fixed-bed column outcomes show a broad range of maximum\nadsorption capacities (5.80 to 132.94 mg of SMX/g). Bayesian statistical\nmethods identified the Yan and log-Gompertz models as the most appropriate\nwith <i>R</i><sup>2</sup> values of 0.94 and 0.95, respectively.\nThe study demonstrated that C-meso/TiO<sub>2</sub> is a highly effective\nadsorbent for SMX removal in both batch and continuous systems. The\nresults highlight the critical role of optimizing operational parameters\nto maximize the adsorption efficiency. The Bayesian statistical approach\nprovided robust models for predicting breakthrough behaviors, which\nare essential for scaling up the process.