Optimization of Simultaneous Removal of Binary Toxic Antibiotic and Heavy Metal by Novel Biocomposite Beads: Modeling Study Using Brouers–Sotolongo Family Equations

Antibiotics and heavy metals have been widely used in the livestock industry as feed additives in order to promote animal health and growth performance through antimicrobial activity mechanisms. These toxic pollutants should be removed to promote the environment. In this work, biocomposite beads based on lignocellulosic materials (reed plant) were synthesized for simultaneous removal of oxytetracycline (OTC) and cadmium Cd(II), antibiotic and the heavy metal, respectively, from aqueous solution. The biosorbent was characterized by FTIR-ATR, SEM, TGA analysis, and by determining its isoelectric point. The optimization of such independent variables as adsorbent mass, initial OTC concentration, initial Cd(II) concentration, contact time, and pH affecting binary antibiotic and the heavy metal removal was developed by central composite design under response surface methodology (CCD-RSM). The kinetics data showed that the biosorption of OTC and Cd(II) follows the Weibull model. The Jovanovich and Freundlich models seemed more adequate for OTC biosorption, although the biosorption of Cd(II) follows the Brouers–Gaspard (BG) isotherm model.