optimization and isothermal studies of antibiotics mixture biosorption from wastewater using palm kernel, chrysophyllum albidum, and coconut shells biocomposite

The presence of persistent pharmaceutical products in water bodies is a significant problem that obstructs wastewater reuse. this study investigated the adsorption process for removing the recalcitrant antibiotics, including tetracycline (tc), ampicillin (amp), and amoxicillin (amox) from an aqueous solution using a composite biosorbent made from a mixture of palm kernel shell (pks), chrysophyllum albidum (cas), and coconut shell (cs). simplex centroid design in the design of expert (12.0.1.0) was applied to optimize the percentage composition (20-55%) of the composite biosorbent precursor and to remove tc-amp amox mixtures from the aqueous solution in a batch study. the equilibrium data were fitted to 12 isotherm models and analyzed statistically. the maximum adsorption capacity of 9.12 mg/g, 8.66 mg/g, and 7.11 mg/g was achieved for tc, amp, and amox, respectively, using the biocomposite biosorbent with an optimal mixture of 55% pks, 20% cas, and 25% cs. the adsorption behavior of tc, amp, and amox was well-described by the langmuir/elovich isotherm (r2=1.000), hill-deboer (r2=0.9953), and freundlich/ halsey (r2=0.9898) models, respectively. the obtained results showed that the biocomposite pks-cas-cs leverages the individual adsorptive capacity of each constituent to enhance the adsorption process. moreover, the composite biosorbent demonstrated excellent potential for removing recalcitrant pharmaceuticals from wastewater effectively.