Retention of Rifaximin from Aqueous Solution by Adsorption on PET Fibers

In this study, the adsorption of rifaximin (initial concentration 211 mg/L) from aqueous solution on PET fibers was analyzed. The influence of five experimental parameters (pH, fiber amount, initial concentration of antibiotic, contact time and temperature) on the adsorption efficiency was examined in batch systems. The best experimental conditions for the adsorption process were determined, and these are: pH = 2.0, 0.01 g PET fibers/25 mL of aqueous solution, a contact time of 3 hours, and ambient temperature (22 °C). Under these conditions, the maximum adsorption capacity is 14.08 mg/g. The isotherm modeling of the experimental data indicates that the adsorption of rifaximin on PET fibers is a multilayer process which occurs predominantly through physical interactions (according with the Freundlich models). These results highlight the potential applications of this adsorption process in both environmental engineering and medicine fields.