ADSORPTION KINETICS OF THE REMOVAL OF CIPROFLOXACIN FROM PHARMACEUTICAL WASTEWATER BY SURFACTANT MODIFIED KAOLINITEAbstract
In recent years, the extensive use of antibiotics has resulted in their frequent detection in the effluent discharge of wastewater discharge plants (WWTPs). In this study, the feasibility of using Surfactant-Modified Kaolinite (SMK) to remove the antibiotic, Ciprofloxacin (CIP) from wastewater was evaluated from batch experiments. The batch adsorption system was utilized to evaluate the CIP removal efficiency at different contact times, SMK dosages, and CIP concentrations. The experimental data were analyzed by the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich (D–R) isotherm models. R2 values of Langmuir and D–R isotherm models are higher than that of other models, and maximum monolayer coverage (qmax) was calculated as 61.82 mg/g. The separation factor of 0.495 indicated favorable sorption. Also, from the Freundlich isotherm model, the intensity of adsorption (n) that indicated favorable sorption was 2.954. The kinetic study of sorption indicates that the pseudo-second-order model provides a better correlation of the sorption data than the pseudo-first-order, confirming the chemisorption of CIP ions on SMK. The results showed that a significant increase in CIP sorption capacity could be achieved as the loading level of Cethyltrimethylammonium bromide (CTAB), a cationic surfactant, on kaolinite surface exceeds monolayer coverage.SMK shows promise to be an effective bio adsorbent for the removal of CIP from an aqueous solution. The adsorption involved is physisorption, which is best described by D-R isotherm.