Promotion of clinoptilolite adsorption for azithromycin antibiotic by Tween 80 and Triton X-100 surface modifiers under batch and fixed-bed processes

Abstract

In this study, azithromycin (AZT) adsorbed on natural clinoptilolite (NC) modified by Triton X-100 (NC-Triton) and Tween 80 (NC-Tween) surfactants. The effect of pH, contact time, adsorbent dose, and temperature on the adsorption was investigated. For NC, the Temkin isotherm and for NC-Tween and NC-Triton, Langmuir isotherm fitted the experimental data well. The maximum adsorption capacity value of NC, NC-Tween, and NC-Triton was 28.011, 36.764, and 44.642 mg/g, respectively. Fixed-bed experiments were performed under different conditions to predict breakthrough curve. For NC and NC-Tween, the intra-particle diffusion kinetic model and for NC-Triton, fractional power model were the best investigated models. The thermodynamic parameters of Gibbs free energy for NC, for NC-Tween, for NC-Triton in 20-35 °C, enthalpy and entropy changes for NC, and for NC-Tween, and for NC-Triton were determined.