Desorption of chloramphenicol from ordered mesoporous carbon-alginate beads: Effects of operating parameters, and isotherm, kinetics, and regeneration studies

Abstract

This study has investigated the desorption of an emerging contaminant, known as chloramphenicol (CPC), from ordered mesoporous carbon (OMC)-alginate beads. The effects of initial concentration, operating temperature, and a selection of eluents (water, ethanol, and sodium chloride (NaCl)) on the whole desorption process were analysed. The desorption efficiency was found to decrease with increasing temperature, an indication for a favourable desorption process at a lower temperature range. NaCl was the most effective eluent for the CPC desorption process, followed by ethanol and water. The use of 1 M NaCl has resulted in the highest desorption efficiency of 84.7%. Redlich-Peterson and Freundlich isotherm models fitted well to the CPC desorption experimental data. The desorption kinetic data for ethanol and NaCl as eluents fitted well to the pseudo-second order kinetic model. Meanwhile, distilled water as an eluent was best fitted to the pseudo-first order kinetic model. The CPC adsorption efficiency began to notably decrease from 78.9% to 48.5% after five consecutive adsorption/desorption cycles. Similarly, the desorption efficiency began to decrease from 76.0% in the first cycle down to 35.2% in the fifth cycle. These findings demonstrated that the OMC-alginate beads are a very promising adsorbent with excellent desorption and reusability characteristics towards the targeted antibiotic, CPC.