The efficacy of ciprofloxacin removal by Chitosan/Zeolite composite from aqueous solution:Response surface methodology, kinetic and isotherm studies

Antibiotics are potential pollutants that their disposal and release into the environment and especially aqueous solutions may result in serious problems. Owing to the high toxicity and low biodegradability of these compounds, their residuals mayhave adverse effects on human health and other organisms. In this study, the removal of ciprofloxacin by chitosan composite/zeolite was investigated.
The effect of various parameters including initial concentration of antibiotic, solution pH, adsorbent dosage, and contact time on the process was studied.The design expert software and response surface methodology were used to investigate the effects of operating variables and optimization conditions. Kinetic and adsorption isotherm studies were done and physical and structural features were determined using SEM, FT-IR and pHpzc. In carrying out this study and the use of resources, ethical issues were all considered.
The maximum removal efficacy of ciprofloxacin (97.5%) was at initial concentration 5mg/L, pH 7, adsorbent dosage2 g/L, and contact time 37.5 min. The initial concentration of ciprofloxacin and adsorbent dosage were most effective parameters on the removal efficiency. Adsorption isotherm studies revealed that the experimental data best fitted to the Langmuir isotherm model (R2=0.9995). Kinetic studies identified second order model as a suitable model for description of adsorption process(R2= 9973).
The present study showed that the adsorption process by chitosan / zeolite composite as a suitable adsorbent can be a cost effective and good alternative to remove antibiotics from aqueous solutions.