J Environ Sci Health A Tox Hazard Subst Environ Eng 2021 Jan 27:1-17. Epub 2021 Jan 27.
Division of Sustainable Development, College of Science and Engineering, Hamad Bin Khalifa University, Education City, Doha, Qatar.
In the present study, the adsorption behavior of ciprofloxacin (CIP) from aqueous solution onto MWCNTs/AlO was studied using batch experiments. Physical characterization of MWCNTs/AlO was determined by SEM, XRD, and BET. The effective parameters investigated included: initial CIP concentration, contact time, MWCNTs/AlO mass, and temperature. Based on experimental results and correlation coefficients, the rate of CIP adsorption followed the pseudo-second-model kinetics. Complete compatibility of the adsorption isotherm process was achieved with the Langmuir model, and the maximum adsorption capacity reached 41.73 mg/g under the optimized conditions (pH = 7, MWCNTs/AlO dose = 1.2 g/L, contact time = 60 min, initial concentration = 10 mg/L, and temperature= 45 °C). The adsorption capacities based on the Langmuir model at different temperatures, 273, 288, 303, and 318 K, were equal to 72.18, 75.92, 79.65, and 83.47 mg/g, respectively. The determined parameters of the thermodynamic studies demonstrated the endothermic and spontaneous nature of the biosorption. The mean free energy was estimated from D-R isotherm model to be 0.316-0.707 KJ/mol, which clearly proved that the adsorption experiment followed a physical process. The data suggest that MWCNTs/AlO could be used as a highly effective adsorbent material with a high capacity for the removal of antibiotics from water and wastewater.