Studies on Adsorption Kinetics of Norfloxacin Using Nano Alumina in Aqueous Medium

The adsorption of norfloxacin at Nano Alumina was studied at different experimental conditions such as contact time, pH, concentration of norfloxacin, and the amount of adsorbent for adsorption efficiency. The average particle size of 13 nm was investigated by using XRD. Adsorption kinetics and the Langmuir, Freundlich, Tempkin models were applied to describe the equilibrium isotherms, and the isotherm constants were determined. The optimum values of adsorbent dosage, contact time, initial norfloxacin concentration, and pH were evaluated as 50 mg, 10 min, 1.66 gL-1, and 2.5, respectively. Langmuir isotherm is shown maximum adsorption capacity (Q0) is 0.0347 mol/g. Different kinetic models were also studied and pseudo-first-order was well fitted with experiment. A good removal efficiency of 82.5 % was observed. The adsorption mechanism was explored using the intra-particle diffusion model. The adsorption was studied thermodynamically, and the Gibbs free energy change (ΔG0), enthalpy change (ΔH0), and entropy (ΔS0), were calculated. Negative values of ΔG0 at different temperatures pointed towards the spontaneity of the adsorption of norfloxacin by Nano alumina from aqueous solution.