Batch Studies on Biosorption of Ciprofloxacin on Freshwater Macro Alga Lemna minor

Objectives: Ciprofloxacin (CIP) antibiotic adsorption from aqueous solution unto Lemna minor (LM) was studied. The aim of the experiment was to utilize the LM as a cheap alternative adsorbent compared to more expensive and relatively less effective techniques for the removal of CIP from solution. Methods: The experiment was performed using batch adsorption technique. Thermodynamic parameters such as the changes in enthalpy, entropy and Gibbs free energy was determined, showing adsorption to be an endothermic yet spontaneous process. Pseudo-first-order, pseudo-second- order and intraparticle diffusion models were considered to evaluate the rate parameters. Results: The experimental data fitted the pseudo-second- order kinetic model, with qe between 4.31 to 19.62 mg/g at concentrations between 10 to 50 mg/L. also due to the inter-particle diffusion, It can be stated that mechanism of the adsorption process is probably a combination of boundary layer and pore diffusion which contribute to the rate determining step. Conclusion: The results indicate that LM biomass could be employed as a low-cost in wastewater treatment for the removal of antibiotics.