Removal of Lambda-Cyhalothrin from Aqueous Solution Using Algae – Kinetic, Isotherm and Thermodynamic Studies

Abstract

The present study aims to determine the ability of algae in sequestering Lambda‐cyhalothrin (L-C) from aqueous solution. A series of experiments were carried out in batch mode to find equilibrium data for sorption of Lambda‐cyhalothrin (L-C), FTIR analysis was utilized to investigate the impacts of functional groups of algae in the biosorption process. Pseudo second-order kinetics model (R2=0.991) well describe the kinetics of adsorption of L-C onto algae sites while the adsorption mechanisms was controlled by external mass transfer as well as intraparticle diffusion. Langmuir isotherm model better fit the experimental data than Freundlich isotherm model. The higher adsorption capacity was found to be 6.954mg/g. Thermodynamic parameters indicating that sorption of L-C onto algae was endothermic in nature. Only 40% reduction in the sequestration efficiency was noticed after five sequential regeneration cycles. The maximum sorption efficiency was found to be (95.6%) under the best conditions adsorbent dosage=1g/100ml, pH=7, initial L-C concentration=10 mg/l with a contact time of 60 minutes at 25°C. This work demonstrated that algae are a promising adsorbent for L-C removal from aqueous solution.

Keywords

• adsorption
• algae
• kinetics
• lambda-cyhalothrin
• regeneration