Methylene Blue Adsorption onto Coconut husks/Polylactide Blended Films: Equilibrium and Kinetic Studies

Abstract

The removal of cationic methylene blue (MB) from aqueous solutions by coconut husks/polylactide blended films was studied in a batch system. Experiments were modeled as a function of contact time, initial dye concentration, ionic strength, adsorbent dose, temperature and initial solution p^H. Equilibrium data fitted the Langmuir isotherm model (R²>0.9866) with monolayer adsorption capacity q_m = 16.34mg/g at 296K. Adsorption kinetics followed the pseudo-second model (R²>0.9997) hence chemisorption rate limiting step was dominant. The results have shown viability of coconut husks/polylactide blended films for the removal of recalcitrant MB from both domestic and industrial wastewaters.

Key words: coconut husks, polylactide, methylene blue, isotherm, kinetics