Studies on adsorption potential of oil-extracted marine macro algae Padina gymnospora for the removal of methylene blue

Abstract

The biosorption potential of Padina gymnospora for the methylene blue dye from the aqueous dye solution was studied. The effect of sorbent dosage, agitation, temperature, contact time and initial dye concentration on the uptake capacity of the biomass was studied in batch. The uptake capacity at equilibrium varied from 73.64 mg g−1 to 460.26 mg g−1 with increasing initial dye concentration of 20−100 mg L−1 for a biomass of 0.2 g. It was found that the biomass showed maximum adsorption capacity at 100 mg L−1 dye solution for a sorbent dosage of 0.2 g at 20°C with an agitation speed of 100 rpm. The equilibrium data was found to fit well with Freundlich isotherm and the reaction was found to follow the pseudo second order kinetics. The surface morphology of the biomass and the presence of various functional groups responsible for the adsorption were examined using SEM and FTIR.