Removal of methylene blue from aqueous solution using alkali-modified malted sorghum mash

Authors : Emmanuel Olajide OYELUDE, Felix APPIAHTAKYI

Pages : 161-169

Doi:10.3906/sag-1205-17

View : 17 | Download : 9

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :The removal of methylene blue insert ignore into journalissuearticles values(MB); from aqueous solution by NaOH-modified malted sorghum mash insert ignore into journalissuearticles values(NSM); at different contact times, initial solution pH, adsorbent dose, temperature, and initial dye concentration was investigated. The adsorption of MB by NSM increased with increasing contact time and the process attained equilibrium within 18 min. The extent of dye removal decreased with increasing adsorbent dosage but increased with increase in temperature. The adsorption isotherm was found to follow the Langmuir model. The maximum monolayer adsorption capacity obtained was 357.1 mg/g at 306 K. The estimated adsorption free energy insert ignore into journalissuearticles values(D G°);, enthalpy change insert ignore into journalissuearticles values(D H°);, and entropy change insert ignore into journalissuearticles values(D S°); for the adsorption process were --20.85 kJ/mol, 38.31 kJ/mol, and 68.16 J/mol K, respectively, at 306 K. The adsorption process was feasible, endothermic, and spontaneous. The low value of D G° suggests a physical adsorption process, while the positive value of D S° reflects the affinity of NSM for MB.
Keywords : Adsorption, methylene blue, malted sorghum mash, Langmuir isotherm