title: Citric acid modified kenaf core fibres for removal of methylene blue from aqueous solution.
abstract: Chemically modified kenaf core fibres were prepared via esterification in the presence of citric acid (CA). The adsorption kinetics and isotherm studies were carried out under different conditions to examine the adsorption efficiency of CA-treated kenaf core fibres towards methylene blue (MB). The adsorption capacity of the kenaf core fibres increased significantly after the citric acid treatment. The values of the correlation coefficients indicated that the Langmuir isotherm fitted the experimental data better than the Freundlich isotherm. The maximum adsorption capacity of the CA-treated kenaf core fibres was found to be 131.6mg/g at 60°C. Kinetic models, pseudo-first-order, pseudo-second-order and intraparticle diffusion, were employed to describe the adsorption mechanism. The kinetic data were found to fit pseudo-second-order model equation as compared to pseudo-first-order model. The adsorption of MB onto the CA-treated kenaf core fibres was spontaneous and endothermic.
authors.affiliation: School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia.
authors.forename: Mohd Shaiful
authors.initials: MS
authors.lastname: Sajab
authors.forename: Chin Hua
authors.initials: CH
authors.lastname: Chia
authors.forename: Sarani
authors.initials: S
authors.lastname: Zakaria
authors.forename: Saad Mohd
authors.initials: SM
authors.lastname: Jani
authors.forename: Mohd Khan
authors.initials: MK
authors.lastname: Ayob
authors.forename: Kah Leong
authors.initials: KL
authors.lastname: Chee
authors.forename: Poi Sim
authors.initials: PS
authors.lastname: Khiew
authors.forename: Wee Siong
authors.initials: WS
authors.lastname: Chiu
mesh_terms: D000327:Adsorption; D001673:Biodegradation, Environmental; D019343:Citric Acid / Q000737:chemistry*; D031584:Hibiscus / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008751:Methylene Blue / Q000302:isolation & purification*; D008956:Models, Chemical; D012996:Solutions; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D012996:Solutions; D014874:Water Pollutants, Chemical; D019343:Citric Acid; D008751:Methylene Blue