title: Liquid Phase adsorption kinetics and equilibrium of toluene by novel modified-diatomite.
abstract: The adsorption equilibria of toluene from aqueous solutions on natural and modified diatomite were examined at different operation parameters such as pH, contact time, initial toluene concentration was evaluated and optimum experimental conditions were identified. The surface area and morphology of the nanoparticles were characterized by SEM, BET, XRD, FTIR and EDX analysis. It was found that in order to obtain the highest possible removal of toluene, the experiments can be carried out at pH 6, temperature 25°C, an agitation speed of 200 rpm, an initial toluene concentration of 150 mg/L, a centrifugal rate of 4000 rpm, adsorbent dosage = 0.1 g and a process time of 90 min. The results of this work show that the maximum percentage removal of toluene from aqueous solution in the optimum conditions for NONMD was 96.91% (145.36 mg/g). Furthermore, under same conditions, the maximum adsorption of natural diatomite was 71.45% (107.18 mg/g). Both adsorption kinetic and isotherm experiments were carried out. The experimental data showed that the adsorption follows the Langmuir model and Freundlich model on natural and modified diatomite respectively. The kinetics results were found to conform well to pseudo-second order kinetics model with good correlation. Thus, this study demonstrated that the modified diatomite could be used as potential adsorbent for removal of toluene from aqueous solution.
authors.affiliation: School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran.
authors.forename: Reza Khalighi
authors.initials: RK
authors.lastname: Sheshdeh
authors.affiliation: Department of Chemical Engineering, Tarbiat Modares University, Tehran, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Abbasizadeh
authors.affiliation: Ahwaz Faculty of Petroleum, Petroleum University of Technology (PUT), Ahwaz, Iran.
authors.forename: Mohammad Reza Khosravi
authors.initials: MR
authors.lastname: Nikou
authors.affiliation: Department of Environmental Researches, Institute for Color Science and Technology (ICST), Tehran, Iran.
authors.forename: Khashayar
authors.initials: K
authors.lastname: Badii
authors.affiliation: Ahwaz Faculty of Petroleum, Petroleum University of Technology (PUT), Ahwaz, Iran.
authors.forename: Mohammad Sadegh
authors.initials: MS
authors.lastname: Sharafi
keywords: Adsorption; Diatomite; Isotherm; Kinetics; Toluene