Application of Nanocrystalline Iranian Diatomite in Immobilized Form for Removal of a Textile Dye. Issue 5 (3rd May 2016)

• Record Type: Journal Article
• Authors: Darvishi Cheshmeh Soltani, Reza; Safari, Mahdi; Maleki, Afshin; Godini, Hatam; Mahmoudian, Mohammad Hassan; Pordel, Mohammad Amin
• Is Part Of: Journal of dispersion science and technology. Volume 37:Issue 5(2016)
• Page Start: 723
• Page End: 732
• Publication Date: 2016-05-03
• Subjects: Adsorption -- azo dye -- immobilization -- nanobiocomposite -- nanostructured diatomite; Emulsions -- Periodicals; Suspensions (Chemistry) -- Periodicals; Emulsions; Suspensions; 541.34
• DOI: 10.1080/01932691.2015.1058715
• Languages: English
• ISSNs: 0193-2691

Abstract

Abstract : The aim of the present investigation was to immobilize nanocrystalline diatomite within calcium alginate matrix for the adsorption of Direct Red23 (DR23) in aqueous media. Scanning electron microscopy (SEM), x-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy were used to characterize the samples. As a result, the adsorption process obeyed pseudo - second-order kinetic model ( R 2 = 0.9934) and Langmuir isotherm model ( R 2 = 0.9732) with a maximum adsorption capacity of 24.10 mg/g. The value of mean free energy (15.81 kJ/mol) demonstrated that the process has been taken place chemically. As the adsorbent dosage increased from 0.5 to 3.0 g/L, the decolorization efficiency (%) increased from 26.0 to 75.5%, respectively. Inversely, the decolorization efficiency (%) decreased from 98.0 to 29.0% with increasing initial dye concentration from 5 to 160 mg/L, respectively. The negative values obtained for Gibbs free energy ( ΔG° ) and positive value of enthalpy change ( ΔH° ) indicated spontaneous and endothermic nature of the process. GRAPHICAL ABSTRACT: