title: Adsorption of sunset yellow FCF from aqueous solution by chitosan-modified diatomite.
abstract: Sunset yellow (SY) FCF is a hazardous azo dye pollutant found in food processing effluent. This study investigates the use of diatomaceous earth with chitosan (DE@C) as a modified adsorbent for the removal of SY from wastewater. Fourier transform infrared spectroscopy results indicate the importance of functional groups during the adsorption of SY. The obtained N2 adsorption-desorption isotherm values accord well with IUPAC type II. Our calculations determined a surface area of 69.68 m2 g(-1) for DE@C and an average pore diameter of 4.85 nm. Using response surface methodology, optimized conditions of process variables for dye adsorption were achieved. For the adsorption of SY onto DE@C, this study establishes mathematical models for the optimization of pH, contact time and initial dye concentration. Contact time plays a greater role in the adsorption process than either pH or initial dye concentration. According to the adjusted correlation coefficient (adj-R2>0.97), the models used here are suitable for illustration of the adsorption process. Theoretical experimental conditions included a pH of 2.40, initial dye concentration of 113 mg L(-1) and 30.37 minutes of contact time. Experimental values for the adsorption rate (92.54%) were close to the values predicted by the models (95.29%).
authors.affiliation: The College of Architecture and Civil Engineering, The Key Laboratory of Beijing for Water Quality Science & Water Environment Recovery Engineering, Beijing University of Technology, Beijing, 100124, China E-mail: lijunbjut@163.com.
authors.forename: Y Z
authors.initials: YZ
authors.lastname: Zhang
authors.affiliation: The College of Architecture and Civil Engineering, The Key Laboratory of Beijing for Water Quality Science & Water Environment Recovery Engineering, Beijing University of Technology, Beijing, 100124, China E-mail: lijunbjut@163.com.
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.affiliation: The College of Architecture and Civil Engineering, The Key Laboratory of Beijing for Water Quality Science & Water Environment Recovery Engineering, Beijing University of Technology, Beijing, 100124, China E-mail: lijunbjut@163.com.
authors.forename: W J
authors.initials: WJ
authors.lastname: Li
authors.affiliation: The College of Architecture and Civil Engineering, The Key Laboratory of Beijing for Water Quality Science & Water Environment Recovery Engineering, Beijing University of Technology, Beijing, 100124, China E-mail: lijunbjut@163.com.
authors.forename: Y
authors.initials: Y
authors.lastname: Li
mesh_terms: D000327:Adsorption; D001391:Azo Compounds / Q000737:chemistry / Q000302:isolation & purification*; D048271:Chitosan / Q000737:chemistry / Q000302:isolation & purification; D004396:Coloring Agents / Q000737:chemistry; D007692:Diatomaceous Earth / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008962:Models, Theoretical; D017550:Spectroscopy, Fourier Transform Infrared; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D001391:Azo Compounds; D048271:Chitosan; D004396:Coloring Agents; D007692:Diatomaceous Earth; D062065:Wastewater; D014874:Water Pollutants, Chemical; C033787:diatomite; C005842:6-hydroxy-5-((p- sulfophenyl)azo)-2-naphthalenesulfonic acid disodium salt