title: Biosorption of nickel(II) ions onto Sargassum wightii: application of two-parameter and three-parameter isotherm models.
abstract: Biosorption of nickel(II) ions from aqueous solution onto Sargassum wightii has been studied and the equilibrium isotherms were determined. The experimental data obtained at different pH conditions (pH 3.0-4.5) have been analyzed using five two-parameter models (Langmuir, Freundlich, Temkin, Dubinin-Radushkevich and Flory-Huggins) and five three-parameter models (Redlich-Peterson, Sips, Khan, Radke-Prausnitz and Toth). In order to determine the best fit isotherm, three error analysis methods were used to evaluate the data: correlation coefficient, residual root mean square error and chi-square test. The error analysis demonstrated that the three-parameter models better described the nickel biosorption data compared to two-parameter models. In particular, Toth equation provided the best model for nickel biosorption data at all pH conditions examined.
authors.affiliation: Department of Chemical Engineering, Anna University, Chennai, India.
authors.forename: K
authors.initials: K
authors.lastname: Vijayaraghavan
authors.forename: T V N
authors.initials: TV
authors.lastname: Padmesh
authors.forename: K
authors.initials: K
authors.lastname: Palanivelu
authors.forename: M
authors.initials: M
authors.lastname: Velan
mesh_terms: D000327:Adsorption; D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000737:chemistry; D008954:Models, Biological; D008956:Models, Chemical; D009532:Nickel / Q000737:chemistry* / Q000378:metabolism*; D044647:Sargassum / Q000378:metabolism*
chemical_list: D007477:Ions; D009532:Nickel