Modification of magadiite surface by organofunctionalization for application in removing As(V) from aqueous media: Kinetic and thermodynamic

• Published in: Applied surface science Vol. 256; no. 3; pp. 702 - 709
• Main Authors: GUERRA, Denis L, PINTO, Alane A, VIANA, Rúbia R, AIROLDI, Claudio
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier 15-11-2009
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Infrared and Raman spectra; Infrared and raman spectra and scattering; Materials science; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Physics; Solid surfaces and solid-solid interfaces; Surface treatments; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Equilibrium constant; Liquid solid interface; pH value; Arsenic; Kinetic; Surface treatments; Entropy; Na-magadiite; Arsenic V; Functionalization; Thermodynamic model; Aqueous solutions; Adsorption; Temperature effects; Cations; Adsorption isotherms; Kinetics; Thermodynamic properties
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2009.08.045

A synthetic Na-magadiite sample has been modified by organofunctionalization process using synthetic route involved the reaction of 2-mercaptopyrimidine with 3-chloropropyltriethoxysilane. The ability of these materials to remove As(V) from aqueous solution was followed by a series of adsorption isotherms adjusted to the Langmuir equation at room temperature and pH 2.0. The kinetic parameters analyzed by the Lagergren and Elovich models gave a good fit for a pseudo-second-order reaction with k(2) in the 4.9-14.0mmol(-(1min(-(1 range for M(M(P(Y). The adsorption process was exothermic ((i(n(t)H=-4.09 to -5.79kJmol(-(1) accompanied by increase in entropy ((i(n(t)S=41.29-61.80JK(-(1mol(-(1) and Gibbs energy ((i(n(t)G=-22.34 to -24.19kJmol(-(1). The energetic effect caused by arsenic(V) cation adsorption was determined through calorimetric titration at the solid-liquid interface and gave a net thermal effect that enabled the calculation of the exothermic values and the equilibrium constant.