Adsorption of 5.5’-Disulfonicindigotin (5.5’-DI) onto Green Coconut Fiber (Cocos nucifera L.): Kinetic and Isotherms

Abstract

Green coconut fiber (Cocos nucifera L.) has been largely used in solid-phase extraction. The effect of the initial dye concentration (1.91, 3.02 and 4.02) × 10-5 mol&#183L-1 and solid phase contact (SPE) time were evaluated at different temperatures (283, 298 and 313) K at pH 2. Kinetic experimental data were applied to three simplified kinetic models: pseudo-first order, pseudo-second order, and intraparticle diffusion. The adsorption of 5.5’-DI onto the solid phase showed excellent fit to the pseudo-second order model. At 283, 298 and 313 K the maximum sorption, qmax,exp, for the lowest initial concentration (Co = 1.91 × 10-5 mol&#183L-1) of 5.5’-DI were (5.01, 5.24 and 6.14) × 10-4 g&#183g-1; for Co = 3.02 × 10-5 mol&#183L-1 (0.93, 1.01 and 1.03) × 10-3 g&#183g