Kinetic studies on the biosorption of phenol by nanoparticles from Spirulina sp. LEB 18

Abstract

A kinetic study on the biosorption of phenol by nanoparticles from Spirulina sp. LEB 18 was carried out. The Spirulina sp. nanoparticles were prepared and characterized. Kinetic curves of phenol biosorption were obtained in batch system, being verified the effects of initial concentration (50, 150, 250 and 450 mg L 1) and stirring rate (50, 200 and 400 rpm). The models of pseudo-first order, pseudo-second order, Elovich, Bangham, general order and Weber–Morris were used for the kinetic interpretations. Spirulina sp. nanoparticles were stable, monodisperse, spherical with mean diameter of 230 nm. The phenol biosorption was a relatively fast process, being favored at higher values of initial concentration and stirring rate. Pseudo-second order and general order models showed satisfactory fit with the experimental data and the maximum biosorption capacity was around 101 mg g 1. From the Weber– Morris analysis, it was found that external mass transfer and intraparticle diffusion occurred during the phenol biosorption on Spirulina sp. nanoparticles. The externalmass transfer was faster at higher values of initial concentration and stirring rate, and the intraparticle diffusion was favored at high initial concentrations.