Adsorptive Removal of Pb(II) by a Novel Extracellular Biopolymer Produced by Pseudomonas Fluorescence: Equilibrium and Kinetics

Abstract

An extracellular biopolymer (PS-2) produced by Pseudomonas fluorescence C-2 was used as an alternative biosorbent to remove toxic Pb(II) metallic ions from aqueous solutions. The prepared biosorbent PS-2 were characterized by FTIR and SEM. The effect of experimental parameters such as pH, dosage of biosorbent , Pb(II) initial concentration and contact time on the adsorption was studied. It was found that pH played a major role in the adsorption process, the optimum pH for the removal of Pb(II) was 6.0. SEM images showed that the surfaces of particles was rough and irregular with large area for metal-surface interaction, the FTIR spectra showed carboxyl , hydroxyl and amino groups of the PS-2 were involved in chemical interaction with the Pb(II) ions. Equilibrium studies showed that Pb(II) adsorption data followed Langmuir model. The maximum adsorption capacity (qmax) for Pb(II) ions was estimated to be 94.58 mg/g. The kinetic studies showed that the kinetic rates were best fitted to the pseudo-second-order model. The study suggestted that the novel extracellular biopolymer biosorbent have potential applications for removing Pb(II) from wastewater.