Characterization of an Extracellular Biopolymer Produced by Pseudomonas Fluorescence C-9 and Its Use for Cobalt and Cadmium Removal

In the present study we reported the feasibility of extracellular biopolymer(PF-9) produced by Pseudomonas fluorescence C-9 as an alternative biosorbent to remove Co(II) and Cd(II) metallic ions from environmental and industrial wastewater. The ability of PF-9 to remove the metallic ions was investigated by using batch biosorption procedure. The effects such as, pH, biosorbent dosage, sorbate concentrations and sorbate-sorbent contact time on the adsorption capacities of PF-9 were studied. Biosorption equilibriums were rapidly established in about 60 min and the adsorption kinetics followed the pseudo-second order kinetics model. The equilibrium adsorption data fitted well with Langmuir isotherm. The maximum Co(II) and Cd(II) adsorption capacity determined from Langmuir isotherm were 64.52 and 86.20 mg /g PF-9 at pH 5.0 ,at 25±2°C and shaker speed 150 rpm, respectively. The carboxyl ,hydroxyl and amino groups of the PF-9 were involved in chemical interaction with the Co(II) and Cd(II) ions depicted by scanning electron microscopic (SEM) and Fourier transform infrared spectroscopic (FTIR) results. The study points to the potential of new use of extracellular biopolymer PF-9 as an effective sorbent for the removal of Co(II) and Cd(II) from environmental and industrial wastewater.