Biosorption of chromium vi nickel ii Copper ii and cobalt ii from Aqueous solution using Bacillus subtilis Pseudomonas aeruginosa AND Enterobacter cloacae

Abstract

The presence of toxic heavy metals in industrial effluents has become a matter of environmental concern. The major sources of heavy metal contamination are effluents from industries like electroplating, smelting, alloy manufacturing, silver refineries, pigments, plastic, battery, mining and refining processes. Heavy metal concentrations beyond permissible levels are hazardous. Three different biosorbent materials of bacteria - Bacillus subtilis, Pseudomonas aeruginosa and Enterobacter cloacae were used as biosorbents for comparison and determination for the removal of Cr(VI), Ni(II), Cu(II) and Co(II) ions from aqueous solution. In the biosorption of heavy metal ions; effect of pH, biosorbent dosage, metal ion concentration, contact time, biosorption isotherm and kinetics studies were carried out. The metal ion concentration were analyzed using Atomic absorption spectroscopy, the biosorbent were characterized by Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) techniques. The results of biosorption studies are The solution pH usually plays a major role in biosorption and affects the solution chemistry and also the heavy metal activity of the functional groups of the biomass. Heavy metal ions concentration seems to have impact on biosorption, with a higher concentration resulting in a higher solute uptake. This is because at lower initial solute concentrations, the ratio of the initial moles of solute to the available surface area is low; subsequently, the fractional sorption becomes independent of the initial concentration. The biosorption of three different bacteria such as B.subtilis, P.aeruginosa and E.cloacae were analyzed by scanning electron microscopy to understand its surface morphological characterization of the biosorbent before and after biosorption was carried out. The comparison of SEM pictures between the natural and metal loaded biosorbent shows that the particle has undergone remarkable physical disintegration after adsorption in all the three biosorbents.