Biosorption of hexavalent chromium by Pleurotus ostreatus

Abstract

The existing techniques for the removal of heavy metals are expensive and frequently inefficient. Thus the application of biosorbents has arisen as an alternative, this being emergent technology that must be studied and explored, with the aim of promoting better environmental and human life quality. The objective of this study was to verify the capacity of active and inactive Pleurotus ostreatus fungal biomass in removing Cr(VI) ions by biosorption from synthetic aqueous solutions of these ions at concentrations of 10, 25, 50, 75, 100, 125 and 150 mg L -¹. When using active biomass, the kinetic studies showed that 100% of biosorption was reached from the 25 mg L-¹ Cr(VI) solution in 360 hours, equivalent to the removal of 169.84 mg g 1 of total Cr. On the other hand the inactive biomass reached 100% of its saturation capacity in 22 minutes for a concentration of 50 mg L-¹ of Cr(VI), equivalent to the removal of 368.21 mg g 1 of total Cr. The kinetic study was shown to be highly effective, presenting an efficiencies of times 500 and 750 for the active and inactive P. ostreatus biomasses, respectively, when compared to the limit of 0.1 mg L-¹ of Cr(VI) for industrial effluents described in CONAMA resolution n 430/2011.