Biosorption of Cr [VI] by resting cells of Fusarium solani

ABSTRACT

Chromium is one of the toxic heavy metals which exists in nature as stable hexavalent and trivalent forms. The hexavalent form of chromium is more toxic than trivalent chromium as it persists indefinitely in the environment complicating its remediation. The conventional physical and chemical treatment techniques used for the removal of Cr[VI] are expensive and highly energy intensive, moreover they produce harmful by-products, ultimate disposal of which again causes secondary pollution. Removal of Cr[VI] from aqueous solution using biological sources as biosorbent has assumed advantageous over the existing conventional physico-chemical techniques for the treatment of metal contaminated wastes. The present batch biosorption study was undertaken with an aim to examine the Cr [VI] removal potential of the resting cells of Fusarium solani [isolated from soil] from aqueous solution. The specific Cr [VI] removal decreased with increase in pH and increased with increase in initial Cr[VI] concentration, up to 500 mg/L. The specific Cr[VI] removal remained almost constant by increasing biomass concentration from 2.4 to 5.2 g/L. The studies also carried out by using the resting cells obtained from various stages of growth and the maximum specific Cr[VI] removal [60 mg/g] was achieved at 500 mg/L initial Cr[VI] concentration and by using cells [36 h old]. The Langmuir adsorption isotherm constants, Q[o] and b were observed to be 57.1 mg/L and 0.06 I 1/mg, respectively