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, Q0 and b were observed to be 57.1 mg/L
and 0.06 l 1/mg, respectively.