MUCOR BIOSORBENT FOR CHROMIUM REMOVAL FROM TANNING EFFLUENT

Waste industrial Muco, meihi biomass was found to be an effective bios orbent for the removal of chromium from industrial tanning effluents. Sorption levels of 1.15 and 0.7 mmol/g were observed at pH 4 and 2 res pectively while precipitation effects augmented these values at higher pH ranges. Acid elution of biosorbed chromium increased with decreasi ng eluant pH to a maximium value of ca. 30% at approximately zero pH. Successive elution stages with increasingly strong acids resulted in a cumulative chromium recovery of in excess of 80%. Both acid and base treatments eluted biosorbed chromium and successive acid/base and base /acid treatments resulted in recovery values approaching 100% at low m etal loadings. These values decreased to 80 to 60% at higher biomass m etal loadings. in comparative studies with ion exchange resins, the Mu cor biomass demonstrated chromium biosorption levels that correspond c losely to those of commercial strongly acidic exchange resin while the pH behaviour mirrored that of the weakly acidic resins in solution. T he chromium elution characteristics from the Mucor biomass were simila r to those of both the weakly and strongly acid resins. (C) 1998 Elsev ier Science Ltd. All rights reserved.