Sorption of Cr(VI) from dilute solutions and wastewater by live and pretreated biomass of Aspergillus flavus

Abstract

Sorption of Cr(VI) was carried out from dilute solutions using live and pretreated biomass in a batch mode. Effects of agitation time, adsorbent dosage and pH were examined. The autoclaved biomass that showed maximum adsorption capacity ( Q 0 = 0.335 mg g −1) was used as an adsorbent in column studies. The optimized flow rate of 2.5 ml min −1 and bed height 10 cm were used to determine the effect of metal ion concentration on removal of Cr(VI). Applying the BDST model to calculate the adsorption capacity ( N 0) of column, which showed 4.56 × 10 −5, 7.28 × 10 −5, 6.89 × 10 −5, 3.07 × 10 −5, 2.80 × 10 −5 mg g −1 for 4, 8, 12, 16 and 20 mg dm −3 of Cr(VI), respectively. Batch sorption proved to be more efficient than the column sorption and hence batch sorption was used to remove Cr(VI) from a textile dyeing industry wastewater. The phytotoxic effect of treated and untreated wastewater was studied against Zea mays. Toxicity was reduced by 50% in the treated effluent.