Studies on Biosorption of Chromium Ions from Wastewater Using Biomass of Aspergillus niger Species

Abstract

he biosorption capacity of immobilized biosorbents for Cr (VI) was found to depend on pH, contact time, biosorbent dose and initial concentration of Cr (VI). In this study, the maximum uptake of Cr (VI) was 93.4, 96.2 and 98.6 mg respectively at a pH 1.5 and with an increase in pH up to 11 the metal uptake decreased gradually upto 39.95, 52.35 and 66.48 mg respectively for acid treated, untreated and base treated fungal biosorbents.Increase in biosorbent dose up to 1g of biomass and contact time up to 60 min resulted in an increase in biosorption from 20.2, 16.8 and 28.3 mg at a biosorbent dose of 0.1g 100 ml-1 to 93.4, 96.2 and 98.6 mg at a biosorbent dose of 1.0 g 100 ml-1 and then further increase in adsorbent dose and contact time did not result in more Cr (VI) adsorption by per unit weight of biosorbent.