EQUILIBRIUM SORPTION OF CR6+ BY A CONSORTIA OF DENITRIFYING BACTERIA

The accumulation of metal ions on to biological materials is a promisi ng method for removing these toxic materials from waste or ground-wate rs. A fractional factorial statistical experimental design was used to ascertain which experimental parameters affect the sorption of Cr6+ b y a consortium of denitrifying bacteria using a minimum number of expe riments. Analysis of this set of experiments found that the steady sta te sorption behavior could be described by Langmuir isotherms. Observe d variations in the isotherm parameters were due to the imposed change s in the experimental variables. In particular, solution pH and the st ate of the biomass were found to have the greatest influence upon the amount of chromium that was taken up, while other factors had less sig nificance. but were still important.