Correlative biosorption equilibria model for a binary batch system

The binary sorption of copper and nickel ions onto peat has been studied. E quilibrium isotherms have been determined for three different copper : nick el molar concentration ratios. The experimental results have been analysed using an extended multicomponent Langmuir equation with a competition term but the correlation between the experimental and the predicted values was p oor. An interaction factor was incorporated into the extended Langmuir equa tion and a significant improvement in correlation was obtained. The final m odel involved deriving an expression to correlate the interaction factor wi th surface loading and these correlations produced coefficients greater tha n 0.995 for all the isotherms. An F-test on the variable interaction factor model developed in this paper confirmed that it produces a significant imp rovement in correlating isotherm equilibria data. (C) 1999 Elsevier Science Ltd. All rights reserved.