Foam Separation of Phenolate, Orthophosphate, and Dichromate; Batch and Continuous, Multicolumn Operation

Abstract

Results in terms of residual ratios are compared for the batch foam separation from aqueous solution of phenolate, orthophosphate, and dichromate, using a cationic surface-active agent. Effects of pH and of initial surfactant concentration are considered and dichromate is most readily separated. For the single-column foam separation of dichromate in a continuous flow unit, residual ratios are minimized at a feed dichromate concentration of 60 mg/liter, for feed surfactant/dichromate ratios ranging from 3 to 4 g/g. The performances of series, multicolumn units have been calculated in terms of various parameters for feed dichromate concentrations of 25,50, and 100 mg/liter. Better results for single (and multiple) columns could be achieved by using a greater foam height, with the feeds entering at the midpoint of the column of foam.