COLOR REMOVAL FROM AQUEOUS-SOLUTIONS .1. FLOTATION

The removal of colours from aqueous solutions and/or dispersions has b een studied by dispersed-air flotation, in a semi-batch flotation colu mn. Three colours were used for the experiments: Basic Yellow 28 (acid ic), Direct Black 22 (basic) and Disperse Orange 30 (dispersion colour ). All three were effectively removed by flotation within 15 to 30 min . Sodium lauryl sulfate and dodecylamine were found to be effective as collectors in the removal of colour, which was also found to be relat ed to the pH of the solution and the amount of collector added to it, with high collector dosages causing the process to become pH-independe nt.