Colloidal gas aphrons (CGAs) were first proposed by Sebba (1971) as micro b
ubbles (10-100 mum), composed of a gaseous inner core surrounded by a thin
surfactant film. CGAs are created by intense stirring (usually over 5000 r(
.)min(-1)) of a surfactant solution. Flotation of Cu(II) by colloidal gas a
phrons has been conducted in order to explore a new method for separating h
eavy metal ions from dilute solution. The effects of CGA flow rate, amounts
of CGA introduced to the system, surfactant concentration on the flotation
efficiency have been investigated. The results show that the flotation eff
iciency at pH = 5-6 has an optimum value to CGA flow rate and amount. When
pH is greater than 7, the flotation efficiency can be as high as 99% at the
optimum condition.