Metal ion separation and recovery from environmental sources using various flotation and sorption techniques

Flotation is a gravity separation process that originated from processing of minerals, and has nowadays found wide application, for instance, in industrial waste-water treatment. It is also useful in the concentration of a variety of dissolved chemical species often following a sorption process. The present review paper focuses on the removal of heavy metal ions from aqueous solution. The process mechanisms involved are either sorptive flotation where metal bonding agents, including biosorbents, are added and the subsequent complexes are separated downstream by flotation or other conventional flotation techniques, such as ion flotation are used. In the laboratory experiments described in this paper, zinc has been used as an example, but in addition copper, nickel, arsenic, etc. are considered. A new hybrid flotation-microfiltration cell is also introduced. (C) 2010 Society of Chemical Industry