Community Research and Development Information Service - CORDIS

Removal of metal ions from aqueous solutions by adsorbing flotation

The removal of heavy and toxic metals from dilute aqueous solutions was investigated in the laboratory. The process often termed adsorbing (or sorptive) flotation involves the abstraction of metal ions onto sorbents, at fine or ultrafine size range, followed by a flotation stage for the separation of metal-loaded particles. The sorbents used in the process first stage were either conventional or may be industrial solid wastes and by-products (ie from the mineral, pharmaceutical industries, fermentations, etc).

In this way, a treated clear water is produced as underflow and a foam concentrate; even the recovery of metals is possible from the latter, leading to clean technology. If required, the sorbents may be recycled after metal desorption, which also revealed no problem. Various flotation techniques were applied effectively.

The ability of microorganisms to remove metal ions from solution is a well known phenomenon; industrial applications of biosorption often make use of dead biomass, which does not require nutrients and can be exposed to environments of high toxicity. Non-living biomass showed greater binding capacities for cadmium than the living one. Extensive experimental batch results were also conducted with actinomycetes fungi and activated sludge as the metal biosorbents.

Reported by

Aristotle University
54006 Thessaloniki
Follow us on: RSS Facebook Twitter YouTube Managed by the EU Publications Office Top