Selective Separation of Heavy Metals from Industrial Wastewater Streams by Means of Heavy Metal Bonding Agents

Industrial wastewater is often contaminated with heavy metals and must undergo expensive and elaborate treatment. A new, environmentally friendly process, which allows both metals and water to be reused, has been developed. It comprises the following three process stages: firstly, a metal bonding agent (BA) is added to the wastewater to bind the heavy metal; secondly, the loaded BA is separated by ultrafiltration/microfiltration or a new hybrid process involving flotation and membrane filtration; and thirdly, the BA is regenerated. The first results from the characterisation of selected BAs (synthetic hydrotalcites and synthetic zeolites) in terms of their bonding kinetics, maximum loading capacity and regeneration potential are presented.