Separation and recovery of binary heavy metal mixtures in aqueous solutions

Removal and recovery of heavy metals from industrial waste waters is a quite important process and many different methods are applied for this. Parametric Pumping which is developed at that work and is an ion exchange process applied by different complexing agents and pH parameters, allows heavy metals from mixed waste solutions to be recovered as a single components and therefore to be recycled. Parametric Pumping which is dependent on the variation of the pH is an innovative ion exchange process. The process is based on the addition of a complexing agent to the mixture, on its separation into two half volumes and a periodic contact of an ion exchanger with both liquid phases. At that work in order to get the separation of binary divalent metal systems like Ni-Cd , Cu- Co and Cu-Ni , using citric acid and tartaric acid as a complexing agents , the most suitable complexing agent and pH optimization have been investigated. The experiments have been carried on two different pH values ; at low pH ( < 3) and at high pH ( > 5). The kinds of metal species forming more stable complexes are concentrated in the high pH solution, the other ones forming less stable complexes are concentrated in the low pH solution. In the last step the optimum conditions that are found were applied to industrial waste waters. Keywords: Parametric pumping, ion exchange, heavy metals, complexing agents, separation of mixture