Heavy metals disposed to aquatic environments is always a major concern worldwide, Because of its adverse effects on human health and ecosystems.[1] Therefore, investigations on the removal of heavy metals from industrial waste water and other effluents are receiving considerable attention.

The contribution of this work is to obtain a series of optimized parameters, controlling a system combining capacitive desalination technique (CDI) with electrodeposition for lead ion removal, to achieve the goal of reducing waste streams in the region of 100 ppm to below 5 ppm; the legal limit in Singapore for discharge of industrial water into public sewers.

In addition, cyclic voltammery analysis was conducted from small scale standard three electrode systems to identify the relative contributions of pure electrical double layer charging and electrodeposition when the current passing through the electrodes. Further more, by designing experiments in the presence and absence of atmospheric CO2 we are also able to show that the formation of lead carbonates is detrimental to the release of lead compounds during the discharge stage of the operation.

Acknowledgment Funding for this work was provided by the Environment & Water Industry Programme Office under grant number 1301-IRIS-33.

References:
[1] L. Jarup, Hazards of heavy metal contamination, Br. Med. Bull. 68 (2003) pp.167-182
[2] Wills, R.G.A., Collins, J., Stratton-Campbell, D., Low, C.T.J., Pletcher, D. and Walsh, F.C.
(2010)Developments in the soluble lead-acid flow battery. Journal of Applied Electroche
mistry, 40, (5),955-965. (doi:10.1007/s10800-009-9815-4).