3-D electrolytic cell provides new option for wastewater recycle waste minimization

摘要

The cell design of a patented electrolytic technology, commercialized in 1999, allows effective use of three-dimensional porous cathodes to remove and recover metals. The cell's 3-D porous cathode has greater than 500 times more effective surface area than a 2-D electrode of the same nominal size. This high surface area allows metal deposition at higher current efficiencies, lower current densities and higher deposition rates, and thereby achieves lower final metal ion concentrations. This advanced technology has demonstrated the following: the capability to achieve metal discharge limits without further treatment; the collection of these metals as elements ready for sale or reuse; the use of removable cartridges for ease of operations and maintenance; and the reduction of life cycle costs. While this technology can be applied in a variety of ways, ranging from process water treatment to metal recovery to effluent treatment, the potential of water recycle and waste minimization is being realized today. For example, the cell is being placed at point sources of copper and other metal releases, including metal plating drag-out and rinse tanks. Instead of these waters being released to waste treatment, the cell recovers the metal at the sources and allows the rinsewater to be used longer, thereby reducing water consumption and discharges, all at a substantial cost advantage over conventional technology. Several applications and experiences are presented, with a focus on heavy metals (Cd, Cu, Pb and Ni).