Selective Metal Removal with Capacitive De-ionisation

点击翻译按钮获取中文摘要

Capacitive deionisation (CDI) has emerged as a promising way to desalinate water, and indeed remove a range of pollutants such as heavy metals. The principle of the method is simple: a voltage is applied to high surface area electrodes, and ions are adsorbed "capacitively" on the surfaces. Modification of surface chemistry allows for ion-selectivity, through either capacitive or Faradaic effects. Although the method is believed to be comparable (in energy, and potentially, cost terms) to alternative separation methods (nano-filtration, reverse osmosis or traditional distillation), many underlying scientific questions - about the structures formed within the porous electrodes and the theoretical limits of the approach - are unanswered to date.Scientifically, the key initial task for this project will be to explore how soluble species can be removed selectively and the limits on the recovery (both high and low concentrations limits). Strategies to be pursued will involve purely capacitive metal removal, or Faradaic (electrodeposition) removal of metals, coupled with capacitive counter-ion removal. The longer-term goals will be to establish the limits of the CDI approach from a fundamental electrochemical perspective.