(397aw) Pollutant Removal From Water By Reduced Graphene Oxide Membranes and Their Electrochemical Regeneration

In current water purification practice, spent adsorbent materials (usually activated carbon) are subject to thermal or chemical reactivation which contributes significantly to the cost of the overall purification process. Reduced graphene oxide (RGO), as derived from the exfoliation of graphite by oxidation followed by its subsequent chemical or thermal reduction, has recently been reported to have exceptional capacity to absorb pollutants from water.  In particular, we utilise the conductivity of RGO to attempt regeneration of spent RGO adsorbents by electrochemical means. Films of conductive RGO, synthesised by vacuum filtration methods, are adsorbed with model pollutants after which, by applying an electrical potential to the spent film, adsorbed pollutants can be removed and the film subsequently re-used. By analysis of the adsorption capacity and by electrochemical impedance spectroscopy, we correlate the electrochemical behaviour of the RGO films with their regenerative capability in order to demonstrate the feasibility of their potential as a unique addition to the suite of water purification methodologies.