(50d) Water Treatment by Adsorption with Electrochemical Regeneration

Roberts, E. P. L., University of Manchester
Hussain, S. N., University of Manchester
Asghar, H. M. A., University of Manchester
Mohammed, F. M., University of Manchester
Conti-Ramsden, M., University of Manchester
Brown, N. W., Arvia Technology Ltd
Campen, A. K., Arvia Technology Ltd

An innovative process for water treatment using adsorption and electrochemical regeneration has been developed at the University of Manchester. A spin-out company, Arvia Technology Ltd. has been established to commercialise the technology. The process uses a graphite based adsorbent, Nyex® which has a low adsorptive capacity in comparison to many industrially used adsorbents. However, the material has a high electrical conductivity allowing electrochemical oxidation of adsorbed contaminants and 100% regeneration of its initial adsorptive capacity. It has been shown that a packed bed of Nyex® loaded with an organic contaminant can be regenerated in the anodic compartment of an electrochemical cell in around 10 minutes. Furthermore, the charge required for regeneration is approximately equal to the theoretical charge for complete oxidation of the organic. Unlike wastewater oxidation at a plate electrode, the breakdown products remain adsorbed on the surface of the Nyex® and are not released into solution. The rapid regeneration and low energy consumption make the process attractive for a wide range of water treatment applications. The process uses no chemicals and does not produce any solid or liquid wastes. Continuous and sequential batch treatment processes have been developed and these are currently being used in a series of industrial trials. In this paper, studies of the treatment of water contaminated with an organic dye, phenol, and mercaptans will be described, including analysis of any breakdown products present in the liquid and gas phases. In addition a preliminary study of the effectiveness of the process for disinfection will be reported.