Application of Capacitive Deionisation in water desalination: A review

This manuscript spans over 180. years of ideas, discoveries, inventions, breakthroughs and research in Capacitive Deionisation (CDI) and Membrane CDI (MCDI) desalination. Starting with the first discovery of the dissociation of ions in solution under an electric field by M. Faraday (1833), through the pioneering work of carbon aerogel flow through capacitors by J. Farmer's group (1996) at Lawrence Livermore National Laboratory (LLNL), to the utilization of novel graphene and carbon nanotube (CNT) materials as electrodes, the CDI and MCDI technologies are progressively making its path to the desalination industry. Through this review various deficiencies of this technology have been identified, first and far most was the need for low cost and efficient electrode materials. The review identified that a low cost and high efficiency electrode capable of processing high salinity (seawater) stream still does not exists and is considered important if the technology is to make it to the industry. Furthermore, the lack of long term reliability, operation demonstrations and experience meant that information about scaling and fouling are rather scarce. Taking a step further, no comprehensive environmental assessment such as Life Cycle Assessment (LCA) or Environmental Impact Assessment (EIA) has been performed yet.