A portable and high energy efficient desalination/purification system by ion concentration polarization

Abstract

The shortage of fresh water is one of the acute challenges that the world is facing now and, thus, energy efficient desalination strategies can provide substantial answers for the water-crisis. Current desalination methods utilizing reverse-osmosis and electrodialysis mechanisms required high power consumptions/large-scale infrastructures which do not make them appropriate for disaster-stricken area or underdeveloped countries. In addition, groundwater contamination by heavy metal compounds, such as arsenic, cadmium and lead, poses significant public health challenges, especially in developing countries. Existing water purification strategies for heavy metal removal are not readily applicable due to technological, environmental, and economical barriers. This presentation elucidates a novel desalination/purification process, where a continuous contaminated stream is divided into filtered and concentrated stream by the ion concentration polarization. The key distinct feature is that both salts and larger particles (cells, viruses, and microorganisms) are pushed away from the membrane, in continuous flow operations, eliminating the membrane fouling that plagues the membrane filtration methods. The power consumption is less than 5Wh/L, comparable to any existing systems. The energy and removal efficiency, and low cost manufacturability hold strong promises for portable, self-powered water purification/desalination system that can have significant impacts on water shortage in developing/rural part of the world.