(348c) Continuous Water Purification Using Diffusiophoresis in Membraneless Tubular Separators

Water purification is a critical global need in developing nations, isolated communities, and specialty applications. The technological standard in potable water treatment is activated charcoal filtration, with some applications using micro-, ultra-, nano- or reverse osmosis filtration technologies. Such methods are energy intensive, bulky, and require expensive components that are prone to damage or fouling. Diffusiophoresis is an observable phenomena in which particles respond to an ion concentration gradient, inducing physical separation. This phenomenon is exploitable to drive the separation of charged contaminants in water. Using a tube-in-tube-in-tube configuration, a carbon dioxide gradient is developed radially with contaminated water passing through axially. The dissolved carbon dioxide draws the charged contaminant particles towards the outer wall of the reactor, leaving the water near the inner walls purified. This purified water is collected using a syringe and analyzed using a UV/Vis spectrometer. This study demonstrates the effectiveness of a membraneless water purification technique to remove charged polystyrene particles using only a carbon dioxide gradient as a means of contaminant separation.