An important issue in potable water processing is the need for removal of trace organic chemicals. Conventional water treatment (coagulation/ flocculation/ sedimentation/ filtration) and chlorination is not always effective in the removal of these compounds. An approach that has been proposed for the purpose is advanced oxidation employing photochemical reactions at the surface of a photocatalyst such as TiO2 [[i]].
Since the photochemical oxidation reaction is a surface reaction, to achieve sufficient flow rates it is imperative to increase the surface to volume ratio of the reactor, and we have investigated employing microstructured reactors implementing these advanced oxidation processes. An approach that has been employed to activate reactions in macroscale reactors is the use of electric discharge through the reaction medium which leads to the creation of highly reactive species as a consequence of the electrical discharge [[ii]] as an alternative to photocatalyzed approaches. We have therefore developed a microreactor employing a low voltage corona discharge for the disinfection and organic compound oxidation in water, a technique that moves the oxidation reaction from the surface of the reactor to the bulk of the fluid, thus increasing process efficiency.
In our presentation we will discuss recent results of the use of microstructured reactors for the advanced oxidation of organic contaminants in water.
[i] Ollis, D.F.; Pelizzetti, E.; Serpone , N. “Destruction of water contaminants” Environ. Sci. Technol. 1991, 25, 1522-1529.
[ii] Kirkpatrick, M. J.; Locke, B. R. “Hydrogen, Oxygen, and Hydrogen Peroxide Formation in Aqueous Phase Pulsed Corona Electrical Discharge” Ind. Eng. Chem. Res. 2005, 44, 4243-4248.
See more of this Group/Topical: Topical 1: Water Technology for Developed and Developing Countries (see also Separations Division)