Power Plant Wastewater Cleanup through Capacitive Deionization

Power plant wastewater is a complex mix of dissolved ionic content resulting from various impurities present in the coal as well as corrosion products from steel equipment. Multifaceted water treatment processes are currently used to lower contaminant concentrations, but stricter regulations will further decrease the allowable discharge limits. To address this issue, the use of a capacitive deionization (CDI) process is shown which can effectively deionize various power plant wastewater and solvent streams. Carbon xerogel electrodes synthesized with a range of pore sizes and a conductive, flexible carbon support enables the capture of both monovalent and divalent species from waste streams. Electrosorption capacities of 2-4 mg NaCl/g of xerogel have been shown with carbon surface areas between 140-240 m2/g.