STUDY OF CARBON BASED ELECTRODES IN CAPACITIVE DEIONIZATION FOR DESALINATION

The world’s increased concern for fresh water resource availability drives research in desalination. Capacitive deionization (CDI) is a method of water desalination where a voltage is applied to carbon electrodes resulting in salt ion adsorption. The desalination performance of three different carbon based electrodes, incorporating graphite felt, silica nanosprings, and a conductive thin film GUITAR are studied. Surface area of the bare graphite felt is improved from 0.8 m2/g to 2.6 m2/g when coated with GUITAR, and estimated near 22 m2/g when incorporating silica nanosprings. A modified Hummers method is used to enhance capacitance of GUITAR by over 15 times. Leakage current is eliminated from CDI cell charging by operating at reduced voltages. Maximum salt adsorption is achieved using bare graphite felt, suggesting the non-porous nature of GUITAR. Also presented is a new CDI cell design and mathematical model of ion motion in electric and magnetic fields.masters, M.S., Mechanical Engineering -- University of Idaho - College of Graduate Studies, 2017-0