Capacitive deionization of metal-contaminated water and seawater using graphene/activated carbon composite electrodes

  • 鍾 力剛

Student thesis: Master's Thesis

Abstract

Fresh water shortage is a serious problem which is getting worse in recent decades Desalination technologies is essential because of ocean has 97% of water resources on the earth Capacitive deionization (CDI) is a promising technology has advantages of low energy consumption and environmental friendly Ions can be removed from water by applying a potential different between two electrodes The electrical double layer form on the electrodes surfaces can store the ions CDI can also used to treat the contaminated underground water and diluted wastewater The CDI performance is influenced by the characteristics of electrode materials such as conductivity specific surface area and wetting ability In this study activated carbon (AC) (recovered from palm shell wastes) was used as CDI electrodes To promote deionization efficiency rGO and (Cu-ZnO)@C nanoparticles composite based electrodes were also used for CDI of contaminated underground waste and brackish waters (50-5000 mg/L) During repeated CDI their regeneration abilities were investigated The carbon electrodes can be regenerated by removing the voltage or reversing the polarity For the high salinity water the electrosorption becomes saturation in a short time Nevertheless the electrodes regenerated by reversing polarity possess a relatively slow step The positive electrode surface may involve oxidation during CDI which can be reduced by reversing the polarity
Date of Award2016 Aug 31
Original languageEnglish
SupervisorHong-Paul Wang (Supervisor)

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