Regeneration of Exhausted Carbon Nano-Foam used in Desalination of Brackish Water

Carbon Nano-Foam (CNF) has been used electrochemically for water desalination. CNF electrodes attract oppositely charged ions flowing in between them and this process is known as Capacitive De-Ionization (CDI). Once saturated these electrodes lose electrochemical adsorption and need to be replaced, this increases the cost of the treatment process as CNF is expensive. The goal of this study is to obtain optimal regeneration and predictive capability by examining CNF electrodes during regeneration and developing a model to describe desorption behavior. Various experiments were conducted to explore the effect of shorting, changing polarity of electrodes, flow velocity of water over CNF electrodes and use of hot water on regeneration of CNF. Data collected during these tests was used for modeling regeneration behavior of CNF. HSDM model for kinetics of removal of ions and regeneration of CNF and Langmuir model for describing the equilibrium was seen best fit