Abstract: Disclosed is a process for improved recovery of deionised water from a feed water stream, comprising the steps of (i) delivering the feed water stream in to a capacitive deionisation cell; (ii) measuring the salt concentration of the water exiting the capacitive deionisation cell; (iii) collecting the water exiting the cell, when the salt concentration is lower than a predetermined lower set point, to prepare purified water or rejecting the water exiting the cell when the salt concentration is higher than a predetermined upper set point; wherein the water exiting the cell is recycled with the feed water stream when the salt concentration of the water exiting the cell is between the lower set point and the upper set point. By this process the waste water produced during capacitive deionization can be recycled so as to improve total recovery of water as well as to enhance the life of the electrodes of the capacitive deionisation cell.

Abstract: Disclosed is an electrode an electrode for capacitive deionization comprising • (i) an adsorbent having specific surface area of 100 m 2/g to 1300 m 2/g; • (ii) conductive carbon black; and • (iii) a binder; wherein said adsorbent is impregnated with a substance having conductivity in the range of 105 S/m to 107 S/m and standard hydrogen potential in the range of ?0.3 V to ?1.3 V. The electrode provides enhanced recovery and greater reduction in total solids and is more energy efficient. The process or preparing the electrode and a gravity fed water purification apparatus incorporating said electrode are also disclosed.

Abstract: Disclosed is a process for improved recovery of deionised water from a feed water stream, comprising the steps of: (i) delivering the feed water stream in to a capacitive deionisation cell; (ii) measuring the salt concentration of the water exiting the capacitive deionisation cell; (iii) collecting the water exiting the cell, when the salt concentration is lower than a predetermined lower set point, to prepare purified water or rejecting the water exiting the cell when the salt concentration is higher than a predetermined upper set point; wherein the water exiting the cell is recycled with the feed water stream when the salt concentration of the water exiting the cell is between the lower set point and the upper set point. By this process the waste water produced during capacitive deionization can be recycled so as to improve total recovery of water as well as to enhance the life of the electrodes of the capacitive deionisation cell.