Selective removal of nitrate ions by controlling the applied current in membrane capacitive deionization (MCDI)

Desalination with porous electrodes : Mechanisms of ion transport and adsorption

“…3 in Ref. [28]), a period which is slightly delayed relative to the period of cell charging. Instead, in prior work discussing short cycle times [25,27,45] salt adsorption (desorption) was calculated based on the period of cell charging (discharging).…”

“…5a and b, we use the ''new data analysis approach'' discussed in Ref. [28], where the salt adsorption is based on the entire time period that the effluent salt concentration is below the inflow concentration (period from A to B in Fig. 3 in Ref.…”

“…Furthermore, there is an increasing interest to apply desalination methods to remove specific charged compounds from aqueous streams, for instance, the removal of NO -3 , a harmful compound, when present in high concentrations in e.g. drinking water [28]. In this Thesis, we will, after introducing CDI technology in the following sections, address several of these aspects to investigate the suitability of CDI as a method of desalination.…”

“…1.11. Recent scientific developments are on electrode materials [11,33,51,[88][89][90][91][92][93], novel cell designs, ranging from desalination with wires [80] to flow electrodes [5,72,73], or on new operational modes or ion-selective removal [28,47,[94][95][96]. Also, studies are conducted to quantify resistances and energy losses in the CDI cell [4,97,98], or to identify parasitic reactions that may result in pH changes [8,[99][100][101].…”

“…Alternative designs use carbon electrode wires [80], flowable electrode slurries [7,[72][73][74]76] or flow-through electrodes [112]. In addition, electrodes can be chemically modified [88,113], nanoparticles can be incorporated [114][115][116], ion-selective coatings can be applied [117,118], or ionexchange membranes can be placed in front of the electrodes in a modification called Membrane Capacitive Deionization, or MCDI [27,28,35,71,102,[119][120][121].…”