EWCO manufactures capacitive deionization (CDI) systems which utitlize membrane CDI technology (MCDI). MCDI is a major variation of the basic CDI cell architecture which is a
cell with two porous electrodes and a separator.
The MCDI architecture utilizes ion exchange membranes on the separator-side of each electrode. As in electrodialysis cells, the feed water channels in MCDI cells are bounded by an anion exchange
membrane (AEM) and a cation exchange membrane (CEM).
EWCO MCDI builds a system with a free-standing CEM placed at the cathode and a free-standing AEM placed at the anode. Alternatively, using the porous electrode as structural scaffold, it is
possible to directly coat the membrane onto the electrode, which can allow for a thinner membrane layer than when using a standalone membrane.
The main benefit of adding membranes to the CDI cell is the improvement of charge efficiency, as the membranes block co-ions from carrying parasitic current, and can increase the salt storage
in electrode macropores. In addition, EWCO membranes may be tailored to have selectivity between different ions of the same charge sign which provides an additional level of tunability for complex multi-ion systems.
EWCO builds MCDI systems with materials that offer the longest life cycles for the capacitors. EWCO membranes are up to one-tenth the thickness of the standard membranes which help to lower operational pressures and
increase ion removal rates. EWCO systems are reliable, high efficiency, and low maintenance therefore ideal for installing for large scale long-term applications treating drinking
water, wastewater, and industrial process water. MCDI provides high contaminant removal efficiencies while achieving high water recoveries, with minimal waste volumes.