Capacitive Deionization -- defining a class of desalination technologies

Over the past decade, capacitive deionization (CDI) has realized a surge inattention in the field of water desalination and can now be considered as animportant technology class, along with reverse osmosis and electrodialysis.While many of the recently developed technologies no longer use a mechanismthat follows the strict definition of the term "capacitive", these methodsnevertheless share many common elements that encourage treating them withsimilar metrics and analyses. Specifically, they all involve electricallydriven removal of ions from a feed stream, storage in an electrode (i.e., ionelectrosorption) and release, in charge/discharge cycles. Grouping all thesemethods in the technology class of CDI makes it possible to treat evolving newtechnologies in standardized terms and compare them to other technologies inthe same class