Capacitive Deionization (CDI) is a deionization process used to desalinate feedwater (different than EDI used as a final polishing step in ultrapurification). CDI has the advantage of operating at a high recovery rate up 95% and at high temperatures above 45°C (110°F). The TDS in the permeate can be electronically adjusted.
Applications for CDI include removing TDS from feedwater for use in cooling towers and boilers and from industrial wastewater for reuse. CDI is beneficial in the recovery and reuse of high temperature wastewater in industrial laundry applications.
A CDI module contains multiple stacks of parallel unit cells with each cell consisting of an anode and cathode electrodes separated by a feed spacer. The electrodes are covered with selective ion exchange membranes. Feed water flows through the spacer between the membranes. By Applying an electrical potential idfference between two electrodes, ions are removed from the feed water.
Ions are removed from the electrodes during regeneration by reversing the applied voltage. A concentrate stream flushes the released ions from the CDI module.
Applications are limited to feedwater with a salt concentration of up to 4000 ppm TDS. However, because only the ions pass through the membrane (and not the water), is less susceptible to fouling than RO due to total organic carbon (TOC) and chemical oxidant demand (COD) in the feedwater.
For more information on how we may be able to assist you contact an Aqua Clear Water Treatment Specialist today. Our staff can help identify and troubleshoot any inefficiencies that are occurring in your water treatment system to help you save on capital and operating costs.
The CDI system is a skid-mounted full turnkey unit that is ready to use upon delivery with only simple piping and wiring connections needed. As a one stop shop, Aqua Clear’s water treatment specialists will engineer a complete solution based on the client’s feedwater quality including pretreatment and post-treatment options.
With an eye on “ONE WATER” solutions, Aqua Clear has many programs and capabilities to provide our clients with peace of mind. Aqua Clear’s water treatment specialists have the knowledge for onsite reuse of process wastewater using CDI combined with other technologies.
Our #1 product to this very day is our service. Aqua Clear offers preventative maintenance and remote monitoring & control. We can provide year-round service and/or operation of the water treatment system to support your facility.
