Chrome-IX™ is an innovative chromium removal technology developed by Tonka Water for the removal of both hexavalent and trivalent chromium. Awareness about the dangers of hexavalent chromium has resulted in new regulations for drinking water treatment, especially in California where the MCL is 10 µg/l, and the total chromium MCL is 50 µg/l. Elsewhere in the US, total chromium is regulated at the US EPA MCL of 100 µg/l.

The main advantages to Chrome-IX™ include no generation of hazardous waste, infrequent vessel regenerations, and extremely long resin life. No proprietary resins are used with Chrome-IX™, and the sodium sulfate regenerant is recycled on site. Additional advantages to Chrome-IX™ are that standard resins can be used and no sodium chloride brine is used, so there is no brine for disposal.

Tonka Water uses a strong base anion exchange process, placing the resin in sulfate form, allowing for the Chrome-IX™ system to capture chromium. After capture and during regeneration, all collected chromium is converted to trivalent chromium, which can be affixed to a chelating resin for safe non-hazardous disposal.