What Is Closed Circuit Desalination?

Closed circuit desalination (CCD) is the trade name for a new change in the reverse osmosis (RO) process, explains Rick Stover, Executive Vice President of Desalitech, in an interview with Water Online Radio. RO is an old process that according to Stover, “hasn’t really changed in about 40 years.” His company uses the standard RO components including membranes, pumps, and pressure vessels, but incorporates a design in a CCD system so that it performs very differently. No special equipment is required, but the process and method are patented around the world.

The CCD process works as a semi-batch process, as opposed to conventional reverse osmosis which runs steady-state. It runs at 100 percent recovery so it doesn’t produce any concentrate for a period, then goes through a flush cycle, then resumes closed circuit operation, but never stops the process—the pumps don’t stop, and the permeate production doesn’t stop, Stover said.

Stover believes that industrial segments could greatly benefit from this technology because in the western world, more than 60 percent of fresh water withdrawals go for industrial use, and the rest are for agricultural and domestic use. At the same time, water is becoming scarcer. Quality requirements are becoming higher and there is a need for new sources of water supply.

To hear more about Desalitech and their water treatment technologies, click the radio player below.