The Difference Between Deionized and Reverse Osmosis Water Purification

Deionized (DI) and reverse osmosis (RO) are two popular methods used for water purification. While both methods remove impurities and contaminants from water, they differ in the way they work and the types of contaminants they remove.

Deionization, also known as ion exchange, removes charged particles, such as minerals and ions, from water by passing them through a resin bed. The resin exchanges ions with the incoming water, removing dissolved solids, minerals, and other impurities. The result is water that is free of minerals but may still contain organic compounds, bacteria, and viruses.

Reverse osmosis, on the other hand, uses a semi-permeable membrane to filter out impurities. Water is forced through the membrane at high pressure, leaving behind contaminants that are larger than the membrane pores. Reverse osmosis systems can remove a wide range of impurities, including minerals, salts, organic compounds, bacteria, and viruses.

In terms of efficiency, reverse osmosis is generally more effective than deionization at removing contaminants. Reverse osmosis can remove up to 99% of dissolved solids and minerals, while deionization typically removes 90-95% of dissolved solids. However, deionization is often used in combination with reverse osmosis to provide an extra level of purification.

Another difference between the two methods is the cost and maintenance requirements. Deionization systems are generally less expensive and require less maintenance than reverse osmosis systems. However, the resin bed in deionization systems must be replaced periodically, which adds to the overall cost.

Overall, both deionization and reverse osmosis are effective methods for water purification, but they differ in their ability to remove contaminants and their maintenance requirements. The choice between the two methods will depend on the specific needs of the user and the quality of the water source.