Deionized Water System vs Reverse Osmosis: Which is Best For Your Application?

There are many different filtration systems for water, two of the most common being reverse osmosis and deionization. While they are both effective in substantial ways, several misconceptions surround both of these processes. Here, the team at Reynolds Culligan clarifies how these systems work and answers frequently asked questions we receive about them to ensure you know which service is best for you.

Deionization and reverse osmosis are both excellent at removing dangerous contaminants and minerals from water. Depending on the specifics of the system and the filtration stages involved, these systems can purify water by removing things like:

• Salt
• Sand and silt
• Copper and iron
• Arsenic
• Magnesium and calcium

Both are useful for cleaning because they don’t leave behind streaky mineral deposits. They also perform well in boilers and humidifiers, and they’re great in industrial application such as cosmetics, manufacturing, and aquariums.

The biggest difference between the two is that reverse osmosis uses a semipermeable membrane to filter water, while deionization uses ion exchange resins to replace minerals and contaminants with hydrogen and hydroxyl ions.

While both filtration systems offer approximately the same ability to remove contaminants from water, only reverse osmosis can remove protozoa, viruses and bacteria from the water. What deionization does have over reverse osmosis is that it can act as a water softener as well as a purifier.

Reverse Osmosis

Reverse osmosis systems use pressure to reverse the flow of water, so the water passes through a membrane and carbon filters to filter out chemicals, bacteria, and minerals. If you live or work in an area where heavy pesticides or herbicide use is an issue, reverse osmosis can remove these substances from your water.

The U.S. military has used reverse osmosis to change salt water into fresh water for troops, and some countries use this technology during floods and relief efforts to help communities stricken by the disasters. The “pure water” created from the system also aids the environment by curbing the need for bottled water and the plastic waste left behind.

There are some drawbacks to reverse osmosis systems. Some of the minerals stripped from the water, such as iron, calcium, manganese, and fluoride, are beneficial for humans and may lead to vitamin deficiencies in people with less well-rounded diets. A lack of fluoride in the water can also lead to a higher chance of cavities in children.

Deionized Water

Deionization is a water treatment process that targets mineral salt contaminants. The purification process removes cations, such as calcium, copper, iron, sodium ions, and anions such as bromide and chloride, out of the water. Deionization systems use tanks full of ion exchange resins to purify potentially contaminated water. The resins bind with any mineral salts in the liquid to separate them from water, so only clean water leaves the tank.

Deionization tanks produce varying levels of purification depending on the resin and the exact type of deionization process, so it’s important to choose the appropriate solution for each particular case.

The following applications require this process for purified water:

• Medical laboratory processes
• Cooling process machinery
• Pharmaceuticals
• Cosmetics
• Electronics manufacturing
• Power plants
• Food processing
• Plating
• Car washes

Deionization can produce three grades of purified water: demineralized (deionized) water, high-purity water, and lab-grade and medical-grade water. Whereas car washes simply need water clean enough to not leave streaks on vehicles, pharmaceutical labs need water with every trace of mineral salts, contaminants, and organic material removed.

Deionized water typically serves as a “perfect” cleaning solvent, an ultra-pure ingredient, and the foundation of a process water recovery/reuse strategy. It is used as an ingredient and a process element in food and beverage processing. As an ingredient, it offers stability, purity and sanitation. As a process element, it is used for effective sanitation.

Deionized water is often mistaken as being the same as distilled water, but this is not the case. Both waters are healthy to drink, but deionized water is even purer. Distilled water conducts electricity whereas deionized water does not.

Contact Reynolds Culligan for More Information

Both deionization and reverse osmosis can greatly help filter out the impurities in water, but each system has its own features and drawbacks. The team at Reynolds Culligan is happy to help you make the best choice. Typically, one can cut operating expenses by using reverse osmosis before a deionized water system. This is called a mixed-bed deionizer. For the purest application, you would use deionized water.

We are capable of delivering both deionization systems and reverse osmosis systems of the highest quality and output. Each system is personalized to the demands of our customers and the water in their location. We work with a tradition and knowledge built up over 70 years of innovation and service.

You can contact us or request a quote today to get a free estimate and free water analysis.