What Is Deionized Water? Is It Drinkable? – WaterFiltersAdvisor

 Last updated  - November 19th, 2021

To understand deionized water, we have to start by understanding ions. Basically, water contains electrically charged molecules or atoms called ions. These ions either have a net positive or negative charge. When it comes to water, ions are often considered impurities, which is why we often look for deionized water, or water that has had the ions removed.

making deionized water

How To Make Deionized Water

During the process of deionization, all the negative and positive ions within water are exchanged for Hydroxide and Hydrogen. There are various technologies and techniques that can be used to make deionized water, depending on the required purity level and the quality of the water source.

The traditional method of deionizing water is to replace impure ions with either hydroxyl ions or hydrogen. However, the water should first be filtered through a reverse osmosis system before deionization. Once the water has been filtered properly, 2 ion-exchange resins are used to exchange the anions and cations for hydroxyl ions and hydrogen, resulting in deionized liquid.

Overall, there are 4 different types of deionizers: automatic units, continuous units, portable exchange tanks, and disposable cartridges. Each system functions on a similar principle, so selecting the right option will depend on the purpose of the water. Further, you can even make deionized water at home!

Making Deionized Water At Home

Home-use water deionization systems are readily available on the market today, with options based on the water use. For example, some systems are specifically designed for car cleaning. These systems are often pretty simple, using 2 chambers filled with negative and positive charged resins to complete the deionization process and remove many dissolved minerals within the water.

What Is Deionized Water Used For?

There are a lot of applications that require the high-purity water that comes from the deionization process. Here are 3 of the top uses:

1. Cooling Applications

Many cooling applications require deionized water because it has a low level of electrical conductivity. By comparison, regular tap water is full of dissolved materials and contaminants, which leads to scale build-up if used for cooling applications. Instead, using deionized liquid prevents scale build-up and allows for a more efficient cooling process.

2. Chemistry And Laboratory Applications

High-purity water is required for sterilization and cleaning lab equipment. Additionally, when water is needed for laboratory and chemistry applications, deionized water should be used. In both of these scenarios, only water with reliably known purity can be used to ensure accurate test results and fully clean equipment.

3. Automotive

Deionized water is also used for washing the surface of vehicles before applying the final paint finish, as it improves both adhesion and surface finish. Additionally, as mentioned before, this water is also used in engine cooling systems to avoid scale build-up and extend the life of the cooling system.

Deionized Water vs Distilled Water

The ideal way to get deionized water is to process normal tap water through a reverse osmosis (RO) system. This process removes all organization materials and any additional contaminants from the water. Finally, after this step, the ions can also be removed to complete the deionization process.

A second option is the distillation process, which is a bit different as it can remove a lot more impurities. By distilling water, you remove most of the bacteria, chemicals, and nearly all minerals. Unlike the reverse osmosis deionization process, where pre-treatment filtering is extremely important, distillation doesn’t require any kind of pre-treatment.

deionized water detailed diagram

Is Deionized Water Safe For Drinking?

Many people wonder whether it’s safe to drink deionized water. Although this water is not poisonous itself, there are multiple reasons why drinking water is not a standard application for deionized water. To start, aside from contaminants, regular tap water has a lot of minerals that can be beneficial, such as the magnesium and calcium. By drinking deionized water, you won’t get any of these beneficial minerals. It’s also important to keep in mind that deionizing water won’t make water potable if it wasn’t safe to drink before. Therefore, it’s better to look for distilled water if you need water to drink.

Final Thoughts

Deionized water has many applications, from laboratory settings to the automotive industry.  There are several ways to deionize water, but it’s crucial to let the water go through a Reverse Osmosis system before the deionization step. And while this water has many uses, it should not be used as a replacement for regular drinking water.