Deionized water is a highly purified water with its mineral ions removed, such as cations from sodium, calcium, iron, copper, and anions such as chloride and bromide. Deionization is a physical process that uses specially manufactured ion-exchange resins, which bind to and filter out the mineral salts from water. Because deionized water is free from impurities, it is used to clean machinery and equipment in many industrial and commercial settings to clean machinery and equipment.

The two main types of deionization are:

Co-flow deionization – In co-flow deionization, the raw water flows in the same direction as the regenerant flows.

Counterflow deionization – The raw water flows in the opposite direction in counter-flow deionization.

Many of us use deionized water daily in our home water purification systems. It makes an excellent alternative to distilled water for automotive batteries. Many people drink deionized or distilled water because it tastes better than tap water supplied by municipal authorities. However, both types of water have a pH level of around six and contain no essential minerals or trace elements, so they should not be consumed over extended periods without supplementation.

Deionization is a common way to purify water. The process can remove virtually all dissolved minerals from the water, giving it a much higher electrical resistivity than tap or spring water. The difference between deionized and distilled water is that deionized water undergoes an extra step in purification to remove even more impurities than distilled water. Deionized water can be used in power generation, automotive manufacturing, and healthcare because it won’t leave any mineral deposits behind after evaporation.

All water contains some dissolved minerals, mainly sodium and calcium ions. These can be removed through distillation or reverse osmosis, but both methods leave a mix of positively and negatively charged molecules behind, which continue to conduct electricity.

In the deionization process, an ion-exchange resin or molecular sieve consists of tiny beads (2–3 mm diameter) usually made of an organic polymer substrate. These beads are treated with a strong acid to convert them to the hydrogen form. The beads attract various cations, but only hydrogen (H+) and hydroxyl (OH−) ions are strongly attracted.

The main difference between conventional ion exchange and deionization is that you need to regenerate the resins in traditional ion exchange by rinsing them with sulfuric acid and sodium hydroxide, which means that you cannot use it for pure drinking water.

Benefits of deionized water

1. Deionized water is also commonly used as a laboratory solvent for preparing HPLC (high-performance liquid chromatography) samples, PCR (polymerase chain reaction) samples, cell culture media, and other solutions.
2. Deionized (DI) water is commonly used in the creation of biofuels. The conversion process from plants and other organic waste products into biofuels such as ethanol and biodiesel.
3. Its ability to dissolve into ions makes it ideal for conducting electricity.
4. It is used in specimen processing where surgical instruments are clean. Deionized water is used in conjunction with a liquid or gas disinfectant and a microbial-free rinse to ensure that the instruments are free of any residuals, guaranteeing absolute sterility.
5. Deionized water is used to create distilled water used in automobile batteries and humidifiers.
6. Deionized water is used in the cleaning of electronic components and circuit boards.
7. Deionized water is used to measure the conductivity of solutions
8. It’s often used in car washes, where it’s sprayed onto the car’s surface and then allowed to dry without being rinsed off. This leaves the car looking shiny and clean because the deionizing process removes dirt and leaves no mineral deposits behind.

Downsides to using deionized water

The downsides of using deionized water are also apparent. It cannot flush out impurities in equipment to act as a solvent. Other downsides include;

• Hardness: Deionized water is soft, so it can cause plumbing and fixtures to degrade over time. It also leaches minerals from your body, making your skin dry.
• pH: Deionized water is acidic. That’s why some people use deionization with alkalization systems to make their water safe for drinking.
• Bacterial contamination: Because there are no minerals in deionized water, it doesn’t inhibit bacterial growth as hard water does. You’ll need to take additional steps to purify your water if you want to drink it or use it for food preparation.
• Unpotable for drinking: Deionized water isn’t drinkable and can be harmful to humans. When people drink demineralized water, it leaches minerals from their bodies because it seeks to equalize itself with bodily fluids. It also removes beneficial minerals from food when you cook with it.