Buy Deionised Water? Why Distilled water is better than Deionised Water

How is Distilled Water different from Deionised Water?

Water purity is essential across various industries and applications, leading to the development of multiple purification methods. Two commonly used types of purified water are Distilled water and Deionised water. While both undergo processes to remove impurities, they differ significantly in production methods, purity levels, and suitable applications. Understanding these differences is crucial for selecting the appropriate type of water for your needs. The principal differences between Distilled water and Deionised water are in their production methods. Deionisation is considered a much inferior practice to distilling water. Deionisation, also known as demineralisation, uses ion-exchange resins to remove mineral ions from water. The process involves passing water through resin beads that exchange unwanted cations (such as calcium and magnesium) and anions (such as chloride and sulfate) with hydrogen and hydroxide ions, respectively. This exchange results in the formation of pure water. However, deionisation primarily targets ionic impurities and may not effectively remove uncharged organic molecules and will not remove bacteria, or viruses.

During the process, the ion-exchange resins undergo a process during which the purer ions that have been fixed to the beads are released while the impure ions that are lighter are driven upwards an on to the beads that are later removed from the tank. These deionisation beads will exchange hydrogen and/or hydroxyl ions for cations or for anions. The deionisation process is generally carried out as a component of total water purification albeit an important one.

Deonisation is known to be exceptionally efficient, although the process can struggle to remove most forms of organic bacteria or micro-organisms. In the process it is not unusual for micro-organisms to attach themselves to the resins in the tank, actually exacerbating the growth of bacteria.

Conversely the process of distilling water involves some form of evaporation process where water from a feed tank is brought to boiling point and the steam that gathers is harnessed in a separate tank allowed to cool back to liquid form. This is a relatively simple process, and does not involve the introduction of any materials into the water as is the case with deonisation.

Purity Levels and Contaminant Removal

Distilled Water

The distillation process removes a comprehensive range of contaminants, including:

• Dissolved Salts and Minerals: Substances like sodium, calcium, and magnesium are left behind during boiling.
• Organic Compounds: Many organic impurities have boiling points higher than water and are thus separated during distillation.
• Microorganisms: Bacteria and viruses are typically eliminated due to the high temperatures involved in boiling.

Deionised Water

Deionisation effectively removes most mineral ions but has limitations:

Limited Organic Contaminant Removal: Deionisation does not effectively remove uncharged organic molecules, bacteria, or viruses.
Potential for Microbial Growth: The ion-exchange resins can become breeding grounds for bacteria if not properly maintained, potentially introducing contaminants into the water.

Due to its high purity, distilled water is suitable for applications requiring minimal impurities:

Laboratory Use: Essential for experiments where contaminants could interfere with results.

Medical Equipment: Used in devices like CPAP machines to prevent mineral buildup.

Automotive Systems: Ideal for cooling systems and lead-acid batteries to prevent corrosion.

Cosmetic Products: Ensures product stability and safety by minimising contaminants.

Advantages of Distilled Water Over Deionised Water

1. Comprehensive Contaminant Removal: Distillation effectively removes a broader range of impurities, including non-ionic substances, organic compounds, and microorganisms, ensuring higher purity.

2. Microbiological Safety: The high temperatures used in distillation kill bacteria and viruses, reducing the risk of microbial contamination. In contrast, deionisation does not remove these pathogens and may even promote bacterial growth on resin surfaces if not properly managed.

3. Consistency and Reliability: Distillation provides consistent water quality, as the process is less susceptible to fluctuations in feed water composition. Deionisation efficiency can vary depending on the resin condition and the presence of organic contaminants, potentially affecting water quality.

4. Longer Shelf Life: Distilled water is less prone to recontamination during storage, making it more suitable for applications requiring longer-term storage without compromising purity.

5. Versatility: The high purity of our distilled water makes it suitable for a wider range of applications, including those requiring the absence of both ionic and organic impurities.