Demineralized Water Vs Distilled Water

Figure 1 Demineralized Water Vs Distilled Water

When considering the optimal drinking water filtration systems, the demineralized water vs. distilled water debate often arises. While both variants are renowned for their purity, they possess distinct characteristics that set them apart. In the realm of drinking water, a popular approach is to combine demineralized and distilled water with essential minerals, thereby crafting a harmonious blend that fulfills the body’s nutritional requirements while delivering a refreshingly clean taste.

In this article, we will introduce you the differences and advantages of Demineralized Water and Distilled Water in detail.

➢What Is Demineralized Water & Distilled Water?

Demineralized water, also termed deionized water, results from the elimination of all mineral ions and other contaminants in water through the utilization of deionized water systems. It typically contains no dissolved minerals or impurities and has a total dissolved solids (TDS) value of close to zero. This makes it an excellent choice for many applications, including medical, laboratory, and industrial use.

Distilled water is a kind of pure water, which is pure and clean after water treatment, and does not contain impurities or bacteria. As pure water, it does not contain any impurities. It is mostly used in biopharmaceuticals, the cosmetics industry, and industrial distilled water. The common ways to prepare distilled water include electrodialysis method, ion exchanger method, reverse osmosis method, distillation method, and so on. Industrial distilled water is generally obtained by distilled water method.

➢How are Demineralized Water and Distilled Water Produced?

In the procedure of creating demineralized water, the task includes eliminating every mineral ion from the water using a technique known as ion exchange. It works by passing the water through an ion exchange resin that contains ions that are attracted to the mineral ions in the water. The resin exchanges these ions, effectively removing the minerals from the water. The result is water that is free from all minerals and has a neutral pH.

When the raw water is boiled and then evaporated and condensed to recover, it is a common distillation method in the laboratory to separate and purify the liquid mixture. But the way of evaporating comes with some disadvantages, such as bringing evaporable harmful substances into the condensed distilled water. Therefore, it is necessary to purify water through secondary and tertiary distillation methods. But this process requires a lot of heat energy and cost input.

➢Demineralized Water Vs Distilled Water: What’s the Difference?

Figure 2 Distinctions between demineralized water and distilled water

The main distinctions between demineralized water and distilled water stem from the methods used to purify them and the degree to which minerals are eliminated.

*Purification Method

  1. Demineralized Water: People commonly abbreviate demineralized water as “DM water,” and purification methods such as ion exchange or reverse osmosis are used to purify it. Utilizing industrial reverse osmosis systems these methods target the removal of ions and minerals from the water, leaving it with a lower conductivity and reduced mineral content.
  2. Distilled Water: Distilled water is obtained through the process of distillation. This involves heating the water to its boiling point, capturing the resulting steam, and then condensing it back into liquid form. The impurities and minerals are left behind during this process, resulting in highly purified water.

*Mineral Content

  1. Demineralized Water: While demineralized water undergoes significant mineral removal, it might still retain trace amounts of minerals and impurities due to the limitations of the purification methods used. The mineral content is generally lower than that of tap water but not as negligible as in distilled water.
  2. Distilled Water: Distilled water is characterized by its exceptionally low mineral content. The distillation process effectively separates water molecules from minerals, resulting in water that is nearly free from ions, metals, and other impurities.

*Applications

  1. Demineralized Water: Demineralized water finds use in various industrial applications where low levels of minerals are required to prevent scale formation and maintain equipment efficiency. It is commonly used in laboratories, manufacturing processes, and battery production.
  2. Distilled Water: Distilled water is utilized in applications demanding the highest level of purity, such as in medical and pharmaceutical industries, automotive batteries, and steam irons. It’s also commonly used in laboratory experiments where any trace of impurity could affect results.

Figure 3 Distilled Water

*Conductivity

  1. Demineralized Water: Demineralized water typically exhibits a higher electrical conductivity compared to distilled water due to the presence of residual ions and minerals.
  2. Distilled Water: Distilled water has very low electrical conductivity owing to its minimal mineral content. This property makes it ideal for use in applications requiring a lack of electrical conductivity.

*Taste and Odor

  1. Demineralized Water: Demineralized water might retain a slightly “flat” taste due to the absence of some minerals that contribute to flavor in natural water sources.
  2. Distilled Water: Distilled water is often described as having a neutral taste and odor since most of the minerals responsible for imparting taste and smell are removed during the distillation process.

While both demineralized water and distilled water are forms of purified water, they are obtained through different processes and have varying levels of mineral content. Demineralized water retains some minerals, whereas distilled water is almost entirely free from minerals, making it suitable for applications requiring the highest degree of purity.

➢How to Demineralize Water?

Demineralized water is water from which minerals have been extracted, and it finds utility in various contexts, including industrial procedures, laboratory trials, and medical establishments. Let’s delve into how to demineralize water using a demineralized water plant.

Figure 4 Quantity of Demineralized Water

*Step 1: Determine the Required Quantity of Demineralized Water

Before starting the demineralization process, it’s essential to know the required quantity of demineralized water, as this will determine the type of equipment and the process that will be utilized. Depending on the application, the quantity of water required might vary considerably, so it’s crucial to have this information beforehand.

*Step 2: Select the Appropriate Demineralization Technology

The market offers various demineralization systems like reverse osmosis, distillation, and ion exchange. Each demineralization machine has a different capacity, efficiency, and cost, so it’s crucial to select the one that meets the needs and budget. Reverse osmosis is the most common demineralization technology, and it uses a semi-permeable membrane to remove ions and minerals from water.

*Step 3: Install the Demineralized Water Plant

Once the technology has been selected, it’s time to install the demineralized water plant. The installation process might involve several steps such as connecting pipes, electrical outlets, and control panels. If necessary, seek professional assistance and follow the manufacturer’s instructions. The plant should be placed in a dry and clean area that is easily accessible to facilitate maintenance and operation.

Figure 5 Demineralized Water Plant

*Step 4: Start the Demineralization Process

After the installation of the plant, it’s time to start the demineralization process. The process might involve several stages such as pre-treatment, membrane filtration, and post-treatment. Each stage has different parameters that need to be monitored such as flow rate, pressure, and conductivity. The demineralization process might take several hours or days, depending on the plant’s capacity and the quality of the feedwater.

*Step 5: Test the Demineralized Water Quality

After the demineralization process is completed, it’s crucial to test the quality of the demineralized water. The water quality should be tested for parameters such as pH, conductivity, total dissolved solids, and microbial contamination. The quality of the demineralized water should meet the required standards, and it should be suitable for the intended application.

➢Reasons to Use Demineralized Water Instead of Distilled Water in Industries.

Figure 6 Demineralized Water in Industries

  1. Demineralized water has a low conductivity rating, making it ideal for use in processes that require precise control of electrical current. This is especially useful for electronic manufacturing and other industrial applications.
  2. The lack of impurities in demineralized water makes it excellent for medical or laboratory work as well as in the food industry.
  3. Demineralized water has no calcium or magnesium present, therefore reducing the risk of scale build-up in pipes and fittings, which can cause substantial damage to equipment and processes.
  4. The lower cost of demineralized water makes it an attractive option for industries where budget is a significant concern.
  5. Demineralized water can be recycled more efficiently than distilled water, making it a more sustainable option.
  6. The presence of free oxygen is beneficial to specific processes in industrial applications, due to the ability of oxygen to react with other molecules and accelerate chemical reactions.
  7. Demineralized water has a long shelf life compared to distilled water, which needs to be replaced much more frequently. 

It’s important to note that demineralized water still contains trace amounts of minerals, and thus its use may be limited in certain applications where absolute purity is required. In these cases, distilled water is the better choice. Yet, demineralized water provides numerous benefits compared to distilled water in the majority of industrial applications. It’s important to weigh up all the pros and cons before deciding on which type of water to use for your needs. 

➢FAQs.

1. What is the difference between deionized water vs demineralized water?

Deionized water and demineralized water are terms often used interchangeably, but they slightly differ. Both are purified water forms with removed minerals, achieved through processes like ion exchange. Deionized water primarily targets the removal of ionized salts, whereas demineralized water also eliminates minerals that are not ionized. In practice, the terms are often used synonymously due to their similar results.

2. Does demineralized water have an equivalence to distilled water?

Distilled water and demineralized water exhibit similarities, yet they differ. Demineralized water has minerals removed using processes like ion exchange, while distilled water is created by vaporizing water and condensing the steam, leaving impurities behind. Both produce purified water but through different methods.

Figure 7 Distilled water and demineralized water

3. Is distilled water demineralized?

Although distilled water and demineralized water share similarities, they are not identical. Indeed, distilled water constitutes a variant of demineralized water. The method of distillation, which entails vaporizing and subsequently condensing water, eliminates minerals and impurities. Consequently, this yields a variety of demineralized water.

➢Bottom Line.

Demineralized water retains certain levels of minerals while distilled water is completely void of any minerals whatsoever. Therefore, each type of water has its unique benefits and drawbacks. Depending on your specific needs, you may find that either one will serve you best.  If you are looking for a water treatment plant for the demineralization of potable water then consider NEWater products– they have commercial reverse osmosis systems to produce high-quality demineralized waters with superior chemical characteristics compared to conventional demineralization plants.

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