Water purification isn’t essentially a complex process. However, two common ways of achieving purity in water – demineralization and distillation – are different in some ways. Considering demineralized water Vs. Distilled water comparison will expose some similarities and differences between the two water purification processes.
Generally, you can remove water impurities through both demineralization and distillation. However, distillation gives a purer product compared to demineralization. The exchange of minerals and the removal of organic contaminants are the central basis of the differences between demineralization and distillation.
This article will help you understand what demineralized and distilled water is. You’ll know their similarities and differences and understand how to get each of them. You’ll also see where each type of pure water is applicable.
What is Demineralized Water?
Water contains atoms of chemicals, including some minerals such as calcium, magnesium, potassium, chlorine, and many more. Generally, chemical charges other than hydrogen and hydroxyl ions are considered impurities and need to be removed from the water. Demineralization is one way to achieve that.
Demineralization is the process of achieving water purification by exchanging mineral ions present in the impure water for hydrogen and hydroxyl ions present in a resin. Simple ion exchange, where positively charged ions, such as sodium, magnesium, potassium, and other metals, are exchanged for negatively charged hydroxyl ions and negatively charged minerals. Chlorine is exchanged for positively charged hydrogen ions to form pure water.
Therefore, demineralized water, also called deionized water, is a form of pure water that has undergone positive and negative mineral ion exchange for hydrogen and hydroxyl ions. However, it may contain traces of some dissolved minerals and organic compounds.
How do you demineralize water?
Demineralizing water involves using two types of resins in two different chambers to acquire pure and deionized water. Ion exchange occurs in these chambers until the resins are incapable of exchanging ions and regenerating. Therefore, to demineralize or deionize water, you’ll need:
- Two resins – a cation and an anion exchange resin.
- Two demineralization chambers
- Raw water
- Regenerative chemicals – Hydrochloric acid (HCl) and Sodium hydroxide (NaOH).
- A collecting bowl
The process:
- Fill each demineralization chamber with resin. The cation resin is in one chamber, and the anion resin is in another chamber. Note that the chambers are connected.
- Pass raw water into the first chamber containing the cation exchange resin. It passes from this chamber into the next, containing the anion exchange resin.
- Collect the demineralized water in a collecting bowl.
While this is an easy process, the action that takes place during this process is called ion exchange. When the raw water goes into the first chamber, the positively charged ions (captions) that it contains are exchanged for hydrogen ions that are present in the resin. The hydrogenated water passes into the second chamber, exchanging its negatively charged ions (anions) for hydroxyl ions. Pure, demineralized water is collected into the bowl or tank.
See our Ion Exchange Softener Reviews
What is Distilled Water?
Distilled water is a form of pure water that is without mineral and organic impurities. It is considered a more refined form of water than deionized or demineralized water. Distilled water is obtained by subjecting the water to high temperatures so that it changes into its gaseous state and, on cooling, returns to its liquid form without the mineral and organic impurities.
Distilled water is a result of water purification through distillation, one of the simplest forms of water purification. Impurities from inorganic sources, such as metallic cations, heavy metals, anions, and organic sources, are removed during the evaporation of water molecules. On condensation, only hydrogen and hydroxyl ions are left.
How do you distill water?
Water distillation is one of the easiest ways to purify water and can be done for various types of water. To distill water, you’ll need:
- A source of heat
- Raw water
- A condensation tube, such as the Liebig condenser.
- A collecting bowl or tank
The process:
- Fill a bowl with raw water and set heat beneath it.
- Cover the bowl with a condenser, or attach a condenser to the bowl’s cover.
- As the water boils, steam rises into the condenser and cools to form water again.
- Collect the condensed water into a bowl or tank.
As simple as the process seems, you may need to set up the apparatuses to reach your water purification goal effectively. It is common to assume that boiling water with a lid over the container distills water, but it doesn’t. The condensed steam returns to the heating water, which may still contain some impurities.
The actions that take place during the process include heating, evaporation, cooling, condensation, and collection. The heated water becomes energized, and ions are set free, causing impurities to break into their respective chemical make-up. On evaporation, volatile compounds escape into the atmosphere, while hydrogen and hydroxyl ions recombine in the condenser, where the temperature is cooler, to form pure water. The water is then collected in a bowl or tank.
Is demineralized water the same as distilled water?
Demineralized and distilled water are not the same, although they are both pure water forms. They have some similarities, but they are different. The general differentiating feature of demineralized and distilled water is their product pureness. However, there are other differences. You can distinguish demineralized water from distilled water through:
The process of purification
Demineralized water and distilled water achieve water purity through different processes. While they both involve the removal of impurities and extraneous compounds in raw water, they do so using other means.
Demineralized water comes about through demineralization, a process involving cations exchanging only hydrogen ions and anions for hydroxyl ions. On the other hand, distilled water is obtained from a combination of boiling, evaporation, and condensation of water molecules to form pure water. Though their products are pure, they reach their goal through different means.
The pureness of the result
While demineralized and distilled water are considered pure, they have different degrees of pureness. Demineralized water has removed every ion in a water sample and replaced it with hydrogen and hydroxyl ions. That means testing the said water sample will contain only water molecules and no other compounds, hence its purity. However, demineralization doesn’t remove heavy metals, such as arsenic, from water samples.
Distilled water, on the other hand, doesn’t exchange ions; it removes all molecules by heating them to their boiling point. Molecules with lower boiling points leave the water before it boils, and once the water molecules reach their boiling point, they evaporate, and other compounds with a higher boiling point are left behind. On condensation, only the water molecules are present in the condenser, and they’ve collected in the tank or bowl.
Distilled water is purer than demineralized water, without heavy metals and other organic substances.
The items and apparatus needed for purifying water
During water purification, it is easy to differentiate between the distillation and demineralization processes. Generally, the demineralization apparatus setup is more sophisticated and costlier than the distillation setup.
While demineralization uses chambers, resins, and acids, distillation requires heat and a condenser.
Taste
Generally, pure water has no taste, but you may be able to differentiate demineralized water from distilled water by taste, provided the former has some heavy metals. This difference isn’t expected; you won’t find it in demineralized water you buy in stores as they may also go through other forms of water purification. However, you may taste some metals in the water sample if they don’t.
Distilled water has no taste whatsoever. It’s without metallic or salty taste, as long as its integrity is preserved after purification.
Why choose one over the other?
There are many applications for demineralized water and distilled water. However, some industries choose one over the other, while others use both water purification methods to ensure a hundred percent pure water.
Power turbines in power stations, distilleries, food and beverage production, and laboratories, among others, claim to use demineralized water. Still, they have to distill demineralized water to remove organic substances such as viruses and bacteria. Also, they need to demineralize distilled water to remove dissolved gases such as carbon dioxide.
Reasons for choosing either distilled or demineralized water
Personal preference
Your choice of pure water – demineralized or distilled – can be due to some bias. Some individuals prefer the more worldly things to the regular ones. Demineralized water goes through a process foreign to many people; hence, some individuals find that to be reason enough to choose it. However, others choose distilled water because it is a more straightforward process that they understand.
Ease of accomplishment
A more complex process costs more, while a simpler one may come cheaper. Distilled water is simple and common; hence, distilled water from stores is more affordable than demineralized water. Also, because distillation is reasonably straightforward, individuals may choose to do it at home using a distilling unit instead of purchasing water from a store.
Affordability
Simple is affordable, making distilled water a pure water of choice. However, because distilled water may contain dissolved gases, it may be unsuitable for some industries, but humans can consume it.
Demineralized water is devoid of dissolved solids but can contain viruses and bacteria, which may be detrimental to humans. This makes it reasonable for further purification processes, such as nanofiltration and reverse osmosis, to remove the organic substances. These processes cause added production costs and make demineralized water less affordable.
Health reasons
Because we’re sure distilled water has no viruses or bacteria, we believe it is better for our health. However, it contains some dissolved gases. Demineralized water is also pure and poses no risks, such as developing cholera or waterborne diseases.
However, distilled water and demineralized water deprive you of some minerals, which, in the long run, causes mineral deficiencies.
Importance of distilled water and demineralized water
The importance of distilled and demineralized water is found in the necessity for pure water for our livelihood as humans. It transcends the satisfaction of our personal bias towards consuming the cool stuff but contributes to many aspects of our lives. The importance of distilled water and demineralized water is found in:
Cleaning apparatuses
Laboratories in the medical, biosciences and food industries need super clean apparatuses to get the right results from their experiments and tests. To make their devices clean, they clean them with distilled or demineralized water. In many cases, they prefer demineralized water that has undergone other filtration processes to remove organic and inorganic impurities in the water.
Generating power
Power plants that use power turbines are powered by steam produced at high pressures. Although the use of steam to power turbines points to the use of distillation, they usually distill demineralized water to make the steam the turbine needs.
Demineralized water contains no dissolved gases or solids, and distillation removes organic impurities and produces the needed steam.
Producing drinks
Distilleries require soft water to produce beers and other drinks. However, distillation doesn’t provide water soft enough to ensure the safe operation of their machines. Therefore, demineralized water is distilled to create the softest water they can use.
Maintaining good health
Demineralized and distilled water is essential for maintaining good health as they contain no impurities that may cause imbalances in our body chemistry. However, there are concerns about mineral deficiencies, but they can be addressed by consuming more mineral supplements.
Where to Get Demineralized and Distilled Water
All types of pure water – including demineralized and distilled water – are available in any store you walk into. However, it is pertinent that you ensure that your country’s water quality agency approves the brand of demineralized and distilled water you’re purchasing.
Your local registered pharmacy is a more reliable place to see distilled and demineralized water.
Conclusion
Demineralized water is obtained through ion exchange, leaving only hydrogen and hydroxyl ions after passing through resins. Distilled water is obtained from evaporation and condensation processes. While both types of water are pure, you can achieve perfectly pure water by combining both water purification methods.
Distilled and demineralized water is helpful in food and beverage production, laboratories, power generation, and maintaining good health.
