What are ions?
Ions are electrically charged atoms or molecules that are found in water. They either have a net positive charge or negative charge. Ions are a substance that are naturally present in water, so putting water through a deionisation process is a way of producing pure water. When measuring ions, electrical currents pass through water and uses ions as stepping stones. The less ions in the water, the more difficult it would be for electrical currents to pass through, therefore the more deionised or pure the water is.
What is the process of making deionised water?
Explaining this process can become quite complicated, especially when using chemical terminology that most people aren’t familiar with, so in a nutshell this process is called ion-exchange. The way it works is through a mixed bed system where the ions in the conventional water attach themselves to resin beads that also either have a negative or positive charge.
Demineralisation therefore requires using at least two types of ion exchange resins to produce deionised water. One resin will remove positively charged ions and the other will remove negatively charged ions. These beads interact with the respective ions and are either exchanged with hydrogen (H+) or hydroxyl (OH-) depending on the charge, and the combination of hydrogen (H+) and hydroxyl (OH-) forms pure H20.
What are the types of water?
Type I
Type I grade water, also known as Ultrapure water, is the purest form of water you can get. It has been purified to the highest specifications, and contains only pure H20, as well as a balanced number of H+ and OH- ions. This type of water is mainly used in the pharmaceutical industry, as well as the semiconductor industries which are an essential component of electronic devices, enabling advances in communications, computing, healthcare, military systems, transportation, clean energy, and countless other applications.
Type II
Type II grade water still has very high levels of purity and can be useful in various laboratory practices, such as feed water because there is less calcium build up that can occur. It can also be used for microbiological analysis and preparation, as well as electrochemistry and more.
Type III
Type III grade water, also known as RO water is produced through a purification process known as Reverse Osmosis. RO is a technology that is used to remove a large majority of contaminants from water by pushing the water under pressure through a semi-permeable membrane. This water has the lowest level of purity, but is usually the starting point for basic laboratory practices, such as cleaning glassware or other equipment.
Uses and Applications for Deionised Water
Laboratory Tests
Getting accurate results are essential when doing lab tests, and using ordinary water may compromise the results due to the unwanted contaminants. Using deionised water will ensure a far more accurate result. It is used to perform in experiments, as well as cleaning the equipment.
Product Formulations
Using deionised water as part of product formulations can make the world of a difference, as there is no risk of those unwanted particles in ordinary water reacting with your formulation. The purer the water, the more accurate your results will be. This can include any formulations regarding cosmetics, hair care, body care, cleaning products and more.
Aquariums and Fish Tanks
In order for marine life to have the ideal habitat in their tanks, it is imperative that you use deionised water as it will improve their overall health and lifespan. Using regular water is considered impure and may result in excess algae build up.
Cooling Systems
Deionised water is used in cooling systems due to its low conductivity which allows devices to maintain a certain temperature level without overheating and therefore causing less damage to the device. It is also especially useful on medical devices.
Fire Extinguishers
Deionised water is used in fire extinguishers due to its low electrical conductivity. Unlike ordinary water, this causes less damage to electrical equipment and is overall a lot safer when putting out a fire.
Industrial Machinery
Machinery needs to be cleaned on a regular basis in order to avoid excess build up and grime. Using ordinary water to clean or operate a machine may cause it to corrode faster, which then defeats the point of cleaning it so often because you are adding unwanted contaminants, which in turn makes the machine corrode faster. Using deionised water is ideal for this because there are no contaminants that will cause exacerbated corrosion, therefore making your equipment last a whole lot longer.
This can also apply to car engines as well.
Water Purity Standards
There are a couple of organisations that can be used for water purity standardisation, however at Brightpack we will be measuring our deionised water against the ISO (International Organisation for Standardisation) Standards.
There are certain parameters that the water gets measured against:
pH Value
pH measures the concentration of hydrogen ions in the water - a pH level of above 7.0 is alkaline and below 7.0 is acidic, however these parameters only apply to the least pure classification of water (type III or below) because Ultrapure water does not have any dissolved content in order for it to have a pH level.
Conductivity
Conductivity tells us how much dissolved content that could conduct electricity, is still present in the water. This is different to resistivity, however is measured similarly. If water is highly conductive, then it is not very resistant to an electrical current. Conductivity is measured in mS/m (millieSiemens per meter)
Total Dissolved Solids (TDS)
Total dissolved solids (TDS) are the amount of organic and inorganic materials, such as metals, minerals, salts, and ions, dissolved in a particular volume of water - basically it is a measurement of anything that is not an H20 molecule. The common types of dissolved solids that may be present in ordinary water are Calcium, Chloride, Magnesium, Potassium, Zinc, Aluminium, Copper, Lead, Arsenic, Iron, Chlorine, Sodium, Fluoride, Bicarbonates, Sulphates, Pesticides, and Herbicides.
ISO Specifications
The following table illustrates the purity specifications of each grade:
Brightpack Deionised Water Purity
At Brightpack, we make our very own deionised water - this is achieved through a seven stage filtration system by means of a mixed-bed resin deionisation filter. With this seven stage system, it removes 99.9% of the above mentioned dissolved solids.
The characteristics of our water is as follows:
PH – > 5 and < 7
TDS - < 5 ppm
Electrical Conductivity – 0,01 mS/m
