Clean Water through the Distillation Process
Distillation can be defined as separation of one substance from another by evaporation and condensation. For water, this method separates liquid from undesired contaminants; the obtained product or distillate is pure water without unwanted chemicals, heavy metals, odor, and microorganisms.
How Water Distillation Works
The process works by heating water to its boiling points. All contaminants that have lower boiling points are collected and discarded. Other pollutants that have higher boiling points will remain in a container; these too will be discarded. After reaching its boiling point, water evaporates creating steam. When the temperature cools down, steam condenses back into water. As a result, the water produced by condensation has higher purity than the initial liquid before evaporation.
A water distiller has various parts including a boiler and condenser. Water is boiled in a closed container called a boiler. Vapors created from the surface of boiled water travel through a pipe to a vessel called a condenser. In the simplest form a condenser is a tube surrounded by another larger tube filled with cold water. Vapors only travel in the smaller tube and they will not come into contact with cold water in the larger tube. The main function of cold water is to help cool down the temperature to a point where vapor can condense back into liquid form. As vapor loses heat and becomes liquid, it travels into a collecting vessel. The process continues until all source water in the boiler has evaporated. The entire apparatus is typically called a “still”.
In many respects the process is similar to the natural purification method. Water from the ground or sea evaporates due to heat produced by the sun, and vapors turn into liquid form as precipitation as the temperature cools down. The biggest difference is that in a still, the liquid form does not have to come into contact with other contaminants in the air or river before you drink it.
Is It Safe to Drink Distilled Water?
Yes, it is usually safe to drink distilled water but it all depends on the source water. If you take water from an industrial source, the water probably contains extremely high amount of contaminants, meaning the distilled water may still have considerable trace amounts of pollutants. You may need to distill it for few times until it is safe for human consumption. Spring water, rainwater, and river water are good sources for distillation. Impurities are possibly introduced to water by its container or distillation equipment. Contaminants can leach out of tubing, glassware, and even plastic from bottles. It is more common to purify the water through a filtration process and then distill it.
Combined Purification Methods
VOCs (Volatile Organic Compounds) are also concerns in the water distillation process. They are airborne contaminants introduced to air by many household items including but not limited to aerosol spray products, adhesive removers, hair spray, perfumes, refrigerators, dehumidifiers, and air fresheners. Tap water contains none or nearly no VOCs; it they indeed exist, they are undetectable during the distillation cycle. To make sure you remove all contaminants including VOCs from drinking water, water filtration using active carbon prior or post distillation can remove up to 99% of impurities. A water distiller can be used virtually forever without changing any parts, yet it provides consistent purity. It does require power for boiling, but it is available in electric and non-electric versions depending on heat source you use. With filtration system, it is necessary to replace the filters regularly. However you can often use a water filtration process that does not require electricity. The approach using a combination of these two purification methods removes heavy metals, inorganic and organic elements, and microorganisms.
- Tap water from non-industrial source is heated to 212° F (100° C, the boiling point of water), killing microorganisms such as viruses, cysts, and bacteria.
- Water evaporates and leaves dead contaminants behind including dissolved solids, heavy metals, and microbes.
- Contaminants that have low boiling points (those that evaporate before water does) are collected and discharged through gaseous vents.
- Condensation occurs.
- Through coconut shell carbon filtering medium, water flows through to the faucet.
- Pure water comes out and collected in a container.
Some contaminants have lower boiling points than water, while others have higher boiling points. Waterwise water distillers provide a different purification method for each type, as described in step 2 and 3. During the evaporation phase, VOCs are carried along into the condenser because they are airborne. Normally you will need separate purification equipment that has active carbon filter to get rid of those pollutants. All Waterwise water distillers have built-in filters located after condenser and before faucet, meaning the water that comes out to your glass or bottle has been filtered as well. Such water distillers produce higher purity level compared to either distillation or filtration method alone. Unlike the Reverse Osmosis purification method, gradual clogging can be avoided because the filter only works for distilled water. The company also offers a model which filters source water prior to distillation.