There are many misconceptions about what filtered water is. Is it safe to drink? Is it healthy? To clear all doubts, here's a simple definition for filtered water. Filtered water is simply municipal tap water that has been run through carbon filters that remove the chlorine content from the treated water, thereby improving taste. A micron filter can sometimes be used as well in place of carbon filters. After the filtration process is complete, the water is subsequently ozonized and bottled. Filtered water is what you find bottled in grocery stores.
Most tap water has differing levels of a lingering disgusting residual chlorine taste that makes many people detest drinking tap water. Now, this is where filtration comes in. Filtration is the process of removing bacteria, pesticides, and chemicals like chlorine from water to purify the water. There are different types of water filters and water filtration systems – some filter types can filter almost anything, while others may be specific to certain contaminants. The filter you choose will depend on your needs and budget.
Importance of Filtered Water
Certain organisms, bacteria, elements, and chemicals found in water are known to cause more harm than good to the human body. Tap water in certain areas is not safe for consumption. It can make one ill either from an infection or from the accumulation of toxic contaminants such as heavy metals and pesticides. Filtered water is also beneficial because it removes specific repulsive tastes (such as the taste impacted by chlorine), thereby improving the general acceptance of the water. In the long run, it is cheaper to have a water filtration system at home than buying bottled water for drinking and cooking.
So, now that we've cleared the air on what filtered water is and why it is important to filter our water, let's consider the different types of water filtration.
Types Of Water Filtration
There are several approaches to water filtration, but the six common filtration types and processes in treatment systems are:
- Activated Carbon Filtration
- Reverse Osmosis
- Aeration Filtration
- Cation Exchange Filtration
- UV Disinfection
1. Activated Carbon Filtration
This filtration process is the most common type of filtration that employs the use of relatively inexpensive carbon filters. In this filtration system, activated carbon attracts and absorbs particles in water as the water runs through a filtering screen impregnated with carbon. This filtration process removes heavy metals, chemicals, parasites, radon, pesticides, and MTBE if present in the water. Activated carbon filters are commonly used in point-of-use devices such as pitchers and under-sink or faucet-mounted units.
2. Reverse Osmosis
This filtration process is one of the most effective water filtration systems and is typically employed in point-of-use devices. Reverse osmosis, however, may be more expensive than some other filtration systems. In this filtration system, pressure forces water through a semi-permeable membrane that removes practically all contaminants.
Although this filtration method eliminates more pathogens and chemicals than other methods, its downsides remain cost and water wastage. For example, for every 3.7 liters (1 gallon) of filtered water produced, about 15 liters of water (4 gallons) will get thrown out. If you have a compromised immune system or want the cleanest water for consumption, this filtration method remains the best option.
3. Aeration Filtration
This filtration process forces water into the homes as high-pressure air jets. Therefore, contaminants that quickly become gases, e.g., fuel byproducts or radon, will evaporate. However, other contaminants like heavy metals (e.g., mercury) and parasites may remain in the water. This type of filtration system may be employed at the point of entry systems and for water samples that are known to have the concentration of heavy metals and pesticides within the acceptable range.
4. Cation exchange
This filtration process attracts and traps positively charged ions such as magnesium, calcium, and barium by the use of negatively charged particles within the exchange resin. As the water passes over the beads in the exchange resin, the particles responsible for the hardness of water (calcium and magnesium) are trapped. Consequently, the water becomes "soft". Calcium and magnesium do not have health risks, but they can damage pipes in the home. Barium, however, can be a health concern.
This process remains one of the best and easiest ways to remove heavy metals and pathogens from water. Distillation involves the boiling of water and the condensation of the resultant steam back into the water. During this process, the water becomes free of bacteria, viruses, and pulling contaminants such as mercury, lead, and arsenic because these substances can not evaporate. Distillation is often employed in point-of-entry systems or countertop devices.
6. UV Disinfection
This process destroys bacteria, viruses, and parasites using ultraviolet light. However, UV disinfection does not remove contaminants such as metals or chemicals from water. It often used in point-of-use under-sink systems.
To wrap it all up, we can conclude that filtered water is simply water that has undergone some processes that frees it from certain types of contaminants, such as PFAS, that have been in the spotlight for being a widespread issue in the US water supply.