How Do Water Filters Work
The question "how do water filters work? is not just an important question for a kid doing a science project. It is also an important question for people who want to acquire water filtration systems for cleaner, safer drinking water in their homes.
Most water filters work basically the same basic way. When water comes in contact with a filtration membrane, contaminants such as bacteria, sediments, and a variety of organic and inorganic compounds are trapped. Filtered water is then passed on to the user.
However, there are some water filtration units that use other technologies such as distillation, ion exchange and reverse osmosis filtration. These systems have certain nuances that a layman consumer should be aware of.
Therefore in answering the question, "how do water filter work? see below for an overview of some of the most popular filtration systems.
Various Water Filtration Technologies
How Do Water Filters Work - Carbon/Charcoal Filters
These filters are the most commonly used household filter because they are economical and can remove a good variety of contaminants. The systems are easy to install and maintain, with filters only needing to be replaced every 6 to 9 months.
These filtration systems are effective at removing bad tastes, odors and chlorine. Generally they don't remove water hardness, toxic heavy metals, micro-organisms and total dissolved solid.
However some carbon filtering devices have been certified to remove additional contaminants such as asbestos, lead and microscopic organisms such as coliform, cysts and giardia.
There are two types of carbon filters - granular activated carbon (GAC)and solid carbon block. Though these systems have their drwbacks, they are still an essential component in many other filtration units such as reverse osmosis and uv purifiers.
Activated carbon has a matrix of millions of microscopic pores that can trap a variety of small and large molecular sized contaminants.
Quality gac filters can remove many gases and polychlorinated biphenyls (PCBs), trichloroethylene (TCE), trihalomethanes (THMs) and volatile organic chemicals (VOCs). The effectiveness of how well these contaminants can be removed depends on various factors such as the duration of filter usage, diameter of the pores, filter design and water flow rate.
Pros - Economical - long life. Eliminates dissolved organics and chlorine effectively. Activated carbon is recognized by the U.S. EPA as the best available technology for filtering VOCs and THMs.
Cons - Can generate carbon fines. Generally won't remove hardness, heavy metals, micro-organisms and total dissolved solids.
How Do Water Filters Work - Reverse Osmosis
You may be familiar with this process in your high school science class. Reverse osmosis filters (ro) work using a similar process.
Water is exposed to hydraulic pressure to a semi permeable membrane with a very fine pore structure. Pure water is separated from the concentrated solution (your tap water).
Because ro filter membranes are highly compact, they produce filtered water very slowly. Storage tanks are used to produce an adequate volume in a reasonable amount of time.
Ro water filters eliminate large amounts of contaminants such as asbestos, lead, some dissolved organics total dissolved solids (TDS), turbidity, asbestos, lead, most heavier-weight VOCs and toxic heavy metals. Even radioactive material can be removed from your tap water.
Pros: - Can remove all varieties of contaminants to some extent. Even more powerful when used in conjunction with carbon filtration.
Cons: - Removes beneficial minerals from drinking water. Produces filtered water at a slow rate. Wastes around 2 to 3 gallons of water for every gallon it produces. Requires extensive maintenance.
How Do Water Filters Work - Ion Exchange Water Filter
The two most popular methods of of ion-exchange methods are softening and deionization.
Water softening is the process that is used to reduce water hardness. Hard water can destroy household appliances and wastes soap. Water softeners contains beads that swap two sodium ions for every calcium or magnesium ion removed from the water.
Deionization beads swap either hydrogen ions for cations or hydroxyl ions for anions. Deionization is a physical process which uses specially-manufactured ion exchange resins which bind to and filter out the mineral salts from water. Because many of drinking water impurities are dissolved salts, deionization produces clean water.
Pros: Is effective at removing inorganics. Fairly inexpensive initial capital outlay.
Cons: Not effective at removing bacteria, organics and particles. Deionizer beds can generate culture bacteria. Long term operation costs are high.
How Do Water Filters Work - Water Distiller
Basically, distillers work by heating water till it vaporizes. Then the vapor is collected in a cooling chamber where it condenses. That water is then used for drinking and cooking.
Distillation removes bacteria and inorganic compounds like calcium, lead, calcium and magnesium.
Unless a distiller is used in conjunction with a carbon filter, it won't remove many organics such as herbicides and pesticides. This is because these contaminants have boiling points lower than water and therefore they are simply transferred into the cooling chamber.
Pros: - Removes the broadest range of drinking water contaminants. Purification capabilities doesn't diminish as fast as other filtration or purification systems.
Cons: - Can take up a lot of counter space. Strips water of healthy minerals. Uses a lot of energy. Distilled water has a flat taste
Check out this quality water distillation system.
What To Do Know
Know that you somewhat can answer the question - "how do water filters work? - get one of these filtration systems for your family today. With all the reports about various harmful contaminants in your drinking water and their potential health hazards - you should take action today.
You now have the chance to protect your family with a quality home water filter.
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