Basic Whole House Water Filtration Methods Explained
Whole house water systems use a wide variety of water purification technologies to treat contamination in tap and well water. The most common methods for removing pollutants from the water include carbon adsorption, sediment filtration, ion-exchange, catalytic conversion, oxidation reduction and UV radiation.
In the water industry, activated carbon adsorption is the most commonly used filtration methods for both home and commercial general water purification applications. Activated carbon is created from a variety of carbon-based materials in a high-temperature process that creates a matrix of millions of microscopic pores and crevices. The pores trap microscopic particles and large organic molecules, while the activated surface areas attract and adsorb, small organic molecules. Contaminants that are removed include chlorine, chloramines, chemicals, gases and odors. Through the process of adsorption, these compounds are subsequently diffused into the carbon matrix and are adsorbed or locked into the internal pore structure removing it from the water. Many people are now installing whole house activated carbon systems in their homes to protect themselves from exposure to these unhealthy chemicals which can be absorbed or inhaled during showers or baths.
Whole house sediment filters can remove suspended contaminants such as sand, dirt, silt, scale and organic matter from the water. These materials are most commonly found in well and natural water sources, and they may cause turbidity which makes the water cloudy and unclean. Basic 20” sediment filters use cylindrical cartridges made of paper, polypropylene, string and cellulose to trap suspended water particulates on the surface or within the material of the filter. For heavy-duty residential or commercial sediment removal, a larger backwashing mineral tank system is used. Most modern systems use a natural blend of zeolite which treats turbidity through mechanical straining, sedimentation, ion-exchange and physical & electrostatic absorption. The adsorption properties of zeolite in particular give it an advantage over traditional sediment filters that use sand, sediment and anthracite. Whole house sediment filters will improve the look, feel and taste of your water, and they make excellent pre-filters for carbon and UV filtration systems.
The ion exchange process is another whole house water purification method that is widely used in the home. This term is used to describe the processes of purification, separation and decontamination of ions in water through the use of ion exchange beads. These spherical resin beads are treated with special solutions which allow them exchange positively and/or negatively charged ions with minerals and metals in the water. Water softeners are a popular type of whole house ion exchange filter that removes hard water ions in the form of calcium and magnesium by exchanging with sodium or potassium ions. The benefits of removing these “hardness ions” from the water throughout your home include scale removal protection, softer skin and hair, and cleaner brighter clothes.
Catalytic conversion is a new advancement in water filtration technology that is used to treat water hardness and scale without the use of salt. Unlike traditional water softeners which use ion-exchange to remove calcium and magnesium, salt-free catalytic conversion systems treat the water by changing the properties of these hardness minerals without removing them. When hard water comes into contact with the surface of the catalytic media, calcium and magnesium become attached to the ceramic granules and are converted into a scale resistant crystalline form which will not attach to hard surfaces. Hard water scaling properties are effectively neutralized without the need for sodium, regeneration, or backwashing. These systems are more eco-friendly because they do not require rinse water and electricity, are easier to maintain, and they are 100% salt free making them a healthier alternative to traditional water softening techniques.
Oxidation reduction (Redox) is a water purification method that works based on the principles of electrochemical oxidation, reduction and adsorption actions to remove unwanted contaminants from the water. Redox includes all chemical reactions in which atoms have their oxidation state changed through a transfer of electrons. Iron water filters are a good example of a redox water purification process that removes iron and manganese through the oxidation process. These filters use manganese dioxide which acts as an oxidizer that removes electrons and precipitates iron, hydrogen sulfide and manganese out of the water making it easy to filter them out downstream with a sediment filter. Whole house iron filters can be used to remove iron red stains and rust, manganese brown stains and rotten-egg odors caused by hydrogen sulfide.
Ultraviolet (UV) sterilization is a water disinfection method that uses ultraviolet light to deactivate and eliminate bacteria, viruses and microorganisms. This germicidal irradiation is accomplished by using short-wavelength UV to disrupt and attack microbial DNA eliminating their ability to function and reproduce. Water is purified by running it through a 360 degree stainless steel cylindrical chamber that contains an UV lamp, and microbes in the water are exposed to lethal doses of germicidal UV energy from all sides. This process is extremely effective at eliminating a wide range of bacterial and viral contaminants including e.coli, cryptosporidium, giardia, cysts, coliform bacteria and much more. UV sterilization is also the most natural form of water disinfection as it does not add any chemicals, odors or taste to the water like chlorination does. A whole house UV filter will effectively remove harmful pathogens from your tap and well water to deliver microbially safe water to every faucet in your home.
Whole House Total Solution
The reason there are so many different types of whole house water filters is due to the fact that water quality varies greatly from home to home and no single system can treat all water contaminants. People who want a more comprehensive water filtration solution for their home may need to consider using more than one system to purify their water. A common type of setup would include installing both a whole house filter and a water softener to treat chemicals and hardness in the water. If iron is present, a combination of carbon, manganese dioxide and sediment filtration may be required. Additional UV light systems can be added to treat microbial contaminants in well or tap water.
For drinking water, the process is a bit different as it does not require whole house treatment. Instead, a small undercounter reverse osmosis (RO) system installed under a kitchen sink would be the ideal solution to deliver ultra-pure and safe drinking water. RO systems are a great complement to whole house filters and are often used together to provide a “Total Solution”.