House Water Filters: A Piece Explaining The Media Employeed And How It Works
Basically there are three types of water filtration, or more correctly, three styles of water filtration methods. They are mechanical, chemical oxidation reduction (redox) and absorption. Next is a description of how each works.
Mechanical Filtering
This is simply having a barrier that has perforations smaller than what it is that you intend to remove. This process of filtration removes minute elements that are floating in the water like dirt, silt, sand, sediment, rust and additional un-dissolved substances. As water flows through the media the substances are trapped or inhibited and for practical purposes removed from the water.
Depending on the class and/or kind of the filtering media, particulates as tiny as 0.5 microns are able to be stripped from your drinking water. For the purpose of reference, a micron is equal to 1/25,000 of an inch, the diameter of one filament of your hair is around 100 microns.
A variety of substances are used to manufacture mechanical filtering media. Ceramics and a variety of resins comprise the greater part of this kind of water filtration.
Oxidation-Reduction or Redox Process
Redox is a process in which electrons of one atom gets passed on to another. What this means is that if you mix two dissimilar metals you get an electrochemical process that oxidizes a multitude of chemicals regularly discovered in ground water in addition to our public water stores, and as a result eliminating them from the water. The heavy metals such as aluminum, cadmium, lead and chromium are removed by the electrochemical process. Metals such as these are attracted to the filter’s media, much like to a magnet.
KDF Fluid Treatment, Inc., makes the most extensively used media of this nature, a coper and zinc mixture, and has retained the patent ever since 1987.
Adsorption: Activated Carbon
Activated charcoal soaks up organic elements that may make your water stink and taste awful. Also it has the ability to get rid of pesticides, chlorine and its byproducts. This material is extremely porous having a immense surface area, to the extent that the carbon in an average countertop filter could have a surface area of about 200 football fields.
The term “activated” refers to a process by which the carbon is made more porous than it would be on its own. The activation process is effected by using steam, a chemical process or by controlled production processes while creating the carbon.
Here is an explanation of how activated carbon works: As water flows through the filter dissolved chemicals attach themselves to the carbon allowing the water to keep going. This process is known as absorption.
Activated carbon will fall into one of three categories: carbon block (CB), granulated activated carbon (GAC) and powdered activated carbon (PAC). The CB category works better at higher pressures, where the granulated activated carbon costs less and performs well with public water supplies. The PAC kind is not use residentially as often.
Some of the types of material used for manufacturing activated carbon are coal, wood, lignite, coconut shell and such. Coconut shell is thought of as the ideal material when creating filters for drinking water due to its propensity to make the water taste better.
Be advised that water filters do not totally get rid of contaminates, filters will just lessen them. However a superior water filter will remove nearly all of the undesirable contaminants it is designed to eliminate. Make it a point to get only water filtration systems certified by the National Sanitation Foundation (NSF) These filters will have been tested to verify the manufacturer’s claims. Therefore you will know what you are buying.
August 30, 2009 - 9:50 PM Comments: Closed