Understanding How Water Filtration Works

Basically you have three types of water filters, or more accurately, three types of water filtration methods: mechanical, chemical oxidation reduction (redox) and absorption. Here I have broken down how each one works which will help you choose the water filter that is best for you.

Mechanical Filtration
This is nothing more than having a barrier perforations smaller than the contaminant you want to remove. This process of filtration removes tiny particles that are suspended in the water such as dirt, silt, sand, sediment, rust and additional un-dissolved particles.  As water passes through the media the elements are held or blocked and effectively taken from the water. Nothing too high-tech about that.

Depending on the quality and/or style of the filtration medium, matter as small as 0.5  microns can be taken from your drinking water. For reference purposes, a micron is equal to 1/25,000 of an inch, the diameter of one strand of your hair is about 100 microns.

A variety of substances are used to produce mechanical filtration media. Ceramics and various resins make up the majority of mechanical water filtration.

Oxidation-Reduction Process or Redox
Redox is a process whereby electrons of one molecule are passed on to another. That is to say that where you blend two unlike metals you induce an electrochemical process that oxidizes a host of chemicals frequently found in ground water along with our civic water supplies, consequently taking them out of your water. The heavy metals like lead, chromium, aluminum and cadmium are removed by the electrochemical process. These metals are attracted to the filter’s media, much like to a magnet.

KDF Fluid Treatment, Inc., produces the most widely used media of this kind, a copper and zinc alloy, and has retained the patent ever since 1987.

Adsorption: Activated Carbon
Activated carbon soaks up organic contaminants and substances that can make your water smell and taste bad. Not to mention it has the ability to remove chlorine and its byproducts and pesticides which, of course, are bad for you. This material is very porous having a vast surface area, so much so that the carbon in a common countertop filter could have a surface area of around 200 football fields.

The term “activated” refers to a procedure by which the carbon is made more porous than it is naturally. Activation is achieved with steam, chemicals or by controlled manufacturing processes while creating the carbon.

Activated carbon works like this: When water flows through the filter dissolved chemicals adhere to the carbon letting the water to continue. Essentially this is the same way a sponge works which is why it’s referred to as absorption.

Now that you are clear on how carbon works in a water filter let’s talk about the three categories activated carbon fall into: granulated activated carbon (GAC), carbon block (CB) and powdered activated carbon (PAC). The Carbon Block requires more water pressure but also can remove more contaminants and lasts longer. On the other hand granulated activated carbon is less expensive and is a suitable choice when used with municipally supplied water. The PAC variety is not used in residential applications as often.

Some of the types of material used for manufacturing activated carbon are wood, coal, lignite, coconut shell. Coconut shell is considered the premium choice when making filtration systems for drinking water because of its penchant to enhance the flavor of the water, leaving a “sweetness” to it.

Please understand that water filters do not wholly eliminate contaminates, they can only lessen them. Nevertheless a high-quality filtration system is going to strip the majority of the undesirable contaminants it is designed to remove. Make it a point to buy just water filters certified by the National Sanitation Foundation (NSF). These filters are going to have been tested to verify the manufacturer’s claims. In other words you can be sure of what you are purchasing.

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