Water Purification Methods

The following is a summary (in non-technical language) of the most common technologies used.

Carbon Filtration

Carbon filters are considered the most efficient and the most effective filters for removing the worst contaminants in municipal water. This water purification method utilizes a process called adsorption, which is where particles stick to the surface of the carbon material.

These filters are usually made of powdered block carbon or granular activated carbon (GAC). Activated carbon has a slight electro-positive charge to it. The negative ions of the contaminants are thus more attracted to the positive charge of the activated carbon.

Both types of carbon filters are effective, but there seems to be ongoing debate about which one is more effective.

Some of the water contaminants that carbon filters remove include chlorine, chloramines, trihalomethanes, radon, benzene, dissolved volatile organic chemicals (VOCs) such as herbicides and pesticides, as well as hundreds of other man-made chemicals found in our water supplies.

Carbon filters also remove bad tastes and odors and will reduce the amount of hydrogen sulfide as well as sediment in the water. However, carbon filters are not very effective for removing heavy metals.

These filters are cost effective but require frequent filter changes and reduced water flow for optimum filtration.

Kinetic Degradation Fluxion (KDF)

The KDF filter uses a copper-zinc formulation and a chemical process known as oxidation reduction (or redox), which works by exchanging electrons with contaminants.

This water purification method is often used in conjunction with other technologies for overall effectiveness of the water system.

The KDF method is especially effective with the more advanced water filters, such as the Kangen Water™ system, which uses electrolysis to produce mineral-rich ionized water.

One of the key benefits of KDF filters is that they remove heavy metals such as lead and mercury. This is one of the reasons why they combine so well with carbon filters, since carbon filters are not that effective at filtering heavy metals.

KDF filters are also effective for removing chlorine, iron and hydrogen sulfide, as well as certain bacteria, viruses and fungi.

Distillation

Water distillers boil water to collect the steam, leaving behind many contaminants. The steam is then returned to its water form in a purified state. This water purification method is effective for removing bacteria and most minerals.

However, most distillers do not remove VOCs, chlorine and chlorine by-products. In addition, distillers de-mineralize the water, making it unhealthy to drink.

The other major disadvantage with distillers is that they are highly inefficient, wasting approximately five gallons for every gallon of water that is filtered.

In addition, the distillation method is expensive because it takes a lot of time and energy to heat the water. Typically it can take up to four hours to produce one gallon of water.

Reverse Osmosis

The reverse osmosis (RO) water purification method involves forcing water through a semi-permeable membrane. The membrane filters out minerals such as salt, lead, manganese, iron and calcium, as well as certain chemicals.

While this process is effective at reducing an array of water contaminants, especially fluoride, it does not remove all chlorine and chlorine by-products as well as volatile organic chemicals (VOCs), pharmaceuticals and a wide array of man-made chemicals.

In addition, like distillation, the process removes naturally occurring minerals in the water that are essential to health, such as calcium and magnesium.

From my personal and professional experience, I believe drinking de-mineralized water is unhealthy. For this reason, I do not recommend water filters that use reverse osmosis or distillation as a water purification method.

In addition to the health disadvantages, reverse osmosis filters waste three gallons of water for every gallon they filter. This is certainly not a good way to help protect our world water supply.

Ultraviolet (UV) Treatment

The ultraviolet water purification method is highly effective at killing bacteria, viruses, molds, algae, and other micro-organisms including Cryptosporidium and Giardia, two of the most common causes of waterborne illness.

However, because UV systems do not remove most chemical contaminants or sediment, they are not considered effective for drinking-water systems.

This technology is often only used in whole-house water filtration systems and in combination with other technologies.

The good news about the UV method is that some municipal water treatment plants are starting to experiment with using ultraviolet treatment in place of chlorination for disinfection.

Many experts believe UV treatment is just as effective as chlorine for killing bacteria and other pathogens. UV treated water is certainly healthier than chlorinated water.

Particulate or Mechanical Filtration

Particulate filters screen out large particles from water, such as sand, sediment, some bacteria and unhealthy microbes.

These filters are also called mechanical, or micro, filters and are often used in conjunction with other technologies.

Particulate filters are used most effectively as a pre-filter in a multi-step, water-filtration system.

Ion Exchange Water Softeners

This water purification method involves passing water through an ion exchange unit in which hard metal ions are replaced by softer sodium ions.

Thus, the technology is effective for making the water feel softer and for preventing mineral deposits from collecting in plumbing and fixtures.

However, used alone this method is not adequate as a water purification method for drinking water. It is often used in combination with reverse osmosis, carbon filtration and electrolysis water filters.


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