Distilling water purifiers
Distilling is an ancient method where water is heated until it vaporizes and leaves particles, bacteria, minerals, and other substances behind.The steam from the vaporized water cools and condenses into pure water.
Distilled water tastes flat because it has lost its dissolved oxygen. Distilling is not effective against getting rid of chemicals with a lower boiling point than water like ammonia, which is carried over to the condensation chamber, and chloroform, Trihalomethanes, phenol, and trichloroethylene.
Sometimes distilling is combined with other purifying processes such as charcoal to counter these chemicals.Distilling is a slow process, producing only three liters per hour.
A distiller is high maintenance because it needs to be cleaned regularly. It also needs to be placed in an adequately ventilated area because boiling releases many chlorine byproducts.
Charcoal
This type of water purifier uses charcoal to remove the impurities from water before it goes through the tap. The charcoal absorbs the particles and bacteria present in the water.
A charcoal water purifier uses ground charcoal to make it easier for the water to filtrate through the unit. The Environmental Protection Agency rates charcoal water purifiers according to their capability of removing particles as small as one micron or even smaller.
A charcoal water purifier is easy to install, making it very popular among many families.
The charcoal has to be changed only every six to nine months.
Reverse osmosis
Reverse osmosis was originally designed to desalinate seawater but is now largely used for purifying water for industrial purposes. It is a technology adapted from a natural process that separates two liquids of different concentrations using a semi-permeable membrane.
In a home purifying system, the water is forced under pressure against an ultra-fine permeable membrane. The membrane is so fine that it only allows single molecules to pass through and rejects most contaminants. Oxygen is allowed to pass through, so water from reverse osmosis tastes better than distilled water.
However, a typical unit produces water drop by drop, and it needs a pressurized tank to store the produced water. It is rather inefficient because it usually takes five liters of untreated water to produce one liter of clean water. The membrane also has to be replaced every few months by a professional, making it high maintenance.
Ionized
An ionized water purifier runs the water through positive and negative electrodes that separate the minerals and other particles. The purified water is used for drinking, while the rest of the water is used as bath or kitchen water.
An ionized water purifier is known to kill most of the bacteria and particles present in the water. | 
