A water filtration unit is a unit or machine designed to extract impurities and chemicals from water. There are many different types and sizes of water filtration units. A water pitcher with a small filter kept in the fridge is considered to be a water filtration unit, while a whole house system that filters all water that enters a dwelling is also one. An industrial water filtration unit designed to remove heavy metals and chemicals is bigger, more complicated water filtration unit. These units operate differently, but each has a common purpose: to purify water.
Charcoal carbon filters make up approximately 95% of water filtration units purchased for residential use. The charcoal used in the filter is usually derived either from a coconut husk or a block of honeycombed carbon. Sometimes, a form of charcoal called silver impregnated charcoal is used. Each of these charcoals have positive ions that attract contaminants and chemicals with negative ions. The contaminates and chemicals, including Crypstosporidium and Giardia, are trapped and absorbed.
Most charcoal filters are able to effectively filter out contaminants for between six and nine months before losing their effectiveness. If there is too much sediment in the water, the charcoal filter may not be able to filter it all out or the filters may become clogged after a shorter time. In some cases, a sediment filter is added to ensure the charcoal filter remains effective and to ensure ensure proper filtration. The charcoal and sediment filters both allow healthy minerals to pass through.
Industrial water filtration units do not use charcoal, as home units do. This type of water filtration unit usually uses sand or walnut shells to capture large impurities, such as heavy metals, oil, and other chemicals. Sand and walnut shells can filter larger amounts of water in less time than charcoal filters. Sand and walnut shells are also less costly to purchase in large quantities than charcoal. An agitator may be used to ensure that all the water comes into contact with the sand or shells, helping to ensure that more contaminants are removed.
A good industrial water filter, when combined with an agitator, can remove more than 90% of all chemicals and contaminants that are larger than five microns in size. Large industrial water filtration units can filter between 100 and 12,000 gallons of water per minute. The appropriate size filter depends on the amount of water purification necessary.