With a bone char filter from US Water Systems, you’ll enjoy clean, healthy water without any added fluoride. Bone char is an affordable, highly effective way of removing fluoride from water, and it can also remove a number of toxic metals. While this material is similar to – and contains some portion of – activated carbon, it has a different molecular structure that makes it better at removing different contaminants from water.
To put it simply, bone char is animal bones (usually cow bones) that have been carefully selected, cleaned, aged, and heated to over 1, 200°F to produce a form of charcoal. Scientifically, it is made up mostly of tricalcium phosphate, a natural calcium salt found in bones and milk; smaller amounts of calcium carbonate, also called calcite, chalk, or marble; and activated carbon. Calcite and activated carbon are both used separately as water filters, and they do contribute to some of the filtering abilities of a bone char filter.
A bone char water filter is effective at removing fluoride because of the tricalcium phosphate. The form found in bone charcoal is actually called hydroxyapatite, which includes a hydroxide ion. Because of the way that the molecule is structured, this ion is easily replaced by fluoride. To put it simply, when water that contains fluoride is exposed to the bone char, the fluoride ions are swapped for the hydroxide ions and removed. This treatment is very effective, often removing 90% of fluoride from water.
Carbon from wood and animal sources has been used for centuries as a medical treatment, and there is some indication that it was used to purify water as early as 450 BC. The specific adsorptive powers of charcoal were studied scientifically in the second half of the 18th century, and by the early 19th century, researchers discovered that bone char was very effective as a decolorizing agent. It was quickly adopted by the sugar refining industry, which spurred more research into new ways to regenerate this form of charcoal and to create a granulated form.
Bone char has been used to remove fluoride from water since the 1940s, and it was widely used in many parts of the United States for this purpose for much of the 20th century. While this method is less common than it once was, using a bone char filter is still an affordable and effective treatment. Fluoride can also be removed from water with a reverse osmosis system.
In addition to removing fluoride from water, bone char filters have been shown to remove a number of metals, including copper and cadmium, as well as arsenic and lead. The material has been used to remove radioactive particles and trihalomethanes (THMs) as well. While these filters are typically not used primarily for this purpose, it is an added benefit.