Activated alumina is manufactured from aluminum hydroxide by dehydroxylating it in a way that produces a highly porous material; this material can have a surface area significantly over 200 m²/g.
Activated Alumina is highly porous material, which is very suitable for use as a filter of fluoride, arsenic and selenium in drinking water. Activated alumina filters can easily reduce fluoride levels from 10.0 ppm to less than 1.0 ppm. The amount of fluoride leached from the water being filtered depends on how long the water is actually coming in contact with the alumina filter media. Basically, the more alumina in the filter, the less fluoride will be in the final, filtered water.
Activated alumina is manufactured from aluminum hydroxide by dehydroxylating it in a way that produces a highly porous material; this material can have a surface area significantly over 200 m²/g. The compound is used as a desiccant (to keep things dry by absorbing water from the air) and as a filter of fluoride, arsenic, and selenium in drinking water. It is made of aluminum oxide (alumina; Al2O3), the same chemical substance as sapphire and ruby (but without the impurities that give those gems their color).