Delta’s AAFS50 Activated Alumina Water Treatment Products combine chemisorption, physisorption, and particulate (or physical) filtration to remove metal contaminants from water.  Because it offers various kinds of adsorptive sites and has lots of surface area, activated alumina adsorbs minerals in water better than most other materials. Its efficiency at removing zinc, lead, phosphates, copper, arsenic, and high levels of fluoride has been proven, and it can remove silica, mercury, selenium, and chromium.