AA400G is a granular activated alumina designed for removal of fluoride for potable water situations. It is available in several sizes; although tests show 14 X 28 mesh size is the most suitable for regeneration systems. Fluoride may be found in unacceptable levels (usually above 1.5 ppm) in both naturally occurring water and often in those treated with lime. Activated alumina is the long accepted media of choice for the adsorption of fluoride at the levels normally present. The AA400G is a superior product with good adsorptive capacity and long life.
a. Easy to use: the feed solution is simply pumped through the bed (5 minutes empty bed contact time), to yield an effluent containing less than 1 ppm fluoride.
b. Highly Absorbent: AA400G in lab conditions with high fluoride concentrations can adsorb as much as 1.4 g of fluoride for 100 g of media. Capacity is limited by conditions including competing ions and pH influences. Under the ideal conditions noted a 10 kg unit will keep a stream containing 8 ppm F with a 120 l/h flow rate virtually free of F for six days without fear of break-through.
c. Easy to regenerate: once saturated, the alumina bed can be regenerated by following three simple steps. It is first neutralized with 1% NaOH. Then it’s rinsed with treated water. The final step is reactivation with a 0.05% N H2SO4 solution.
d. Arsenic: Arsenic concentrations, in most applications will also be lowered to acceptable levels.
e. Economical: Because of its high adsorption capacity, an extended run life provides operational cost savings.
Alcan products are being used in large municipal water plants in the U.S., hand pump and domestic units in Asia for fluoride removal.
