DI-tech Activated Alumina, Fluoride & Arsenic Removal Media
- DI-tech Activated Alumina is a pre-conditioned (acidified) granular aluminum oxide used for residential and industrial feed waters to reduce arsenic and fluoride levels.
- DI-tech Activated Alumina receives a special acid washing treatment to lower the internal pH of the raw media. Both arsenic and fluoride removal are negatively impacted by high pH. DI-tech Activated Alumina is based on a raw product that is NSF-61 listed and represents a BAT (Best Available Technology) by the US EPA.
DI-tech Specialty Media for Fluoride and Arsenic Removal NSF Certified
Activated Alumina Pre-Conditioned for Higher Selectivity
DI-tech Activated Alumina is a pre-conditioned (acidified) granular aluminum oxide used for residential and industrial feed waters to reduce arsenic and fluoride levels. DI-tech Activated Alumina receives a special acid washing treatment to lower the internal pH of the raw media. Both arsenic and fluoride removal are negatively impacted by high pH. DI-tech Activated Alumina is based on a raw product that is NSF-61 listed and represents a BAT (Best Available Technology) by the US EPA.
Physical and Chemical Properties
|Media Structure:||Acidified Granular Aluminum Oxide media.|
|Functional Groups||Oxide (hydroxyl)|
|Ionic Form as Shipped||Slightly Cationic|
|Physical Form||White grains|
|Total Capacity||1.5-2.0% by weight|
|Screen Size Distribution:||14x28 Tyler Mesh 16-30 US Standard|
|Uniformity Coefficient||1.3 (max)|
|Surface Area||380 m2/gm|
|pH Range Stability||5-9 operating|
|Temperature Range||40-180oF (5-80oC)|
|Shipping Weight:||40 lbs per cubic foot|
|Packaging||28.32 liter (1 cu ft) boxes 5 cu ft fiber drums|
|Also Available||28x48 (30-50 mesh)|
DI-tech Activated Alumina is a frequently used media in municipal water treatment for the removal of arsenic and fluoride. It is listed by the US EPA as a BAT for these uses. As a raw product, activated alumina contains Na2O (sodium oxide) which converts to NaOH (sodium hydroxide) in water producing a very high pH and rendering its capacity to near zero. Regeneration is with caustic and acid so the media must be pre-conditioned before use unless the user has the ability to handle those harsh chemicals. DI-tech Activated Alumina is listed as NSF-61 for safety.
Regeneration and Pre-Treatment
DI-tech Activated Alumina can be field regenerated using first, a dilute solution of NaOH to strip the arsenic and fluoride. The media is then rinsed with feed water and the neutralized with a dilute solution of H2SO4 or HCl followed by a full rinse with clean water. Regeneration details are available from Systematix Co.
Optimizing with Pre-Treatment
Activated alumina capacity reduced by high pH (above 8.2) and bi-carbonate alkalinity (above 50 ppm) in the feed water. In such cases, pre-treating the feed water with a salt regenerated strong base anion (SBA) resin (a dealkalizer) will both reduce the pH AND the alkalinity. In addition, SBA resin has a modest capacity to reduce the arsenic and fluoride content of the feed stream, prolonging the capacity and life of the alumina polisher.
Optimal flow conditions in use are 1.5-2.5 gpm/cu ft of media. Higher flows with minimal retention time will reduce capacity and increase average leakage. Backwashing is done at 10 gpm/sq. ft. for 10 minutes every 4-7 days.
A single family home might use 120,000 gallons of water/year…about 1 million pounds. Capacity of 1.5% means a cu ft. (40 lbs) of AA can remove 0.6 lbs of contaminant. At 1.2 ppm of fluoride, this is about 50,000 gallons.
A material safety data sheet is available for DI-tech Activated Alumina. Copies can be obtained from Systematix Company (fax 714-522-5443). DI-tech Activated Alumina is not a hazardous product and is not WHMIS controlled.