Not all Arsenic removal medias are alike.
The ISOLUX® Zirconium Technology Is Truly Unique.
The patented Zirconium Hydroxide adsorption media sets ISOLUX® shoulders above all other arsenic treatment technologies. Until now, you might not have heard of it, but Zirconium has been used for decades worldwide for arsenic removal.
ISOLUX® Zirconium media is the only arsenic removal media in the industry in powder form. Powder has much more surface area than the typical granules. Zirconium powder media gives ISOLUX® the ability to pull up virtually all the arsenic in a water stream in less than 30 seconds versus 3 to 5 minutes with granular medias. This fast uptake is precisely what makes the unique, no-backwashing, ISOLUX® cartridge technology possible.
- Unparalleled non-breakable, non-leachable arsenic bond.
- Verified for virtually non-detect (zero) arsenic removal.*
- Removes both AsIII and AsV, simultaneously, without pretreatment, chemicals or chlorination.
- Media NSF 61 certified for drinking water use
- Imparts no odor, taste or color to water.
- Media bed residence time 27 seconds.
* Due to variances in influent water quality, users are urged to perform independent verification of the non-hazardous character of spent media cartridges. Additionally, some states may have disposal criteria different from Federal guidelines (TCLP).
Points of Clarification:
1. Other Arsenic Removal Technologies
We have not reviewed reverse osmosis or resin media for the following reasons:
- High capital cost
- High levels of maintenance
- Waste of 1/3 to ½ of process water
- Discharge of reject water with high levels of arsenic
- System capital cost
- System complexity
- Discharge of a brine regenerations stream with
- Very high levels of arsenic
Adsorption media systems are the preferred arsenic removal method for small to medium sized water treatment systems.
2. Regarding Safe Landfill Disposal of Spent Arsenic Removal Medias
Every supplier of arsenic removal systems states that their spent media product is non-hazardous as it passes TCLP (Toxicity Characteristic Leaching Procedure) tests. Since TCLP tests are standardly run at a pH value of 4.5, every adsorption media will pass. The arsenic –laden media can then be disposed of at landfills classified for handling non-hazardous materials.
However, research at the University of Arizona has demonstrated conclusively that granular iron medias loaded with arsenic will leach it, under landfill conditions at hazardous (ppm) concentrations.
The issue with the current test for arsenic is that it uses an extractant solution with a pH of approximately 4.5. At this pH, arsenic is very tightly bound to iron, and therefore, a minimum of the arsenic is released into the extractant solution. Unfortunately, the pH conditions that exist in such landfills are quite different, with the pH ranging from 7 to 9 typically. At such pH, the binding power of iron for arsenic is greatly reduced. Chemically reducing conditions in landfills also convert the iron to a more soluble form, causing further separation of the arsenic from the iron. This means that a material classified as safe for disposal in a non-hazardous landfill can potentially leach arsenic into the surrounding landfill at concentrations that are above the hazardous level.
Modifying the TLCP procedure to one more representative of environmental conditions existing in the landfills would be a first step toward correct classification of such medias. Once this is done, arsenic-laden media of this type would then likely be more correctly classified as hazardous and would have to be disposed of in landfills that can accept such hazardous waste. This creates a dilemma for users as the higher cost for disposing of the media as hazardous waste must ultimately be passed on to consumers.