Arsenic Chemistry
Arsenic Species
As (III) – H3AsO3, H2AsO3-1, HAsO3-2
As (V) – H3AsO4, HAsO4-1, AsO4-2
What is the significance of Arsenic speciation?
As (V) is more effectively removed than As (III) but this is the case by most of the Adsorbents.
Arsenic Occurrence
Most of the surface waters as they get enough oxygen the Arsenic is predominantly As (V)
Lack of oxygen in Ground waters are usually found with As (III). But some times they can be as As (V) or a combination of both As (III) and As (V).
Here are the table of the products that can address the Arsenic removal for industrial or municipal application:
Media name |
Media composition |
Removal process |
Dependency |
Estimated media replacement |
High content MnO2 coated ZEOSORB |
adsorption with precipitated iron hydroxide |
Iron in the inlet water* (min. x20 times the As conc.) |
in 7-10 years |
|
Feroxyhyte coated GAC |
absorption |
Best recommendation pH 6.5 - 6.9 |
in 2-5 years (regenerable) |
|
Titanium dioxide based adsorbent |
adsorption (highest loading capacity) |
Best recommendation pH 6.5 - 6.9 (to avoid silica interference) |
in 8-18 months (depending on contaminants) |
|
Iron hydroxide based adsorbent |
adsorption |
Best recommendation pH 6.5 - 6.9 |
in 8-18 months (depending on contaminants) |