D891 (Cl form) resin is highly nitrate selective due to its unique functional group. In fact, it is a product designed to be much more selective to nitrate or perchlorate than our standard nitrate selective resin, D890. Both D891 and D890 have higher affinity for monovalent anions (e.g., nitrate) than for di– or tri-valent anions. This is the opposite of the standard Type I and Type II anion resins such as A307 and A302.
Because of its unique nature, D891 reverses the electro-selectivity of standard anion resins, and offers preferential removal of anions of lower
valence. Particularly, the product can be highly effective in the removal of nitrate and/or perchlorate in water and wastewater treatment applications even with the presence of high sulfates, carbonates and bicarbonates.