Water Nuggets Practice Exam 2025 - Free Practice Questions and Study Guide

The most efficient process for the removal of nitrate and nitrite is anion exchange. This method specifically targets negatively charged ions, which includes nitrate (\(NO_3^-\)) and nitrite (\(NO_2^-\)).

Anion exchange resins contain positively charged functional groups that attract and hold onto negatively charged anions. When water containing nitrate and nitrite flows through the anion exchange medium, those ions are exchanged for other anions, typically hydroxide ions. This process is highly effective because it not only removes these harmful contaminants but can also be fine-tuned to regenerate the resin, allowing for multiple uses and enhancing cost-effectiveness.

In contrast, other methods like cation exchange primarily focus on positively charged ions, making them unsuitable for removing nitrate and nitrite. Powered activated carbon and granular activated carbon, while effective for various organic compounds and some inorganic pollutants, do not have the same level of efficiency when it comes to targeting specific anionic contaminants like nitrates and nitrites. Thus, anion exchange emerges as the specialized choice for effectively addressing these particular pollutants.