AWWA JAW64229

Chlorite is the dominant degradation byproduct of chlorine dioxide reactions. Compliance with the maximum concentration of 700 µg/L established by new Italian regulations for drinking water can be achieved by reducing chlorine dioxide dosage during water treatment or by removing chlorite. This work investigated granular activated carbon (GAC) as a technology for chlorite removal. Research focused specifically on the interference between chlorite and organic matter removal on GAC active sites and the applicability of a "chemical regeneration" process to improve GAC removal efficiency for organic matter and chlorite. Batch and column tests were performed on both distilled water and surface water spiked with chlorite, virgin, exhausted, and thermally regenerated carbon provided by a surface water treatment plant, and exhausted GAC after chemical regeneration by means of acid, base, and base-acid solutions. Results demonstrated that GAC can be an efficient method for chlorite removal. Includes 12 references, tables, figures.