This study evaluated the feasibility of replacing acetic acid with a commercial carbohydrate-based electron donor (CBED) for removal of nitrate and perchlorate (ClO4-) from drinking water. Bench-scale biologically active carbon fixed-bed and fluidized-bed reactors (FXBR and FLBR, respectively), with an initial empty bed contact time (EBCT) of 42.8 min, were fed simulated groundwater containing 15 mg/L nitrate as nitrogen and 200 µg/L ClO4-. EBCT in the FLBR after final expansion was 80.5 min. During the first 100 days using acetic acid at 125 mg/L chemical oxygen demand (COD), complete nitrate removal was achieved in both systems, whereas perchlorate in the FXBR and FLBR effluents remained below 3 and 6 µg/L ClO4-, respectively. For comparable removals, influent COD requirement was higher with the CBED. Biomass yields with acetic acid and the CBED were 0.54 to 0.58 and 0.59 to 0.74 mg CODbiomass/mg CODsubstrate, respectively. The higher yield with the CBED resulted in more frequent maintenance requirements.
Upadhyaya, G., Kotlarz, N., Togna, P., Raskin, L.
Published In:
Journal American Water Works Association
December 2015
http://www.awwa.org/publications/journal-awwa/abstract/articleid/5362138...
Upadhyaya, G., Kotlarz, N., Togna, P., Raskin, L., "Carbohydrate-Based Electron Donor for Biological Nitrate and Perchlorate Removal From Drinking Water." Journal of the American Water Works Association. 107 (12), pp: E674-E684, December 2015.