Denitrification inhibition by high nitrate wastes

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:82789

Veydovec, W; Silverstein, J ^[1]; Cook, Jr, N E; Figueroa, L A ^[2]; Hund, R ^[3]; Lehmkuhl, G D ^[4]

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1. Univ. of Colorado, Boulder, CO (United States). Dept. of Civil, Environmental, and Architectural Engineering
2. Colorado School of Mines, Golden, CO (United States). Dept. of Environmental Science and Engineering
3. American Water Works Association Research Foundation, Denver, CO (United States)
4. EG and G-Rocky Flats, Golden, CO (United States)

The processing of radioactive metal products at nuclear weapons plants and research labs has produced wastewaters containing high concentrations of nitrate, often greater than 50,000 mg/l N. The adaptation of activated sludge and inhibition of denitrification at high nitrate concentrations was studied using pH controlled bench-scale sequencing batch reactors (SBRs), operated with 50% of the SBR volume recycled (recycle volume = influent volume). Denitrification of 1,350 and 2,700 mg/l NO{sub 3}{sup {minus}}-N was completed after approximately 5 hours and 15 hours, respectively. No denitrification of 5,400 mg/l NO{sub 3}{sup {minus}}-N was observed. These results suggest that there is a progressive inhibition of denitrification as nitrate concentrations increase from 1,350 to 5,400 mg/l NO{sub 3}{sup {minus}}-N. In a subsequent series of experiments at an initial reactor nitrate concentration of 1,350 mg/l N, a significant accumulation of nitrate was observed, resulting once in destabilization with loss of denitrification and once in successful adaptation of the activated sludge. At a nitrate concentration of 1,350 mg/l N, the adaptation of activated sludge appears to be unstable, resulting sometimes in stable denitrification and sometimes in biomass washout.

• OSTI ID: 82789
• Report Number(s): CONF-940789--; ISBN 0-7844-0031-8
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
DENITRIFICATION
ECOLOGICAL CONCENTRATION
NITRATES
NUCLEAR FACILITIES
RADIOACTIVE WASTE PROCESSING
WASTE WATER