Simultaneous NH3 oxidation and N2 production at reduced O2 tensions by sewage sludge subcultured with chemolithotrophic medium |
| |
Authors: | E B Muller A H Stouthamer H W van Verseveld |
| |
Institution: | (1) Department of Microbiology; Biological Laboratory, Vrije Universiteit, De Boelelaan 1087, 1081 HV Amsterdam, The Netherlands |
| |
Abstract: | The ammonia oxidation rate by sewage sludge was determined as a function of the dissolved oxygen tension. Samples of sludge were taken from a domestic waste water treatment pilot plant in which sludge was completely retained by membrane filtration. The samples were subcultured chemolithotrophically in recycling reactors. The gas supplied was a mixture of pure argon and oxygen. The K
O2 for ammonia oxidation was estimated to be 0.97 (±0.16) kPa dissolved oxygen. Together with ammonia oxidation and oxygen consumption, dinitrogen gas was produced. So, aerobic denitrification occurred. At dissolved oxygen tensions of 1.25 kPa and higher, the dinitrogen production rate (per N-mole) equalled 20% of the ammonia oxidation rate. This proportion was even 58% at 0.3 kPa dissolved oxygen. At 0.15 kPa dissolved oxygen, however, nitrification hardly proceeded, while dinitrogen production soon stopped. Most likely, a nitrifier concomitantly oxidized ammonia and reduced nitrite to dinitrogen. |
| |
Keywords: | chemolithotrophic nitrification denitrification oxygen limitation activated sludge wastewater treatment recycling reactor |
本文献已被 SpringerLink 等数据库收录! |
|