Partial Nitritation of Swine Wastewater in View of Its Coupling with the Anammox Process
- Albert Magrí *,
- Matias B. Vanotti,
- Ariel A. Szögi and
- Keri B. Cantrell
Partial nitritation (PN) of swine wastewater was investigated in a sequencing batch reactor (SBR) using a high-performance nitrifying sludge. Characteristics of the wastewater used were low content of biodegradable organic matter and a high alkalinity-to-ammonium ratio. The target oxidation of ammonium nitrogen (NH4+–N) to nitrite nitrogen (NO2−–N) was 57% (1.32 g NO2−–N g–1 NH4+–N), which corresponds with the reaction ratio of the anaerobic ammonium oxidation (anammox). This target was successfully achieved at 32°C by controlling the inflow rate and the corresponding nitrogen loading rate (NLR). An average NLR of 1.47 g NH4+–N L−1 d−1 was applied to the partial nitritation sequencing batch reactor during a period of 70 d. The nitrite production rate obtained was 0.91 g NO2−–N L−1 d−1. No nitrate was produced. The PN effluent contained 1.38 g NO2−–N g−1 NH4+–N, which was within 5% of the target ratio. Under steady composition of the wastewater, the pH was shown to be a good indicator of the PN process performance. Furthermore, in a second sequencing batch reactor, the anaerobic ammonium oxidation process was effectively applied to the PN effluent, attaining a nitrogen conversion rate of 0.36 g N L−1 d−1 (14.3 mg N g−1 volatile suspended solids h−1).Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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