Evaluation of Nitration/Anammox process by bacterial activity tests.
2015 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
Student thesis
Abstract [en]
Partial Nitritation/Anammox process (deammonification process), by which occurs oxidation of ammonium to nitrogen gas by autotrophic bacteria in anaerobic conditions, considered to be cost-effective and environmentally friendly method of nitrogen removal. Present research work focuses on achieving a high nitrogen removal degree, thanks to Anammox bacteria, while providing the best performance of the ongoing process. Integrated fixed-film activated sludge (IFAS) reactor was supplied with the main stream of the wastewater after UASB reactor, characterized by low concentration of nitrogen and organic matter. The bacteria ability to accommodate, were tested in the biofilm and in the activated sludge, depending on the different stages in which the process were being conducted. Batch test, such as Specific Anammox Activity (SAA), Nitrate Uptake Rate (NUR) and Oxygen Uptake Rate (OUR), were used for the evaluation of activity of various groups of bacteria. On the basis of laboratory analysis verified the values obtained from the batch tests. It was determined that a high degree of nitrogen removal (92% of NH4-N) was achieved thanks to the dominant activity of the Anammox bacteria, with low participation of other groups of bacteria. It was also proved, that Anammox bacteria activity were overwhelming in the biofilm. Dominant role of Ammonium Oxidizing Bacteria (AOB) was associated with high activity of Anammox bacteria, which together satisfyingly out-competed Nitrite Oxidizing Bacteria (NOB) and heterotrophic bacteria. It has been shown that Anammox bacteria quickly adapt to the new conditions and they are able to assume a dominant role, even in the case of inoculation of the reactor with the sludge from SBR. This allows conclude, that in the case of operational problems, the reactor can be supplied from another source, in order not to inhibit the process.
Place, publisher, year, edition, pages
2015.
Series
TRITA-LWR Degree Project, ISSN 1651-064X ; 2015:21
Keywords [en]
Partial Nitritation/Anammox process; Integrated fixed-film acti-vated sludge (IFAS) reactor; Batch tests; Specific Anammox Activity (SAA); Nitrate Uptake Rate (NUR); Oxygen Uptake Rate (OUR); Ammonium Oxi-dizing Bacteria (AOB); Nitrite Oxidizing Bacteria (NOB); Heterotrophic bac-teria
National Category
Civil Engineering
Identifiers
URN: urn:nbn:se:kth:diva-173853OAI: oai:DiVA.org:kth-173853DiVA, id: diva2:855468
Examiners
2015-09-212015-09-212022-06-23Bibliographically approved