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The Population Dynamics of Nitrifiers in Ammonium‐Rich Systems
Author(s) -
Raszka Anna,
SurmaczGórska Joanna,
Żabczyński Sebastian,
Miksch Korneliusz
Publication year - 2011
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143011x12989211841331
Subject(s) - nitrification , nitrobacter , ammonium , nitrifying bacteria , activated sludge , environmental chemistry , population , nitrite , chemistry , anammox , bioreactor , denitrification , ecology , environmental engineering , biology , sewage treatment , environmental science , nitrogen , denitrifying bacteria , nitrate , organic chemistry , demography , sociology
Non‐optimal pH, dissolved oxygen concentration, the presence of toxic substances, or the influence of grazers are known to cause disturbances in nitrification. Because activated sludge is a mixture of different organisms, bacteria, and higher organisms, the stability of processes such as carbon removal, nitrification, denitrification, and dephosphatation depends on a range of interactions. These interactions occur both between and within trophic levels. Understanding of the ecology of microorganisms involved in bioprocesses is essential for effective control of startup and operation of a particular process. The aim of the study was to gain further insight into the dynamics of nitrifiers in activated sludge at various sludge ages while treating higher concentrations of ammonium. The results confirmed the importance of Nitrosococcus mobilis and Nitrobacter sp. as the dominant nitrifiers responsible for nitritation and nitratation, respectively, in the presence of unlimited ammonium. The size of the dominant bacteria colony was larger compared to the other species present and reached 25 µm. Problems with nitrification occurred in all high‐ammonium loaded reactors. The dynamics of nitrifier population was monitored by oxygen uptake rate (OUR) using a test enabling the OUR measurement separately for ammonium‐oxidizing bacteria (AOB) and nitrite‐oxidizing bacteria (NOB). The results reveal the hypersensitivity of nitrifiers to the substrate and products of incomplete nitrification.