Nitrifying Communities in Biological Nitrogen Removal Processes at Tropical Municipal Wastewater Treatment Plants
Liang Feng1, Jia Xing Loi1, Joana Séneca2,3
1Sustainable Process Engineering Center, Department of Chemical Engineering, Faculty of Engineering, Universiti Malaya.
Abstract:
Nitrifying communities in activated sludge play a crucial role in biological nitrogen removal processes in municipal wastewater treatment plants. While extensive research has been conducted in temperate regions, limited information is available on nitrifiers in tropical regions. The present study investigated all currently known nitrifying communities in two full-scale municipal wastewater treatment plants in Malaysia operated under low-dissolved oxygen (DO) (0.2-0.7 mg DO L-1) or high-DO (2.0-5.5 mg DO L-1) conditions at 30°C. The core nitrifiers in the municipal wastewater treatment plants were Nitrosomonas (ammonia-oxidizing bacteria, AOB), Nitrospira (nitrite-oxidizing or complete ammonia-oxidizing, comammox, bacteria), and ammonia-oxidizing archaea (AOA) as identified by a 16S rRNA gene amplicon sequencing ana-lysis and corroborated by 16S rRNA-targeted fluorescence in situ hybridization. A quantitative polymerase chain reaction (qPCR) targeting ammonia monooxygenase subunit A (amoA) genes revealed stable populations of comammox Nitrospira and AOB in both wastewater treatment plants. AOA were detected in only one of the plants and their population sizes fluctuated, with higher temporary abundance under high-DO conditions. These results provide important insights into the composition and dynamics of nitrifying communities in tropical municipal wastewater treatment plants.
Related Concept Videos
Overview of Nitrogen Metabolism
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this...
Environmental Applications of Microorganisms
Inorganic Nitrogen Assimilation
Metabolism of Chemolithotrophs
The Nitrogen Cycle
Bioremediation


