This study revealed the presence of nitrifying bacteria in influent municipal wastewaters reaching full-scale biological wastewater treatment plants. Respirometric assays showed that the influent nitrifiers were active following a 5- to 8-hour period of metabolic induction. Diversity analyses by pyrosequencing of functional gene PCR (polymerase chain reaction) amplicon suggested that the nitrifiers in the influent stream likely seeded activated sludge bioreactors since the most abundant operational taxonomic units in the influent and mixed liquor were the same. Based on the estimated seeding intensity of 0.3 g of nitrifiers per day per gram of nitrifiers already present, the absolute minimum solids retention time (SRT) was reduced by approximately 56% at 5 °C as compared to non-seeding conditions. This can have important repercussions on the design and sizing of bioreactors operating in cold climates and calls for a need to fine-tune process modelling by considering the contribution of autotrophic nitrifying biomass from municipal influent streams.
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Research Article|
September 26 2014
Should activated sludge models consider influent seeding of nitrifiers? Field characterization of nitrifying bacteria
Shameem Jauffur
;
Shameem Jauffur
1
Department of Civil Engineering and Applied Mechanics, McGill University, 817 Sherbrooke St. West, Montreal, Quebec. Canada H3A 0C3
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Siavash Isazadeh
;
Siavash Isazadeh
1
Department of Civil Engineering and Applied Mechanics, McGill University, 817 Sherbrooke St. West, Montreal, Quebec. Canada H3A 0C3
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Dominic Frigon
1
Department of Civil Engineering and Applied Mechanics, McGill University, 817 Sherbrooke St. West, Montreal, Quebec. Canada H3A 0C3
E-mail: dominic.frigon@mcgill.ca
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Water Sci Technol (2014) 70 (9): 1526-1532.
Article history
Received:
June 21 2014
Accepted:
September 12 2014
Citation
Shameem Jauffur, Siavash Isazadeh, Dominic Frigon; Should activated sludge models consider influent seeding of nitrifiers? Field characterization of nitrifying bacteria. Water Sci Technol 1 November 2014; 70 (9): 1526–1532. doi: https://doi.org/10.2166/wst.2014.407
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Shameem Jauffur, Siavash Isazadeh, Dominic Frigon; Should activated sludge models consider influent seeding of nitrifiers? Field characterization of nitrifying bacteria. Water Sci Technol 1 November 2014; 70 (9): 1526–1532. doi: https://doi.org/10.2166/wst.2014.407
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