In this study biomass acclimation in a side stream partial nitrification sequencing batch reactor (SBR) was performed under optimum conditions (T 30ºC, SRT 9± 1 days and hydraulic retention time (HRT) 1.2 day). Excess sludge for solids retention time (SRT) regulation was added to another batch reactor (main stream) which performed under different conditions for partial nitrification evaluation ...

Emission of nitrous oxide (N2O) during biological wastewater treatment is of growing concern since N2O is a major stratospheric ozone-depleting substance and an important greenhouse gas. The emission of N2O from a lab-scale granular sequencing batch reactor (SBR) for partial nitrification (PN) treating synthetic wastewater without organic carbon was therefore determined in this study, because P...

Acclimation of nitrifying bacteria using inorganic carbon source (bicarbonate) and organic carbon source (bicarbonate + glucose) was performed in this study. Sequential batch reactors were inoculated by activated sludge (mixed culture of heterotrophic and nitrifying bacteria), and fed by synthetic wastewater contain high concentration of ammonium (1000 mg·L). Adapted nitrifying bacteria, only u...

nitrification rate of biofilters is influenced by ammonia concentration and levels of ammonia vary in response to feeding time. on the other hand, existence and activity of different groups of bacteria can be expected in the biofilters. hence in this research, nitrification dynamic of biofilters during day hours and also rules of different biofilteration process (nitrification, denitrification ...

Autotrophic ammonia-oxidizing bacteria produce nitrous oxide (N(2)O) as a by-product of nitrification or as an intermediate of nitrifier denitrification. In soil incubations, acetylene (C(2)H(2)) and large partial pressures of oxygen (O(2)) are used to distinguish between these sources. C(2)H(2) inhibits ammonia oxidation and should therefore inhibit N(2)O production by both nitrification and n...

This study investigated the influence of dissolved oxygen concentration and aeration time on nitrification and nitrite accumulation in an attempt to optimize the recently developed biological-partial-nitritation process for the treatment of strong nitrogen wastewaters. Investigation of dissolved oxygen concentration on ammonium and nitrite oxidation was carried out in a batch reactor. The disso...

Bioaugmentation of bioreactors focuses on the removal of numerous organics, with little attention typically paid to the maintenance of high and stable nitrite accumulation in partial nitrification. In this study, a bioaugmented membrane bioreactor (MBR) inoculated with enriched ammonia-oxidizing bacteria (AOB) was developed, and the effects of dissolved oxygen (DO) and temperature on stability ...

In many experiments, a partial nitrification device is initiated with the use of highly active nitrating sludge because large number nitrifying bacteria. Ammonia-oxidizing bacteria (AOB) are more adaptable to low-dissolved oxygen environments than nitrite-oxidizing (NOB). NOB activity was inhibited when dissolved (DO) levels were decreased, causing nitrate-nitrogen concentration gradually decre...