Denitrification of nitrite in a two-phase fluidized bed bioreactor

Abstract

Denitrification of nitrite-nitrogen carried out experimentally in an anoxic two-phase fluidized bed bioreactor is described, and the characteristics of the biological treatment were also theoretically studied. Methanol was used as the carbon source, and nitrite-degrading bacteria immobilized on CB particles were employed. A method for evaluating the characteristics of the biological treatment is proposed. Within the range of the experiment, the results show that denitrification of nitrite-nitrogen could be approximated by Monod-type reaction kinetics, characteristic values for the biological treatment of Ku = 5.0 kg-N·kg−1-VS·d−1 and Ku/Km = 23.8 m3·kg−1-VS·d−1 being obtained. There was good correlation between the experimental results and the calculated curves. A maximum volumetric denitrification rate for nitrite of 18.7 kg-N·m−3·d−1 was achieved, this high value demonstrating the high efficiency of an anoxic two-phase fluidized bed bioreactor to denitrify nitrite-nitrogen.

Nitritation and denitritation of ammonium-rich wastewater using fluidized-bed biofilm reactors

“…Although the removal efficiency was higher than 90% at the highest loading rate, NO 2 -N and NO 3 -N concentrations in the effluent were shown to be above 15 mg/l when the NO x -N loading was higher than 0.25 kg N/m 3 day. [45]. The denitritation rate in this study was around 0.24 kg NO 2 -N/m 3 day at 21 • C. The denitritation rate could be increased by operating the reactor at a high temperature or modifying the reactor operation.…”

Mathematical modeling and simulation of a two‐phase fluidized‐bed bioreactor with an external aerator

“…Fluidized‐bed bioreactors can be classified by the number of phases into two‐phase liquid‐solid bioreactors and three‐phase gas‐liquid‐solid bioreactors . The operation of aerobic microbiological processes in two‐phase bioreactors is possible by the use of an external aerator.…”

“…10 Occurrence of this phenomenon leads to significant decrease in the bioreactor performance. 6 Fluidized-bed bioreactors can be classified by the number of phases into two-phase liquid-solid bioreactors [11][12][13] and three-phase gas-liquid-solid bioreactors. [14][15][16][17][18] The operation of aerobic microbiological processes in two-phase bioreactors is possible by the use of an external aerator.…”

A novel two-stage MBR denitrification process for the treatment of high strength pet food wastewater

“…Though conventional studies of denitrification have been driven primarily by the requirement to meet stringent nitrogen discharge criteria, immense work has been done on impact of various carbon sources [7][8][9], role of diverse microbial cultures kinetics [10][11][12] and optimization [5]. Research on enhancement and optimization of process designs using pre-denitrification has been limited.…”