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Kinetics of biofilm nitrification
Author(s) -
Tanaka H.,
Dunn I. J.
Publication year - 1982
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260240311
Subject(s) - nitrification , chemistry , oxygen , stoichiometry , effluent , nitrobacter , diffusion , biofilm , limiting oxygen concentration , kinetics , fluidized bed , analytical chemistry (journal) , thermodynamics , environmental chemistry , nitrogen , environmental engineering , organic chemistry , engineering , physics , bacteria , genetics , biology , quantum mechanics
The reaction rates ( r NH 4 +and r NO 2 −) in the two‐step nitrification reaction were measured in a fluidized‐sand‐bed biofilm reactor under a range of steady‐state conditions with respect to bulk NH 4 + , NO 2 − , and O 2 concentrations. It was shown from theory and experiment that under low NH 4 +concentration conditions, if the O 2 /NH 4 +concentration ratio in the bulk liquid is less than the stoichiometric coefficient (3.4 mg/mg), then oxygen will be rate limiting. In all experiments r NO 2 −decreased more than r NH 4 +under low oxygen conditions. This resulted in high NO 2 −effluent concentrations under low residence time conditions. The influence of the oxygen penetration effects on the relative values of r NH 4 +and r NO 2 −was experimentally shown to be caused either by the Nitrobacter location in the inner biofilm regions or by a K m effect for oxygen. Theoretical support of these findings was provided by a differential diffusion‐reaction model which was used to simulate the experimental results.