EFFECT OF DISSOLVED OXYGEN CONCENTRATION ON NITRIFICATION AND DENITRIFICATION

The effectof the dissolved oxygen concentration onthe nitrification and
denitrification has beeninvestigated worldwide by numbers of researcher. It hasbeen
proposed that several others factors also has affected the rate of the nitrification and
denitrification process such as the pH, temperature, inhibitory andtoxicmaterials.
However, for this research, only the dissolved oxygen factorwill be studied.
Themainobjective of thisresearch is to study the effectof dissolved oxygen
concentrations on the rate ofnitrification and denitrification process. In addition to that,
this research also will include the studyof someof the equations which weredeveloped
by other researchers in order to determine theeffect ofDO concentrations ontherate of
the nitrification and denitrification process.
For this research, theequation formass transport which is solved byQUAL2E is
going to beputto test by using theFEMLAB software. This equation includes theeffects
of advection, dispersion, dilution, constituent reactions and interactions, and sources and
sinks. However, only the sources and sinks factor is beingmodified.
Fornitrification, it is proven thatastheDO concentration increases, the growth
rate ofthe nitrifiers will also increase. Hence, the nitrification rate will also increase. For
this nitrification process, theDouble-Monod equation is found to best fittheresearch
objective.
For denitrification, it is also proven that as theDOconcentration increases, the
growth rate of denitrifiers will decreases. Hence, the nitrification rate will also decrease.
For this process, the Activated Sludge Model (Two-parameter Model) equation is found
to best fit the research objective in determining the effectof dissolved oxygen
concentration in denitrification.
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