Bio Tower
Aerobic Effluent Treatment
Introduction
During
the treatment of domestic sewage or industrial wastes, biological processes
are employed to reduce the biochemical oxygen demand (BOD) and in some
cases the ammoniacal nitrogen concentration of the effluent.
The BOD is an empirical measurement which has been universally adopted
to quantify the amount of oxygen (expressed in terms of mg/l or ppm)
which would be consumed if the carbonaceous organic matter present in
the waste water were oxidised by a population of micro organisms.
The process of BOD and ammoniacal nitrogen removal is termed ‘biological
oxidation’ and is achieved by providing an environment in which both
oxygen and organic matter are brought into intimate contact with a population
of micro organisms. Biological oxidation is carried out in either high
energy ‘activated sludge’ systems in which the micro organisms are dispersed
in a suspended form throughout the waste water or in low energy fixed
film bio-reactors where micro organisms grow as a film over an inert
fixed surface.
|
