Page 56 - March 2020 - WT Site

e) High effluent quality in terms of BOD and suspended to attain good efficiency results of disposal with low energy
solids removal; in combination with a primary and tertiary consumption. This process is used for the removal of organic
treatment also in terms of pathogens substances, nitrification and denitrification.

f) Requires regular operator attention The Moving Bed Biofilm Reactor system consists of an activated
sludge aeration system where the sludge is collected on recycled
g) Some residential systems require forced aeration units which plastic carriers. These carriers have an internal large surface for
will increase maintenance and operational costs
optimal contact water, air and bacteria. The bacteria grow on
h) Efficient nitrification (ammonium oxidation) the internal surface of the carriers. The bacteria break down the
organic matter from the wastewater.
i) Resistant to shock loads
The aeration system keeps the carriers with activated sludge in
j) Incidence of clogging is relatively high motion. Only when there is extra amount of bacteria growth, the

excess sludge will come separate from the carriers and will flow
4. Moving Bed Biofilm Reactor
with the treated water towards the final separator. The system can
Moving bed Biofilm reactors are more advanced technology to consist of a one stage or more stage system, depending on the
the conventional trickling filter. In this process the aeration tanks specific demands. The specific bacteria remain in their own duty
are filled with small moving porous biofilm carriers held in the tank because of the fact that the carriers remain in only 1 tank
basin by media retention sieves. These plastic biofilm carriers protected by screens.
are typically half- to one-inch diameter cylinders or cubes and
are designed to be suspended with their immobilized biofilm Review:
throughout the bioreactor by aeration or mechanical mixing. a) Higher effective sludge retention time (SRT) which is
Because of the suspended moving bio-film carriers, Moving Bed favorable for nitrification
Biofilm Reactor allow high BOD wastewaters to be treated in a
smaller area with no plugging. b) Responds to load fluctuations without operator intervention
c) Lower sludge production
These solutions significantly increase the capacity and efficiency
of existing wastewater treatment plants, while minimizing the d) Less area required
size of new plant deployments. This method makes it possible e) Resilient to toxic shock

58 Water Today - The Magazine March 2020