SHUNT BIOFILTRATION: A CONCEPT AND DESIGN FOR INCREASING
CAPACITY (view also as Keywords: biofilter, shunt, airlift,
pumps, recirculating, systems, aquaculture Aquaculture 2004;
Honolulu, HI; March 4, 2004. Book of Abstracts, p. 652 William
A. Wurts, Ph.D., Aquaculture Specialist It is commonly
understood that nitrifying bacteria break down nitrogenous
wastes, ammonia and nitrite, in recirculating systems. These
bacteria coat the surfaces of the biofiltration media. As the
effluent water exits the culture tank and flows into the
biofilter chamber, ammonia and nitrite are brought into contact
with the biofiltration media. The bacteria absorb these wastes,
and oxygen is combined with the nitrogen, presumably through
enzyme-protein activity. Ammonia and nitrite are then converted
to nitrate, which is not toxic to most aquatic animals. Because
the bacteria must absorb these compounds from the effluent
water, nitrification is dependent on waste concentration and
contact time (exposure) of water with the biofiltrat