Normally, the food industry produces wastewater containing high organic
matter and nitrogen compounds. Along with organic matter removal from these
streams, also, nitrogen compounds should be removed. Nitrogen can be removed
biologically from wastewater using conventional and novel processes. Although,
conventional nitrification/denitrification is an established system for nitrogen removal
but the costs of treatment by this system are high because of: high oxygen requirement
for nitrification, the addition of external carbon source for denitrification (in the case of
wastewaters with low C/N ratio), slow growth rate of microorganisms responsible for
both processes, and needing two successive reactor or difficult control of one-reactor
system. These disadvantages led to conduction of substantial studies to find better
alternatives. Therefore, different novel processes were studied and used for nitrogen
removal. Many autotrophic processes including SHARON, ANAMMOX, SHARONANAMMOX,
CANON, and OLAND were discovered to be more economical than
conventional nitrification/denitrification system. Also, more studies on combination of
novel processes with a part of conventional nitrification/denitrification process led to
the development of other novel processes such as heterotrophic nitrification-aerobic
denitrification, NOx, and DEAMOX processes. Details of both conventional and novel
processes were discussed in this chapter. Finally, the possibility of using these
processes to remove nitrogen from food industry wastewater is discussed. Because of
co-existence of both carbon and nitrogen compounds in food industry wastewater, the
use of novel autotrophic processes for mainstream wastewater treatment is impossible.
So, carbonaceous contaminants should be removed using anaerobic digestion or high
load conventional activated sludge, and then effluent of these processes with high
nitrogen contents (low C/N ratio) can be treated using novel autotrophic processes. It should be noted that there are two alternatives including heterotrophic nitrificationaerobic
denitrification process and organic-laden DEAMOX process that can be used
for mainstream food industry wastewater treatment but the exact characteristics of
these processes are unclear and should be accurately studied in laboratory, pilot and
full-scale before use.
Keywords: Aerobic Deammonification, ANAMMOX Process, CANON Process,
Conventional Nitrification/denitrification, DEAMOX Process, Food Industry,
Heterotrophic Nitrification-aerobic Denitrification, Nitrogen Removal, NOX
Process, OLAND Process, SHARON Process.