Ammonia removal is a common requirement of industrial and sewage treatment processes.
Aerofloat has extensive experience in designing treatment plants for the management and removal of Nitrogen in the form of ammonia, nitrites, and nitrates from wastewater. A typical treatment plant will consist of an anoxic reactor (AR) and a sequence batch reactor (SBR). Depending on the wastewater, sometimes a nitrifying reactor (NR) is used between these 2 reactors.
Nitrogen can be removed biologically through the nitrification and denitrification processes. Ammonia exerts an oxygen demand on the microorganisms, and if given enough oxygen, the microorganisms will oxidise the ammonia to nitrites and nitrates. Controlled aeration of the SBR optimises the nitrification process by ensuring sufficient dissolved oxygen is present:
Nitrification: NH3 + O2 à NO3 + H2O (not stoichiometrically balanced)
Nitrates and nitrites are then reduced to nitrogen gas where no dissolved oxygen is present, forcing the microorganisms to use the oxygen in the NOx molecule and liberate nitrogen gas to the atmosphere. By returning the mixed liquor to the upfront anoxic reactor (AR) at high flowrates, the denitrification process will occur (in the AR) by the denitrifying organisms being mixed and utilising the available carbon as the electron donor in the incoming wastewater. Depending on the wastewater sometimes supplementary carbon may need to be added.
Denitrification: NO3 à N2 + H2O (not stoichiometrically balanced)
Aerofloat engineers thrive on having a detailed understanding the physical, chemical and biological processes in managing contaminants degradation in wastewaters.
Aerofloat’s design allowed for increases in flow rates and ammonia concentration during peak flows. The plant achieved results beyond the initial scope, managing peak loads of 2000mg/L of ammonia and still achieved strict Sydney water ammonia and nitrogen discharge limits.
Aerofloat worked with a Queensland Council to upgrade its sewage treatment plant (STP) to ensure compliant effluent and a low environmental footprint.
An Australian university recently worked with Aerofloat to create a wastewater treatment design that was sensitive to the historical significance of its site.
