Aeration
Often the limiting factor in nitrification is that not enough oxygen is present to oxidize ammonia (NH3). Thus one bioremediation strategy to eliminate this pollutant is to aerate the soil or groundwater so that nitrifying bacteria can convert ammonia to nitrate which can then be denitrified to nitrogen gas.
Aeration tanks
The aeration technique has long been in practice for wastewater treatment plants which use aeration tanks to mix air into the wastewater.
Aeration tanks provide aerobic conditions for the nitrifying bacteria Nitrosomonas and Nitrobacter. The air is bubbled into the contaminated water where the oxygen is readily used to oxidize the ammonia to nitrate. Mg(OH)2 is often used to balance the drop in pH that occurs from this process.
Microbial Mats
A new in situ bioremediation technique for aeration is the use of bacterial mats. Permeable polymer mats can deliver oxygen to ammonia contaminated groundwater to stimulate aerobic bacterial nitrification.
A second group of polymer mats can also be placed beyond the first to stimulate denitrification of the resultant nitrate. Instead of oxygen, this second group of mats would deliver a carbon source to ensure anaerobic conditions necessary for denitrification.
Aeration can also be used to bioremediate halogenated organic compounds.
Sources:
Kunert (2004); Paterson (2002); Bioremediation Services Company