Ammonia Removal from Wastewaters: A Review of the State of the Art.

Processes applicable to the removal of ammonia present in munitions plant waste streams were reviewed and evaluated. The high levels of ammonia, nitrates, and the presence of various explosive wastes contained in the wastewaters present unique problems to ammonia abatement processes. Abatement regulations require removal of both the ammonia and nitrates from these munition plant waste streams. Several processes are effective in the removal of ammonia from wastewaters, but they do not reduce the nitrate concentration. Other processes must be employed to accomplish the nitrate removal, thus imposing additional costs. Ammonia removal processes such as air stripping, ion exchange, and breakpoint chlorination are examples of methods that are only effective in removing ammonia. Biological nitrification-denitrification is an effective two-step abatement process for reducing both ammonia and nitrate concentrations in the wastewater. It is a clean, efficient, and cost-effective process in which ammonia is biologically oxidized to nitrite, then to nitrate which, in turn, is reduced to nitrogen gas by the biological dentrification process.