7. Conclusions and outlook

This dossier will have shown how and how much NO _x is damaging our precious environment, and the various sources of anthropogenic NO _x emissions will have been clarified.

As far as stationary industrial sources are concerned (combustion units, nitric acid production units, nitric attack reactors), we have seen that there is a wide range of processes for reducing nitrogen oxide emissions.

Whatever the source, the philosophy for reducing emissions is the same: first, try to take action at the process level; then, if necessary (which is more and more often the case as legislation intensifies), apply other reduction techniques, downstream of the source, on the gaseous effluents from the sources.

The choice of a technique is a...