| abstract |
The present invention relates to a process for workup of nitrite-comprising alkaline process wastewaters from the nitration of aromatic compounds, wherein the alkaline process wastewater is acidified by addition of acids and the offgas which comprises nitrogen oxides and escapes from the acidified process wastewater is worked up, comprising the steps ofn a) acidifying the process wastewater by adding acid to a pH below 5, which forms an organic phase which separates out, an acidic aqueous phase and a gaseous NO x -containing phase, and b) removing the gaseous NO x -containing phase. |