METHOD FOR TREATING NOX-CONTAINING EXHAUST GAS FROM PROCESS WASTEWATER FROM NITRATION FACILITIES

摘要

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 of 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 NOx-containing phase, and b) removing the gaseous NOx-containing phase.