| abstract |
The invention relates to a method for reclaiming wastewaters which are obtained in the treatment of crude aromatic nitro compounds after the nitration of aromatic compounds, comprising the following steps: (a) single-stage or multistage washing of the crude aromatic nitro compound to obtain at least one organic phase and at least one aqueous phase, and separating off the aqueous phase or aqueous phases, wherein step (a) comprises the addition of a base which is different from ammonia, and then (b) optionally removing organic components from at least some of the aqueous phase or aqueous phases obtained in step (a) by stripping, preferably using steam, then (c) removing, by thermal and/or oxidative breakdown, organic compounds from at least some of the aqueous phase or aqueous phases resulting from step (a) or step (b), then (d) stripping, by distillation, of ammonia from at least some of the aqueous phase or aqueous phases resulting from step (c), and then (e) optionally feeding at least some of the aqueous phase or aqueous phases resulting from step (d) to a biological wastewater treatment. |