| abstract |
The invention relates to a method for treating alkaline nitriding process waste water from aromatic compounds to monodi-and trinitro-aromatic compounds having a value of pH 7.5 to 13, comprising the steps of a) acidulating wastewater from alkaline process by the addition of concentrated sulfuric acid, which results from the treatment of the sulfuric acid-containing aqueous phase occurring during nitration, to a ph value below 5, with a mixture a obtained from a separation of organic phase and aqueous phase b) contact the mixture a with fresh sludge c) separate the sludge. |