Tandem waste stream treatment for the removal of nitroaromatics and nitrophenolics

摘要

A process for removing nitroaromatic and nitrophenolic compounds from an alkaline wastewater stream generated in a process for the nitration of aromatic compounds by the mixed acid technique, which comprises(a) adjusting the pH of the aqueous alkaline waste stream containing nitroaromatic and nitrophenolic compounds to a range from about 2 to 4.5,(b) contacting the acidic aqueous stream with sufficient hydrogen peroxide and ferrous ion under conditions to effect oxidation of the nitrophenolic compounds,(c) adjusting the acidic, oxidized aqueous waste stream having a reduced nitrophenolic content to about pH ≧ 4, and(d) contacting the aqueous waste stream with a carbon adsorbent.