Processing waste acid obtained from nitroaromatics production, preferably dinitrotoluene- or trinitrotoluene production, comprises: adding a pre-heated waste acid comprising sulfuric acid, water, nitric acid, nitrosylsulfuric acid and nitro-organics, into a stripping column in a counter-flow to the steam obtained from the bottom of the stripping column by heating a pre-concentrated sulfuric acid; separating nitric acid, optionally nitro-organics and the pre-concentrated sulfuric acid into at least one vapor phase; and processing the obtained nitric acid and the nitro-organics. Processing waste acid obtained from nitroaromatics production, preferably dinitrotoluene- or trinitrotoluene production, under recovery of concentrated and purified sulfuric acid and nitric acid, comprises: (i) adding a pre-heated waste acid comprising sulfuric acid and water (up to 80 wt.%), nitric acid, nitrosylsulfuric acid and nitro-organics, preferably dinitrotoluene and mononitrotoluene, into a stripping column in a counter-flow t
