DENSAC plant is designed to accept a mixed feed of TNT and Tetryl waste acid. The feed is partially preheated by interchange with either (a) hot denitrated acid from Denitration column or (b) Hot high concentrated Sulphuric Acid out of the concentration boiler, to ensure that the Sulphuric Acid concentration does not drop below 65%. Stripping steam is fed to the base of the column to strip the nitric/nitrous from sulphuric acid & reduce the nitro body content of the acid.