METHOD FOR TREATING WASTE FROM WASTE WATER OF MANUFACTURE OF DYESTUFF

摘要

Process for treating waste from the two-step preparation of perylenetetracarboxylic anhydride, in which in the 1st step the perylimide is obtained which in the 2nd step is hydrolysed to give perylenetetracarboxylic anhydride, characterised in that the waste water containing potassium hydroxide from the 1st step and the waste sulphuric acid from the 2nd step are treated, as a result of which potassium sulphate is obtained.