Method and apparatus for treatment of effluents from production plants of epoxy compounds

A process of treatment in a plant comprising a chlor-alkali electrolysis unit, upstream of the chlor-alkali electrolysis unit comprising a pre-oxidation unit and an oxidation unit, the process consisting of the following sequential steps:

• a) feeding fresh brine to the chlor-alkali electrolysis unit to obtain products;
• b) oxidizing an organic raw material with the products obtained from step a), thereby obtaining an epoxy compound and a depleted brine;
• c) extracting a waste stream consisting of the depleted brine from step b) and vapor stripping the waste stream to obtain a vapor-stripped stream;
• d) pre-oxidating the vapor-stripped stream from step c) in the pre-oxidation unit with hypochlorite at pH 3.5 to 5 and at a temperature of 50 to 60° C.;
• e) followed by oxidating the material from step d) in the oxidation unit by further adding hypochlorite at pH 3 to 4 and at a temperature of 80 to 95° C. until obtaining a fresh brine;
• and
• f) feeding the fresh brine obtained from step e) to the chlor-alkali unit in step a).