Process for the treatment of spent aqueous solutions of caustic soda used for purification and washing of petroleum products.

摘要

The process for treatment of spent aqueous solutions of caustic soda used for purification and washing of petroleum-products is based on the synergical use of ozone and calcium hypochlorite. More specifically, the process according to the present invention consists essentially in subjecting the spent aqueous solutions of caustic soda to the following operations: a first oxidization using 0,5-3,5 Kg of O3/Kg of total phenols, at a temperature of between 38 and 42 DEG C; a second oxidation with 5-10% by weight of calcium hypochlorite, referred to the previously ozonized spent caustic soda, at a temperature selected from the range of between 25 and 35 DEG C, with the formation of a pulp with a flaky suspension; and separation of the pulp formed into a liquid phase and a solid phase, each of which can be eliminated in a much easier and safer way, from an ecological point of view, than the initial spent solution of caustic soda.