The results of secondary effluents ozonation from domestic sewages treatment plants in Havana, Cuba are presented. The ozone effect on some physico-chemical parameters was determined. The ozone gas concentration is the parameter, which exerts the greatest influence on the ozone transferred. The results indicated that ozonation of secondary effluents is a safe disinfection alternative for wastewaters reuse in agriculture or safe disposal, whose effectiveness depends on an adequate application. Therefore, effluents ozonisation can contribute to the environment protection and sustainable development. A preliminary economic comparison is performed between ozonation and chlorination treatments. An ozonation reactor design is proposed.
Keywords: ozone, secondary effluents treatment, disinfection, water reuse