Ozone has been used in treatment of municipal wastewater effluents primary for disinfection. However, its powerful capacities to react with organic matter in wastewater led to another application of ozone in water treatment. Heterotrophic cultivation of green algae Chlorella zofingiensis in ozonated waste water was used to remove nutrients and also to collect Astaxanthin. Results of this study shows ozonation did not remove but produce transformation of organic matters
increase capacity of dissolved organic carbon and dissolved nitrogen removal of Chlorella zofingiensis as well. The ozonation - heterotrophic cultivation of Chlorella zofingiensis process could be used in domestic wastewater treatment. However, as the dual-goal of algae cultivation, astaxanthin production in this process was not effective