Procesos de ozonación fotocatalítica para eliminar contaminantes emergentes de aguas residuales urbanas

Abstract

In this work, various emerging contaminants (ECs) degradation has been studied from an urban wastewater through chemical processes sequentially integrated as a pretreatment or tertiary stage to a conventional aerobic biological treatment using activated sludge. Selected compounds are acetaminophen, antipyrine, bisphenol A, caffeine, carbamazepine, diclofenac, hydrochlorothiazide, ketorolac, metoprolol, sulfamethoxazole and testosterone. These ECs were chosen as many studies indicate its presence in wastewater and also in surface waters. The chemical processes have been studied were ozonation, photolysis with natural radiation (sun) and artificial radiation (black light), homogeneous photocatalysis using a solution of Fe (III) catalyst (natural or artificial radiation) and heterogeneous photocatalysis using magnetite as catalyst (natural or artificial radiation). Also, in some cases only by solar radiation, a semiconductor has been used as catalyst, TiO2. In all situations, the combination of ozonation process with radiation in the presence (preferred) and absence (only in some cases) of the catalysts mentioned above (photocatalytic and photolytic ozonation processes) has been studied. In addition, the quality of the final effluent studied has also been considered through the evolution of total organic carbon (TOC) and chemical oxygen demand (COD). Also, the change in the biological oxygen demand (BOD) and effluent toxicity against Daphnia Magna, usually used as ecotoxicological bioindicator, has been studied.