TiO2 and Fe (III) photocatalytic ozonation processes of a mixture of emergent contaminants of water

A mixture of three emergent contaminants: testosterone (TST), bisphenol A (BPA) and acetaminophen (AAP) has been treated with different photocatalytic oxidation systems. Homogeneous catalysts as Fe(III) alone or complexed with oxalate or citrate ions, heterogeneous catalysts as titania, and oxidants such as hydrogen peroxide and/or ozone have been used to constitute the oxidation systems. For the radiation type, black light lamps mainly emitting at 365 nm have been used. The effects of pH (3 and 6.5) have been investigated due to the importance of this variable both in ozone and Fe(III) systems. Removal of initial compounds and mineralization (total organic carbon: TOC) were followed among other parameters. For the initial compounds removal ozonation alone, in many cases, allows the highest elimination rates, regardless of the presence or absence of UVA light and catalyst. For mineralization, however, ozone photocatalytic processes clearly leads to the highest oxidation rates.

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► Ozone/UVA/catalyst lead to total removal of initial organics in less than 15–20 min
► Photo-Fenton, O3/ferrioxalate/UVA and O3/TiO2/UVA lead to the highest TOC removal.
► BPA and AAP are mainly removed through their direct ozone reactions.
► For μg L−1 of pollutants, TST is eliminated through hydroxyl radical oxidation.