Solar photoelectro-Fenton-like process with anodically-generated HClO in a flow reactor: Norfloxacin as a pollutant with a particular structure

The degradation and mineralization of the drug norfloxacin (NFX) has been assessed in a model solution, containing 15 mM NaCl +45 Na2SO4 at pH 3.0, using flow plant with an FM01-LC filter-press reactor equipped Ti|Ir-Sn-Ru oxides anode to electrogenerate HClO from Cl− oxidation stainless-steel cathode. Unexpectedly, anodic active chlorine (AO-HClO) outperformed electro-Fenton (EF-HClO), photoelectro-Fenton (PEF-HClO) solar (SPEF-HClO) due to: (i) formation refractory complexes between iron ions carboxyl group NFX, (ii) conversion into less effective •OH upon its Fenton-like reaction added Fe2+ catalyst. SPEF-HClO was superior among Fenton-based treatments because concentration largely increased by photolysis Fe(III) species. At initial NFX range 0.103–0.146 mM, optimum conditions for were 0.40 mA cm−2. A BDD allowed higher production •OH, accelerating mineralization, similar energy requirements as compared trials anode. process urban wastewater powerful parallel natural organic matter. HClO, Fetotal quantified both water matrices. sequence proposed 10 primary by-products identified LC-MS/MS, revealed occurrence hydroxylation, chlorination defluorination steps. Additionally, 5 stable detected GC–MS.