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Abstract: The purpose of this study was to develop a municipal wastewater treatment method based on a solar advanced oxidation process (AOP) permitting reuse of the treated wastewater. The photoactive layer of TiO2 was deposited on glass spheres using the sol–gel dip-coating technique. The film was characterized by X-ray diffraction and scanning electron microscopy (SEM). Degradation of 15 emerging contaminants (ECs), each with an initial concentration of 100μgL−1 was determined by ultra-performance liquid chromatography (UPLC–UV) and mineralization was monitored by measuring the dissolved organic carbon (DOC). The experiments were performed in a pilot compound parabolic collector (CPC) solar plant at the Plataforma Solar of Almeria. Five cycles of photocatalysis were studied for photocatalyst durability and activity. It was demonstrated that after five cycles, although photoactivity of the catalyst slowly decreases, it continues degrading contaminants. [Copyright &y& Elsevier]

Highlights: [•] Immobilized photocatalyst based on TiO2 on glass spheres was successfully applied for ECs removal. [•] Regeneration with H2O2/UV or calcination are the most efficient methods to recover photoactivity. [•] F-, S- and Cl-containing compounds are preferentially adsorbed and easily removed from titania acid sites. [•] Compounds containing amine and amide groups are resistant to the photodegradation. [ABSTRACT FROM AUTHOR]

Abstract: This article reports on degradation using TiO2 immobilized on glass spheres of 15 emerging contaminants (ECs) at low concentrations in simulated and real Municipal Wastewater Treatment Plant (MWTP) effluents. A sol containing titanium isopropoxide, commercial P25 and polyethylene glycol (PEG) was prepared, and a layer of the photoactive precursor was immobilized on glass spheres by dip-coating. The raw materials and the xerogels were characterized by N2 adsorption/desorption, XRD and TGA-DTA. The xerogel showed the TiO2 anatase, rutile and brookite crystal phases characteristic of the reference materials. The diffraction pattern showed no modification of the crystal size from incorporation of the PEG. Two different TiO2 anatase crystal sizes were identified, which was attributed to the different TiO2 precursors used in the synthesis route. Degradation of the emerging contaminants (acetaminophen, antipyrine, atrazine, carbamazepine, diclofenac, flumequine, hydroxybiphenyl, ibuprofen, isoproturon, ketorolac, ofloxacin, progesterone, sulfamethoxazole and triclosan), at an initial concentration of 100μgL−1 each was determined by ultra-performance liquid chromatography (UPLC-UV) and mineralization was monitored by measuring the dissolved organic carbon (DOC). The experiments were performed in a pilot compound parabolic collector (CPC) solar plant at the Plataforma Solar of Almeria (Spain). 85% of the compounds were degraded within 120min of illumination time depending on the water. The results show the potential application of this technology as a good alternative to suspension systems for the treatment of polluted water. [Copyright &y& Elsevier]