title: Modeling the photocatalytic mineralization in water of commercial formulation of estrogens 17-β estradiol (E2) and nomegestrol acetate in contraceptive pills in a solar powered compound parabolic collector.
abstract: Endocrine disruptors in water are contaminants of emerging concern due to the potential risks they pose to the environment and to the aquatic ecosystems. In this study, a solar photocatalytic treatment process in a pilot-scale compound parabolic collector (CPC) was used to remove commercial estradiol formulations (17-β estradiol and nomegestrol acetate) from water. Photolysis alone degraded up to 50% of estradiol and removed 11% of the total organic carbon (TOC). In contrast, solar photocatalysis degraded up to 57% of estrogens and the TOC removal was 31%, with 0.6 g/L of catalyst load (TiO2 Aeroxide P-25) and 213.6 ppm of TOC as initial concentration of the commercial estradiols formulation. The adsorption of estrogens over the catalyst was insignificant and was modeled by the Langmuir isotherm. The TOC removal via photocatalysis in the photoreactor was modeled considering the reactor fluid-dynamics, the radiation field, the estrogens mass balance, and a modified Langmuir-Hinshelwood rate law, that was expressed in terms of the rate of photon adsorption. The optimum removal of the estrogens and TOC was achieved at a catalyst concentration of 0.4 g/L in 29 mm diameter tubular CPC reactors which approached the optimum catalyst concentration and optical thickness determined from the modeling of the absorption of solar radiation in the CPC, by the six-flux absorption-scattering model (SFM).
authors.affiliation: Program of Chemical Engineering, Universidad de Cartagena Piedra de Bolívar Campus, Av. El Consulado 48-152, A.A. 130015, Cartagena de Indias, Colombia. jcolinam@unicartagena.edu.co.
authors.forename: José
authors.initials: J
authors.lastname: Colina-Márquez
authors.affiliation: School of Chemical Engineering, Universidad del Valle, Campus Meléndez, Calle 13 No. 100-00, A.A. 25360 Cali, Colombia. fiderman.machuca@correounivalle.edu.co.
authors.forename: Fiderman
authors.initials: F
authors.lastname: Machuca-Martínez
authors.affiliation: Environmental Nanocatalysis & Photoreaction Engineering, Department of Chemical Engineering, Loughborough University, Loughborough LE11 3TU, UK. g.lipuma@lboro.ac.uk.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Li Puma
mesh_terms: D002384:Catalysis; D003276:Contraceptives, Oral / Q000737:chemistry*; D004958:Estradiol / Q000737:chemistry*; D008535:Megestrol / Q000031:analogs & derivatives* / Q000737:chemistry; D055668:Photochemical Processes; D012993:Solar Energy; D014867:Water / Q000737:chemistry*
chemical_list: D003276:Contraceptives, Oral; D014867:Water; C047637:nomegestrol; D004958:Estradiol; D008535:Megestrol
keywords: Langmuir–Hinshelwood; UV-photolysis; degradation; emerging contaminants; modeling and simulation; pharmaceuticals; photoreactor design; six-flux model