engleski

Water & air purification over TiO2 glass fibers in CPC photoreactors

In this work, application of photocatalytic oxidation of micropollutants (imidacloprid, enrofloxacin, diazepam) often found in surface waters and degradation of air-borne pollutants such as ammonia usually related with the emissions from agriculture were presented. Compound parabolic collector (CPC) reactor was used to study degradation of selected pollutants since nowadays it has been considered as the state of the art system for solar photocatalysis. The CPC reactor has high optical efficiency due to its usage of both direct and diffuse solar radiation and quantum efficiency as they do not receive a concentrated flow of photons. Because it is closed reactor system, it is applicable to study both, water and air pollutant degradation. Also, reactor’s design allows scaling up in order to enhance degradation efficiency. As a photocatalyst, a TiO2 P25 immobilized on a glass fibers was prepared from commercially available materials. The aim was to achieve effective transport of the water and air pollutant on the photocatalysts surface and enable equal distribution of photocatalyst’s irradiation. The modular panel with the full- spectra solar lamps having appropriate UVB and UVA irradiation levels was used as a simulation of sunlight in all experiments. The addition of carbon nanotubes (MWCNT) to photocatalytic films was considered thus resulting in intensification due to enhanced photon absorption in wider wavelength range. Results indicate on a degradation of selected pollutants in CPC reactor in a complete recirculation. Based on the collected experimental data and developed mathematical model including mass transfer considerations and photon absorption, actual degradation constants of the target pollutants were estimated. The model could be effectively applied for different irradiation conditions which makes it extremely versatile and adaptable when predicting the degradation extents throughout the year using sunlight as the energy source at any location.

micropollutans ; ammonia ; titanium dioxide glass fiber ; CPC reactor

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