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International audience; The analysis of radiative transfer in photoreactors is often crucial for operating efficient photoreactions. This article aims to present a complete experimental and theoretical coupled approach allowing radiative transfer analysis of photoreactors containing particulate media. TiO 2 powder, widely used in photocatalysis, was selected as a case study material for this work. First, Mie theory was used and adapted to assess the effective properties of heterogenous powders. A home-made experimental bench allowing normal-hemispheric transmittance measurement was settled. Theoretical and experimental evaluations of the radiative properties were compared and appear to match each other. The second part of the work consisted in both transmittance and local radiant energy modeling through Monte Carlo and Two Flux models using the previously defined radiative properties as entry parameters. The comparison of experimental and modeled transmittance highlighted the consistence of these models which were then used to describe the radiant energy evolution inside a parallelplane photoreactor.

International audience; Activated-Carbon/Titania composites (AC/TiO2) is a relevant option to gather the dual adsorption/photodegradation property within a single material. This work aimed to investigate the composition influence on the adsorption and photodegradation properties of AC/TiO2 composites against caffeine. TiO2 grafted AC powders covering the whole composition scale were synthesized by a one-step mechanical milling process. This original simple elaboration route led to the obtention of powders which particles size and composition were homogeneous and well controlled. When the adsorbent mass ratio varied in the range 0.01−0.75, the adsorption properties, i.e. apparent kinetic and maximum adsorption capacity of the composites increased respectively by 1 and 2-log. At the opposite, the photo-oxidation rate decreased significantly when the adsorbent ratio increased. The simple elaboration route explored produces flexible AC/TiO2 composites with adjustable properties that can easily be managed to meet the requirements of different target applications.