Photochemical treatment of simulated dyehouse effluents by novel TiO2 photocatalysts: experience with the thin film fixed bed (TFFB) and double skin sheet (DSS) reactor

This study has been undertaken to provide a rather practical assessment of the heterogeneous photocatalytic treatment of two simulated reactive dye-ba th effluents via three commercial TiO2 types (Degussa P25, Millennium PC 50 0 and Sachtleben Mikroanatas), which were employed in fixed film and suspen ded photochemical reactor configurations. The obtained results have clearly revealed that the inherent advantage of eliminating a proceeding photocata lyst separation step did not justify the significantly lower treatment perf ormance of the thin film fixed bed (TFFB) reactor, which is directly reflec ted in the values obtained for percent photonic efficiencies (% zeta), firs t-order decolourisation rate constants (k(d)) and the collector area requir ements per unit of mineralisation rate (CA/M), as compared to the more rece ntly developed suspended double skin sheet (DSS) photoreactor. Generally sp eaking, Degussa P25 was found to be most efficient among the investigated T iO2 photocatalyst types.