Continuous-Flow Aqueous System for Heterogeneous Photocatalytic Disinfection of Gram-Negative Escherichia coli

Within the global objective to develop a sustainable oxidative process based on heterogeneous photocatalysis, the possibility of combining solar UV irradiation and a supported semiconductor all while working in an open reactor running in continuous flow is a pertinent option. Here we investigated a heterogeneous photocatalytic disinfection process performed with a 2D-photocatalytic material implemented in an open-flow flat-plate reactor irradiated with a LED panel. Inactivation of Gram-negative Escherichia coli was attempted using different UV light flux densities and feed flow rates. Treatment capacities were calculated under steady-state conditions using a simple mass balance between inlet and outlet. For an irradiated surface of 1.5 × 10-2 m2, values ranged from 10 to 30 × 105 MPN h-1 L-1as a function of working conditions. With just a few adjustments, the model based on coupling mass transfer with phototocatalysis-driven bacterial inactivation developed previously in the case of a closed-batch cylindrical reactor was tested and extended with success.