Modeling, simulation, and theory of the mass transfer mechanism of photocatalytic membrane reactor

Advanced oxidation processes with photocatalysis can effectively destroy the organic pollutants in wastewater such as phenols, pesticides, pharmaceuticals, and dyes that have serious impacts on human health and aquatic life. Hence, many attempts have been made to construct photocatalytic reactors and test their performance, especially using titanium dioxide (TiO2), a semiconductor, as the photocatalyst. Among others, the photocatalytic membrane reactor (PMR) demonstrated its high efficiency due to its synergistic combination of the photocatalytic reaction and membrane separation. Thus, PMRs of many different configurations have been constructed and their performances were tested experimentally in the laboratory. Nevertheless, a detailed reactor simulation rarely can be found, despite PMR’s special feature of light intensity attenuation where the light keeps traveling in the reactor. To fill this knowledge gap, an attempt is made in this work to simulate the performance of phenol removal from aqueous solution using different types of photocatalytic reactors and using only separation by a nanofiltration membrane. The process simulation is made for the following three cases: 1. Batch slurry-type photochemical reactor with TiO2 nanoparticles and ultraviolet (UV) irradiation; 2. Semibatch PMR system with TiO2 nanoparticles and with UV irradiation; 3. Semibatch system without TiO2 nanoparticles and without UV irradiation; 4. The comparison of the above three cases is highlighted in the end.