The research in the heterogeneous photocatalysis to remove different types of pollutants in liquid phase has notably increased in the last years. The main objectives of the research dealing with photocatalysis were: (i) to shift the photoactivity of catalysts in the visible light range or to increase the degradation rate; (ii) the use of the artificial light sources (low pressure lamp, high pressure lamp, LEDs, and optical fibers) and solar light; (iii) photocatalysts recovering and deactivation; (iv) photoreactor configuration; (v) photodegradation of contaminants of emerging concern; and (vi) verification of induced effects from the photocatalytic treatment, such as the induction of bacterial resistance. Here, one of the main problems in the practical application of photocatalysis, which is the photoreactors scale-up, is addressed with the use of mathematical modeling. In this perspective, this mini review reports a literature exam of the main parameters that are important to take into account for the design and the development of photoreactors for wastewater treatment, and through the use of computational fluid dynamics models (CFD). (c) 2020 Society of Chemical Industry