Main parameters influencing the design of photocatalytic reactors for wastewater treatment: a mini review

Abstract

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). © 2020 Society of Chemical Industry

Adsorption and Photocatalytic Mineralization of Bromophenol Blue Dye with TiO2 Modified with Clinoptilolite/Activated Carbon

“…The results confirm the occurrence of photocatalysis on the surface of NPs are mostly influenced by their charged ions and the pH of the solutions [18,24]. Thus, the charged ions and change in pH promoted the pollutant's stability, neutralization, agglomeration, and adsorption onto the photocatalyst surface [24]. The high acidic medium-efficiency can be attributed to the presence of negatively charged contaminants in the effluent, which were attracted and adsorbed onto the surface of the positively charged photocatalysts (TiO 2 , Z-TiO 2 and A-TiO 2 ) [21,24].…”

“…In the basic or alkaline medium (pH 8-9), the degradation efficiency of 66%, 64%, and 63% was, respectively recorded for the TiO 2 , Z-TiO 2, and A-TiO 2 . The results confirm the occurrence of photocatalysis on the surface of NPs are mostly influenced by their charged ions and the pH of the solutions [18,24]. Thus, the charged ions and change in pH promoted the pollutant's stability, neutralization, agglomeration, and adsorption onto the photocatalyst surface [24].…”

“…Thus, the charged ions and change in pH promoted the pollutant's stability, neutralization, agglomeration, and adsorption onto the photocatalyst surface [24]. The high acidic medium-efficiency can be attributed to the presence of negatively charged contaminants in the effluent, which were attracted and adsorbed onto the surface of the positively charged photocatalysts (TiO 2 , Z-TiO 2 and A-TiO 2 ) [21,24]. In addition, the low-efficiency exhibited within the basic medium (pH 8-9) may be due to the electrostatic repulsion between the positively charged NPs and the cationic charges in the solution.…”

Degradation of Atenolol in a Rectangular Staircase Photocatalytic Reactor with Immobilized ZnO

“…In recent years, several studies reported on the design of solar photocatalytic reactors aiming at the treatment of wastewater [20][21][22][23][24]. In this concept, a rectangular staircase photocatalytic reactor (RSPR) under solar irradiation ( Fig.…”

Innovative TiO2‐based photocatalysis: recent advances and emerging applications

“…indicated that there are many critical objectives of the research dealing with photodegradation of pollutants, including extending the absorption of bulk TiO 2 into the visible region, switching the artificial light sources (low‐pressure lamp, high‐pressure lamp, and LEDs, etc .) into solar light, recovering the photocatalysts, and deactivation of photocatalysts, etc 2 . Especially, Sacco et al .…”