The Influence of Photocatalytic Reactors Design and Operating Parameters on the Wastewater Organic Pollutants Removal—A Mini-Review

Abstract

The organic pollutants removal by conventional methods (adsorption, coagulation, filtration, microorganism and enzymes) showed important limitation due to the reluctance of these molecules. An alternative to this issue is represented by the photocatalytic technology considered as an advanced oxidation process (AOP). The photoreactors design and concepts vary based on the working regime (static or dynamic), photocatalyst morphology (powders or bulk) and volume. This mini-review aims to provide specific guidelines on the correlations between the photoreactor concept characteristics (working regime, volume and flow rate), irradiation scenarios (light spectra, irradiation period and intensity) and the photocatalytic process parameters (photocatalyst materials and dosage, pollutant type and concentration, pollutant removal efficiency and constant rate). The paper considers two main photoreactor geometries (cylindrical and rectangular) and analyses the influence of parameters optimization on the overall photocatalytic efficiency. Based on the systematic evaluation of the input data reported in the scientific papers, several perspectives regarding the photocatalytic reactors' optimization were included.

Recent advances, influencing factors, and future research prospects using photocatalytic process for produced water treatment

“…Recent studies by Enesca (2021) reported that using the inappropriate photoreactor design may significantly increase energy consumption, improperly distribute photons, or cause the catalyst to deactivate, all of which have an adverse effect on photocatalytic efficiency. (Enesca 2021).…”

“…Recent studies by Enesca (2021) reported that using the inappropriate photoreactor design may significantly increase energy consumption, improperly distribute photons, or cause the catalyst to deactivate, all of which have an adverse effect on photocatalytic efficiency. (Enesca 2021). Thus the main obstacle in the development of highly efficient photocatalytic reactors is the establishment of effective reactor designs for intermediate and large-scale use, as demanded for the purpose of industrial or commercial applications (Abhang et al 2011).…”

Energy Transport of Photocatalytic Carbon Dioxide Reduction in Optical Fiber Honeycomb Reactor Coupled with Trough Concentrated Solar Power

“…(5) The species inside the monolith are homogeneous and incompressible Newtonian fluid. (6) The photocatalyst coating with the same thickness on the reaction surface consists of 2.6wt% NiO/InTaO 4 (imp). The photocatalytic kinetic model was established according the OFMR experiments with NiO/InTaO 4 as catalysts from Liou et al [36] When the photoreaction took place at the room temperature with Mercury lamps as the light source, methanol was measured as the major product.…”

“…Furthermore, the InTaO 4 based photocatalysts show significant potential for photoactivity enhancement by available processes such as the doping process [5]. On the other hand, the photoreactor structure also influences the photocatalytic performance significantly, because it dominates the light transmitting efficiency, molecular diffusion rate, and reaction capacity [6]. Therefore, the design and optimization of photoreactors have attracted a lot of attention [7].…”

A review on the applications of zinc tungstate (ZnWO4) photocatalyst for wastewater treatment

“…Photocatalysis has the advantage of completely mineralize organic pollutants more than other conventional treatment methods such as coagulation, flocculation, co-precipitation, and even precipitation that fail to remove highly toxic pollutants even at low concentrations (Enesca, 2021). There are two main groups of advanced oxidation processes for wastewater treatment: homogenous light-induced technology involving the application of ozonation (UV/O 3 and UV/O 3 /H 2 O 2 ) and photo-Fenton processes (UV/Fe 2þ /H 2 O 2 ).…”