Modelling heterogeneous photocatalytic oxidation using suspended TiO₂ in a photoreactor working in continuous mode: Application to dynamic irradiation conditions simulating typical days in July and February

Abstract

Compared to more conventional techniques, advanced oxidation processes (AOP) hold significant promise in terms of elimination of organic (especially persistent) compounds and microorganisms (disinfection) in wastewater. If the objective is to power these processes using solar energy, we need to be able to manage the intermittency in the solar resource. This is an essential step for design and to ensure efficient operation of the treatment processes. As solar radiation is inherently variable due to day/night cycles, seasonal cycles, and weather meteorological conditions, solar AOP performances are difficult to establish using conventional measures. To address this gap, we carry out experimental campaigns under controlled conditions and develop modelling tools capable of describing dynamic-mode photocatalytic degradation. Here we develop a way to capture the responses of a photoreactor subjected to various stresses, including irradiation conditions, via an LED panel. Using a model that considers the influence of UV flux density and pollutant concentration made, it was possible to represent photoreactor responses under different irradiation conditions and feeds (concentration or flow at the input). The ultimate objective is to study the photocatalytic capacity of the photoreactor under irradiation conditions simulating a real day of sunshine.

Gray Water Recovery System Model by Solar Photocatalysis with TiO₂ Nanoparticles for Crop Irrigation

“…The TiO 2 dose of 2.0 g/L, IUV 13 and an exposure time of 60 minutes, water is obtained with a quality index of 86.35%, to avoid sedimentation, this semiconductor was dissolved in the photoreactor and mobilized with displacements in short times by means of a recirculating water pump programmable from a human machine interface screen and maintaining kinetic efficiency. This, in order to take advantage of the photocatalytic properties of TiO 2 , since it is a semiconductor that, when illuminated by sunlight, generates photocatalysis due to UV radiation, with water acting as a donor and acceptor of electrons so that in the process produces oxidation -causes a reduction of pollutants [Plantard et al, 2021]. Mobility is necessary for the photocatalytic action of TiO 2 to be able to prolong its usefulness, as reported by Jiménez [2015].…”

Continuous degradation of micropollutants in real world treated wastewaters by photooxidation in dynamic conditions

“…The second, photo-process-specific constraint is related to the characteristics of the solar resource, which is by nature discontinuous and thus implies dynamic irradiation conditions during the day (Blanco-Galvez & Malato, 2003;Correia et al, 2011;Malato et al, 2009). In the literature, very few works deal with the operation of photoreactors functioning in continuous mode for the treatment of pollutants (Malato et al, 2016;Plantard et al, 2021). These studies require a mastery of the reactor feeding conditions and the possibility of applying a dynamic irradiation setpoint representative of natural sunshine days.…”

Influence of Gold Nanoparticles on the Photocatalytic Action of Titanium Dioxide in Physical-Chemical Parameters of Greywater

“…There are alternatives for the disinfection of water such as photocatalysis processes, these represent an option in the elimination of organic and inorganic compounds efficiently [Plantard et al, 2021]. They have the characteristics that favor the reduction of pollutants in liquids, such as: reduced time in the inactivation of microorganisms, less toxicological residual effect, mineralization of compounds, decontaminating treatments in low concentration and minimal formation of byproducts, using sunlight as a source of energy [Rueda- Marquez et al, 2020].…”