Intensification of a flat-plate photocatalytic reactor performances by innovative visible light modulation techniques: A proof of concept

Capua, Giulia Di; Femia, N.; Migliaro, Mario; Sacco, Olga; Sannino, Diana; Stoyka, Kateryna; Vaiano, Vincenzo

doi:10.1016/j.cep.2017.05.004

Cited by 12 publications

(6 citation statements)

References 18 publications

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“…In particular, the best results in terms of urea degradation (about 92% in less than 1 h of irradiation) have been achieved with a pseudosinusoidal The effect of the LED light modulation technique on the photocatalytic activity is clearly evident. At variable LED dimming duty-cycle modulations, either S-VD or PS-VD promoted the photocatalytic performances with respect to the irradiation realized at fixed dimming duty cycles, as already observed for methylene blue discoloration [15]. In particular, the best results in terms of urea degradation (about 92% in less than 1 h of irradiation) have been achieved with a pseudosinusoidal modulation.…”

Section: Influence Of Visible Led Modulationsupporting

confidence: 68%

“…Recently, in our previous works [15,16], it was observed that light irradiation with the modulation of a visible LED dimming duty-cycle strongly improved the photocatalytic performances of an active visible light photocatalyst towards methylene blue degradation. To our best knowledge, the use of LED dimming duty-cycle modulation techniques in a photocatalytic system for urea degradation using a visible light photocatalyst immobilized on macroscopic supports has never been reported.…”

Section: Introductionmentioning

confidence: 99%

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Use of Visible Light Modulation Techniques in Urea Photocatalytic Degradation

Vaiano

Sacco

Capua

et al. 2019

Water

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The aim of this work was to analyze the effect of visible LED dimming duty-cycle modulation techniques in a photocatalytic system for urea degradation using a visible light photocatalyst immobilized on macroscopic supports. For this reason, the effect of different LED dimming techniques was investigated and compared in terms of urea degradation together with ammonia and nitrate production during the irradiation time. The experimental results evidenced that using a visible LED dimming modulation with variable-peak variable-duty pulse-width modulation (PWM) allows to improve the photocatalytic degradation process, with respect to classical LED dimming with fixed-peak fixed-duty PWM, and influences the product's distribution of ammonia and nitrate in water. Therefore, the proof of concept herein proposed could be considered as preliminary potential results to be used in water recycling applications with a particular emphasis in recovery of urea photodegradation byproducts, such as ammonia, from wastewater that could be used as potential resources and an energy resource.

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Section: Influence Of Visible Led Modulationsupporting

confidence: 68%

Section: Introductionmentioning

confidence: 99%

Use of Visible Light Modulation Techniques in Urea Photocatalytic Degradation

Vaiano

Sacco

Capua

et al. 2019

Water

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“…To evaluate the influence of light modulation on the efficiency of the water treatment process, a batch system composed of a recirculating photocatalytic reactor (RPR) (30 × 20x5 cm) irradiated by a matrix of 240 white-light LEDs was used. The flat geometry of the photoreactor guarantees the efficient excitation of structured photocatalyst by minimizing the photons loss inside the core of the reactor and, therefore, optimizing the photonic flow inside the photocatalytic bed [15].…”

Section: Experimental Set-up For Photocatalytic Testsmentioning

confidence: 99%

“…In our previous works [15][16][17][18], it was observed that visible irradiation with the modulation of visible LEDs dimming duty cycle remarkably enhanced the photocatalytic performances towards methylene blue, urea and terephthalic acid degradation. To our best knowledge, the use of LED dimming duty-cycle modulation techniques in a photocatalytic system to photodegrade the azo dye Acid Orange 7 (AO7), using a visible light active structured photocatalysts in a flat plate photoreactor, has never been reported.…”

Section: Introductionmentioning

confidence: 99%

Visible light-driven degradation of Acid Orange 7 by light modulation techniques

Sannino

Morante

Sacco

et al. 2022

Photochem Photobiol Sci

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The impact of light modulation on the decolorization of Acid Orange 7 (AO7) in aqueous solution was examined in this paper. A fixed bed batch photocatalytic reactor with a flat plate geometry, irradiated by 240 white-light LEDs, was used. A successful transfer of visible active photocatalyst (N-TiO2) in powder form on a polystyrene (PS) transparent plate was realized. The structured photocatalyst was characterized through SEM–EDX, Raman and UV-DRS analyses, evidencing the formation of a coating of N-TiO2 in the anatase phase, with a band-gap energy of 2.5 eV, and almost uniform distribution on the PS surface. Different LED dimming techniques, with fixed and variable duty-cycle values, were tested, and four types of light modulation were compared: fixed duty cycle (constant irradiation), sinusoidal variable duty cycle (sinusoidal variable irradiation), triangular variable duty cycle (triangular variable irradiation), and square wave variable duty cycle (square wave variable irradiation). The resulting responsiveness/efficiency of the LED versus the current intensity was evaluated, and the stability of the photocatalyst activity and the influence of optimized irradiation waveforms were examined in the decolorization of 400 mL of 10 ppm AO7 solution. The sinusoidal modulation, with current between 50 and 100 mA and 10 s as the period, shows the highest value of the apparent pseudo-first-order kinetic constant, resulting equal to 0.0044 min−1, at parity of total transmitted photons. An energy saving with the application of sinusoidal irradiation is highlighted with respect to the literature. Graphical Abstract

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“…The presence of structured catalyst will increase the removal rate due to the higher surface exposure to light irradiation. The second reactor has a volume of 0.3 L [90] and work in a higher flow rate (0.15 L/min). The photocatalytic efficiency after 180 min of irradiation with a 36 W Vis light source was 70%.…”

Section: Rectangular Photoreactorsmentioning

confidence: 99%

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

Eneşca

2021

Catalysts

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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.

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Intensification of a flat-plate photocatalytic reactor performances by innovative visible light modulation techniques: A proof of concept

Cited by 12 publications

References 18 publications

Use of Visible Light Modulation Techniques in Urea Photocatalytic Degradation

Use of Visible Light Modulation Techniques in Urea Photocatalytic Degradation

Visible light-driven degradation of Acid Orange 7 by light modulation techniques

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

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