In this paper, the effect of light modulation on photocatalytic ceftriaxone (CEF) degradation in aqueous solution was investigated. The experimental set-up consisted of a fixed bed photocatalytic reactor with a flat plate geometry and visible LEDs for irradiation. Fe-N-codoped TiO2 photocatalyst was immobilized on a polystyrene plate (PS) by solvent casting method to achieve a structured photocatalyst (Fe-N-TiO2/PS), which was loaded in the photoreactor. Raman and UV–Vis diffuse reflectance spectroscopy confirmed the presence of Fe-N-TiO2 on the PS surface and its uniform distribution on the polymer support. Various LEDs dimming techniques were tested with fixed and variable duty-cycle values. In particular, the following modulations were used: fixed duty-cycle (FD), sinusoidal variable duty-cycle (S-VD), triangular variable duty-cycle (T-VD), square wave variable duty-cycle (SW-VD), saw-tooth variable duty-cycle (ST-VD), pulse variable duty-cycle (P-VD), and pseudo-sinusoidal variable duty-cycle (PS-VD). The optimal light modulation was the S-VD, with an average fed current between 25 and 75 mA and a period of 30 s. Indeed, by using S-VD modulation, the highest value of the apparent CEF degradation kinetic constant (resulting 0.0082 min−1) and the highest total organic carbon (TOC) removal (70 %) were achieved. By comparing the electric energy consumption (EE/O) with S-VD modulation used in this work with those found in other literature studies dealing with the photocatalytic ceftriaxone degradation, a significant decrease of EE/O was evidenced. Moreover, toxicity test showed that the photocatalytic treatment allowed to significantly reduce the toxicity of CEF solution when compared to untreated effluent.

Influence of visible light LEDs modulation techniques on photocatalytic degradation of ceftriaxone in a flat plate reactor / Morante, Nicola; Tammaro, Olimpia; Albarano, Luisa; De Guglielmo, Luca; Oliva, Nunzio; Sacco, Olga; Mancuso, Antonietta; Castellino, Micaela; Sannino, Diana; Femia, Nicola; Lofrano, Giusy; Libralato, Giovanni; Esposito, Serena; Vaiano, Vincenzo. - In: CHEMICAL ENGINEERING JOURNAL. - ISSN 1385-8947. - 482:(2024). [10.1016/j.cej.2024.149175]

Influence of visible light LEDs modulation techniques on photocatalytic degradation of ceftriaxone in a flat plate reactor

Albarano, Luisa;Lofrano, Giusy;Libralato, Giovanni;
2024

Abstract

In this paper, the effect of light modulation on photocatalytic ceftriaxone (CEF) degradation in aqueous solution was investigated. The experimental set-up consisted of a fixed bed photocatalytic reactor with a flat plate geometry and visible LEDs for irradiation. Fe-N-codoped TiO2 photocatalyst was immobilized on a polystyrene plate (PS) by solvent casting method to achieve a structured photocatalyst (Fe-N-TiO2/PS), which was loaded in the photoreactor. Raman and UV–Vis diffuse reflectance spectroscopy confirmed the presence of Fe-N-TiO2 on the PS surface and its uniform distribution on the polymer support. Various LEDs dimming techniques were tested with fixed and variable duty-cycle values. In particular, the following modulations were used: fixed duty-cycle (FD), sinusoidal variable duty-cycle (S-VD), triangular variable duty-cycle (T-VD), square wave variable duty-cycle (SW-VD), saw-tooth variable duty-cycle (ST-VD), pulse variable duty-cycle (P-VD), and pseudo-sinusoidal variable duty-cycle (PS-VD). The optimal light modulation was the S-VD, with an average fed current between 25 and 75 mA and a period of 30 s. Indeed, by using S-VD modulation, the highest value of the apparent CEF degradation kinetic constant (resulting 0.0082 min−1) and the highest total organic carbon (TOC) removal (70 %) were achieved. By comparing the electric energy consumption (EE/O) with S-VD modulation used in this work with those found in other literature studies dealing with the photocatalytic ceftriaxone degradation, a significant decrease of EE/O was evidenced. Moreover, toxicity test showed that the photocatalytic treatment allowed to significantly reduce the toxicity of CEF solution when compared to untreated effluent.
2024
Influence of visible light LEDs modulation techniques on photocatalytic degradation of ceftriaxone in a flat plate reactor / Morante, Nicola; Tammaro, Olimpia; Albarano, Luisa; De Guglielmo, Luca; Oliva, Nunzio; Sacco, Olga; Mancuso, Antonietta; Castellino, Micaela; Sannino, Diana; Femia, Nicola; Lofrano, Giusy; Libralato, Giovanni; Esposito, Serena; Vaiano, Vincenzo. - In: CHEMICAL ENGINEERING JOURNAL. - ISSN 1385-8947. - 482:(2024). [10.1016/j.cej.2024.149175]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/954811
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