Modification of Recovered Silicon from End-of-Life Photovoltaic Panels for Catalytic Reduction of Cr(VI)
As installed photovoltaic panels (PVPs) approach their End of Life (EoL), the need for a sustainable recovery plan becomes imperative. This work aims to reuse silicon from EoL PVPs as a potential catalyst/photocatalyst for wastewater treatment. PVPs were pretreated thermally. The resulting mixture w...
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MDPI AG
2022-11-01
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| author | Charalampos Pavlopoulos Konstantina Papadopoulou Minas Theocharis Petros Tsakiridis Pavlina Kousi Artin Hatzikioseyian Emmanouella Remoundaki Gerasimos Lyberatos |
| author_facet | Charalampos Pavlopoulos Konstantina Papadopoulou Minas Theocharis Petros Tsakiridis Pavlina Kousi Artin Hatzikioseyian Emmanouella Remoundaki Gerasimos Lyberatos |
| author_sort | Charalampos Pavlopoulos |
| collection | DOAJ |
| description | As installed photovoltaic panels (PVPs) approach their End of Life (EoL), the need for a sustainable recovery plan becomes imperative. This work aims to reuse silicon from EoL PVPs as a potential catalyst/photocatalyst for wastewater treatment. PVPs were pretreated thermally. The resulting mixture was separated into different fractions using a trommel screen. Recovered silicon flakes were cleaned with HΝO<sub>3</sub> and HF in order to obtain pure Si, which was then etched through a single stage Ag-assisted Chemical Etching process and decorated with Ag/Cu. Photocatalytic reduction of Cr(VI) in the presence of 5 mM citric acid was carried out in a 600 mL batch reactor irradiated by a Xenon 150 W arc lamp as well as under dark conditions. It was found that, in the presence of 1.2 g/L of Si catalyst, Cr(VI) at an initial concentration of 15 mg/L can be reduced below the detection limit (>99%), even under dark conditions, in 30–180 min, depending on the pH of the solution and the citric acid concentration. Citric acid was proved to assist the reaction in three ways: lowering the pH, increasing the solubility of the precipitate, preventing inhibition, and as sacrificial agent in photocatalysis. Irradiation, however, was shown to possibly inhibit the process if the citric acid concentration is low. |
| first_indexed | 2024-03-11T05:21:39Z |
| format | Article |
| id | doaj.art-351ecdb2f478452bad393ea3f021a6d0 |
| institution | Directory Open Access Journal |
| issn | 2813-0391 |
| language | English |
| last_indexed | 2024-03-11T05:21:39Z |
| publishDate | 2022-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Waste |
| spelling | doaj.art-351ecdb2f478452bad393ea3f021a6d02023-11-17T17:48:33ZengMDPI AGWaste2813-03912022-11-0111819410.3390/waste1010006Modification of Recovered Silicon from End-of-Life Photovoltaic Panels for Catalytic Reduction of Cr(VI)Charalampos Pavlopoulos0Konstantina Papadopoulou1Minas Theocharis2Petros Tsakiridis3Pavlina Kousi4Artin Hatzikioseyian5Emmanouella Remoundaki6Gerasimos Lyberatos7School of Chemical Engineering, National Technical University of Athens, Iroon Polytechneiou 9, Zografou, 15780 Athens, GreeceSchool of Chemical Engineering, National Technical University of Athens, Iroon Polytechneiou 9, Zografou, 15780 Athens, GreeceSchool of Mining and Metallurgical Engineering, National Technical University of Athens, Iroon Polytechneiou 9, Zografou, 15780 Athens, GreeceSchool of Mining and Metallurgical Engineering, National Technical University of Athens, Iroon Polytechneiou 9, Zografou, 15780 Athens, GreeceSchool of Mining and Metallurgical Engineering, National Technical University of Athens, Iroon Polytechneiou 9, Zografou, 15780 Athens, GreeceSchool of Mining and Metallurgical Engineering, National Technical University of Athens, Iroon Polytechneiou 9, Zografou, 15780 Athens, GreeceSchool of Mining and Metallurgical Engineering, National Technical University of Athens, Iroon Polytechneiou 9, Zografou, 15780 Athens, GreeceSchool of Chemical Engineering, National Technical University of Athens, Iroon Polytechneiou 9, Zografou, 15780 Athens, GreeceAs installed photovoltaic panels (PVPs) approach their End of Life (EoL), the need for a sustainable recovery plan becomes imperative. This work aims to reuse silicon from EoL PVPs as a potential catalyst/photocatalyst for wastewater treatment. PVPs were pretreated thermally. The resulting mixture was separated into different fractions using a trommel screen. Recovered silicon flakes were cleaned with HΝO<sub>3</sub> and HF in order to obtain pure Si, which was then etched through a single stage Ag-assisted Chemical Etching process and decorated with Ag/Cu. Photocatalytic reduction of Cr(VI) in the presence of 5 mM citric acid was carried out in a 600 mL batch reactor irradiated by a Xenon 150 W arc lamp as well as under dark conditions. It was found that, in the presence of 1.2 g/L of Si catalyst, Cr(VI) at an initial concentration of 15 mg/L can be reduced below the detection limit (>99%), even under dark conditions, in 30–180 min, depending on the pH of the solution and the citric acid concentration. Citric acid was proved to assist the reaction in three ways: lowering the pH, increasing the solubility of the precipitate, preventing inhibition, and as sacrificial agent in photocatalysis. Irradiation, however, was shown to possibly inhibit the process if the citric acid concentration is low.https://www.mdpi.com/2813-0391/1/1/6hexavalent chromium reductionphotocatalystphotovoltaic panelsilicon recoverywastewater treatment |
| spellingShingle | Charalampos Pavlopoulos Konstantina Papadopoulou Minas Theocharis Petros Tsakiridis Pavlina Kousi Artin Hatzikioseyian Emmanouella Remoundaki Gerasimos Lyberatos Modification of Recovered Silicon from End-of-Life Photovoltaic Panels for Catalytic Reduction of Cr(VI) Waste hexavalent chromium reduction photocatalyst photovoltaic panel silicon recovery wastewater treatment |
| title | Modification of Recovered Silicon from End-of-Life Photovoltaic Panels for Catalytic Reduction of Cr(VI) |
| title_full | Modification of Recovered Silicon from End-of-Life Photovoltaic Panels for Catalytic Reduction of Cr(VI) |
| title_fullStr | Modification of Recovered Silicon from End-of-Life Photovoltaic Panels for Catalytic Reduction of Cr(VI) |
| title_full_unstemmed | Modification of Recovered Silicon from End-of-Life Photovoltaic Panels for Catalytic Reduction of Cr(VI) |
| title_short | Modification of Recovered Silicon from End-of-Life Photovoltaic Panels for Catalytic Reduction of Cr(VI) |
| title_sort | modification of recovered silicon from end of life photovoltaic panels for catalytic reduction of cr vi |
| topic | hexavalent chromium reduction photocatalyst photovoltaic panel silicon recovery wastewater treatment |
| url | https://www.mdpi.com/2813-0391/1/1/6 |
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