[ Amélioration de la désinfection solaire de l’eau par la photosensibilisation des extraits de plantes ]
Volume 40, Issue 4, October 2023, Pages 1240–1245
Teddy Makuba SUNDA1 and Nicolas Kalulu Muzele TABA2
1 Université de Kinshasa, Faculté des Sciences, Département de Chimie, Laboratoire de Chimie Organique et d’Energétique, BP 190, Kinshasa XI, RD Congo
2 Université de Kinshasa, Faculté des Sciences et Technologies, Département de Chimie et Industrie, Laboratoire de Chimie Organique et d’Energétique, BP 190, Kinshasa XI, RD Congo
Original language: French
Copyright © 2023 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The present study aimed to improve the solar water disinfection by the photosensitization of coumarin extracts of some plants of the Rutaceae family (Citrus reticulata, Citrus aurantium and Citrus maxima). The results found in this work show an inhibition of around 7% of faecal coliforms after 15 minutes of exposure for solar disinfection. An inhibition of 17 % is noticed after 30 minutes of exposure. On the other hand, for water treated and exposed to the sun, an inhibition of around 90% is noticed for all the extracts after 30 minutes of exposure. Complete inhibition is recorded after 60 minutes of exposure. These results show that the plant extracts used improve significantly the solar disinfection of water. The photosensitizing activity observed in these extracts is due to the presence of coumarins. These molecules, in the presence of light, absorb energy and pass from the ground state to the excited state. Returning to the ground state, the stored energy is transferred to the oxygen, which then passes from the ground state, triplet, to the excited state, singlet, and inhibits the microorganisms present in the water.
Author Keywords: Photosensitization, coumarin extracts, singlet oxygen, faecal coliforms, solar disinfection.
Volume 40, Issue 4, October 2023, Pages 1240–1245
Teddy Makuba SUNDA1 and Nicolas Kalulu Muzele TABA2
1 Université de Kinshasa, Faculté des Sciences, Département de Chimie, Laboratoire de Chimie Organique et d’Energétique, BP 190, Kinshasa XI, RD Congo
2 Université de Kinshasa, Faculté des Sciences et Technologies, Département de Chimie et Industrie, Laboratoire de Chimie Organique et d’Energétique, BP 190, Kinshasa XI, RD Congo
Original language: French
Copyright © 2023 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
The present study aimed to improve the solar water disinfection by the photosensitization of coumarin extracts of some plants of the Rutaceae family (Citrus reticulata, Citrus aurantium and Citrus maxima). The results found in this work show an inhibition of around 7% of faecal coliforms after 15 minutes of exposure for solar disinfection. An inhibition of 17 % is noticed after 30 minutes of exposure. On the other hand, for water treated and exposed to the sun, an inhibition of around 90% is noticed for all the extracts after 30 minutes of exposure. Complete inhibition is recorded after 60 minutes of exposure. These results show that the plant extracts used improve significantly the solar disinfection of water. The photosensitizing activity observed in these extracts is due to the presence of coumarins. These molecules, in the presence of light, absorb energy and pass from the ground state to the excited state. Returning to the ground state, the stored energy is transferred to the oxygen, which then passes from the ground state, triplet, to the excited state, singlet, and inhibits the microorganisms present in the water.
Author Keywords: Photosensitization, coumarin extracts, singlet oxygen, faecal coliforms, solar disinfection.
Abstract: (french)
La présente étude visait l’amélioration de la désinfection solaire de l’eau par la photosensibilisation des extraits coumariniques de quelques plantes de la famille de Rutacées (Citrus reticulata, Citrus aurantium et Citrus maxima). Les résultats trouvés dans ce travail montrent une inhibition de l’ordre de 7 % des coliformes fécaux après 15 minutes d’exposition pour la désinfection solaire. Celle-ci passe à 17 % après 30 minutes d’ensoleillement. Par contre, pour l’eau traitée et exposée au soleil, nous avons noté une inhibition de l’ordre de 90% pour tous les extraits après 30 minutes d’exposition. L’inhibition complète est enregistrée après 60 minutes d’exposition. Ceci montre que les extraits de plantes utilisés améliorent sensiblement la désinfection solaire de l’eau. L’activité photosensibilisatrice remarquée dans ces extraits est due à la présence des coumarines. Celles-ci en présence de lumière absorbent l’énergie et passent de l’état fondamental à l’état excité. En revenant à l’état fondamental, l’énergie emmagasinée est transférée à l’oxygène qui passe dès lors de l’état fondamental, triplet, à l’état excité, singulet, tout en inhibant les coliformes fécaux présents dans l’eau.
Author Keywords: Photosensibilisation, extraits coumariniques, oxygène singulet, coliformes fécaux, désinfection solaire.
How to Cite this Article
Teddy Makuba SUNDA and Nicolas Kalulu Muzele TABA, “Improvement of solar water disinfection by the photosensitization of plant extracts,” International Journal of Innovation and Applied Studies, vol. 40, no. 4, pp. 1240–1245, October 2023.
