[ Influence de la granulométrie sur la durabilité du Lit de Séchage à Ecoulement Non Saturé (LSENS) en traitement de boues de vidange des fosses septiques ]
Volume 29, Issue 2, May 2020, Pages 275–286
Ténéna Martial YEO1, Kinanpara KONE2, Théophile Gnagne3, and Yves Kotchi BONY4
1 Unité de Formation et de Recherche en Environnement, Université JEAN LOROUGNON GUEDE, BP 150 Daloa, Côte d’Ivoire
2 Unité de Formation et de Recherche en Environnement, Université JEAN LOROUGNON GUEDE, BP 150 Daloa, Côte d’Ivoire
3 Laboratory of Geosciences and Environment, UFR of Sciences and Environment Management, University Nangui ABROGOUA, Abidjan, Côte d'Ivoire
4 Unité de Formation et de Recherche en Environnement, Université JEAN LOROUGNON GUEDE, BP 150 Daloa, Côte d’Ivoire
Original language: French
Copyright © 2020 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.
Non-Saturated Flow Drying Beds permit the effective treatment of septic tank discharge sludge. However, they are vulnerable to clogging. To ensure the sustainability of this technology, through the choice of a suitable filter bed, an unsaturated flow model coupled with the variation of the biofilm has been developed. Calibration, validation and comparison of model simulation results and experimental results were performed on the basis of the NASH criterion. The simulations covered three types of sand: fine sand, medium sand and coarse sand. The results show that the maximum organic load applicable is 24.7 mgO2 / cm2 / day at the fine sand, 43.3 mgO2 / cm2 / day at the medium sand and 31.6 mgO2 / cm2 / day at the level of the sand coarse sand. Then, the Chemical Oxygen Demand removal yield is 92 % at the medium sand level versus 73 % for the coarse sand. Finally, medium sand is less vulnerable to clogging (91.3 %) than fine sand (95.45 %). So, of the three types of sand, it is the average sand that is best suited for the treatment of sludge septic tanks by Non-Saturated Flow Drying Beds. However, when the average sand is not available, the developed model makes it possible to fix the operating conditions and the purification yields of the available sand.
Author Keywords: Biofilm, faecal sludge, organic load, clogging, porosity, simulation.
Volume 29, Issue 2, May 2020, Pages 275–286
Ténéna Martial YEO1, Kinanpara KONE2, Théophile Gnagne3, and Yves Kotchi BONY4
1 Unité de Formation et de Recherche en Environnement, Université JEAN LOROUGNON GUEDE, BP 150 Daloa, Côte d’Ivoire
2 Unité de Formation et de Recherche en Environnement, Université JEAN LOROUGNON GUEDE, BP 150 Daloa, Côte d’Ivoire
3 Laboratory of Geosciences and Environment, UFR of Sciences and Environment Management, University Nangui ABROGOUA, Abidjan, Côte d'Ivoire
4 Unité de Formation et de Recherche en Environnement, Université JEAN LOROUGNON GUEDE, BP 150 Daloa, Côte d’Ivoire
Original language: French
Copyright © 2020 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
Non-Saturated Flow Drying Beds permit the effective treatment of septic tank discharge sludge. However, they are vulnerable to clogging. To ensure the sustainability of this technology, through the choice of a suitable filter bed, an unsaturated flow model coupled with the variation of the biofilm has been developed. Calibration, validation and comparison of model simulation results and experimental results were performed on the basis of the NASH criterion. The simulations covered three types of sand: fine sand, medium sand and coarse sand. The results show that the maximum organic load applicable is 24.7 mgO2 / cm2 / day at the fine sand, 43.3 mgO2 / cm2 / day at the medium sand and 31.6 mgO2 / cm2 / day at the level of the sand coarse sand. Then, the Chemical Oxygen Demand removal yield is 92 % at the medium sand level versus 73 % for the coarse sand. Finally, medium sand is less vulnerable to clogging (91.3 %) than fine sand (95.45 %). So, of the three types of sand, it is the average sand that is best suited for the treatment of sludge septic tanks by Non-Saturated Flow Drying Beds. However, when the average sand is not available, the developed model makes it possible to fix the operating conditions and the purification yields of the available sand.
Author Keywords: Biofilm, faecal sludge, organic load, clogging, porosity, simulation.
Abstract: (french)
Les Lits de Séchage à Ecoulement Non Saturé permettent le traitement efficace des boues de vidange des fosses septiques. Cependant, ils sont vulnérables au colmatage. Pour garantir la durabilité de cette technologie, à travers le choix d’un massif filtrant approprié, un modèle d’écoulement en milieu non saturé couplé avec la variation du biofilm a été développé. Le calage, la validation et la comparaison des résultats de simulation du modèle et des résultats expérimentaux ont été faits sur la base du critère de NASH. Les simulations ont porté sur trois types de sables : un sable fin, un sable moyen et un sable grossier. Les résultats montrent que la charge organique maximale applicable est de 24,7 mgO2/cm2/j au niveau du sable fin, 43,3 mgO2/cm2/j au niveau du sable moyen et 31,6 mgO2/cm2/j au niveau du sable grossier. Ensuite, le rendement d’élimination de la Demande Chimique en Oxygène est de 92% au niveau du sable moyen contre 73% pour le sable grossier. Enfin, le sable moyen est moins vulnérable au colmatage (91,3%) que le sable fin (95,45%). Ainsi donc, des trois types de sable, c’est le sable moyen qui est le mieux approprié pour le traitement des boues de vidange des fosses septiques par les Lits de Séchage à Ecoulement Non Saturé. Toutefois, lorsque le sable moyen n’est pas disponible, le modèle développé permet de fixer les conditions de fonctionnement et les rendements épuratoires du sable disponible.
Author Keywords: Biofilm, boues de vidange, charge organique, colmatage, porosité, simulation.
How to Cite this Article
Ténéna Martial YEO, Kinanpara KONE, Théophile Gnagne, and Yves Kotchi BONY, “Influence of granulometry on the durability of the Non Satured Flow Drying Bed (NSFDB) in the treatment of septic tank sludge,” International Journal of Innovation and Applied Studies, vol. 29, no. 2, pp. 275–286, May 2020.
