Publications of Fouad Zouhir
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See detailOptimization of hydraulic efficiency and wastewater treatment performances using a new design of vertical flow Multi-Soil-Layering (MSL) technolgy
Latrach, Lahbib; Ouazzani, Naaila; Hejjaj, Abdessamad et al

in Ecological Engineering (2018), 117

The study gives a new method for contaminants removal from domestic wastewater using a novel design of Multi-Soil-Layering (MSL) eco-technology. Two MSL reactors were built and operated under laboratory ... [more ▼]

The study gives a new method for contaminants removal from domestic wastewater using a novel design of Multi-Soil-Layering (MSL) eco-technology. Two MSL reactors were built and operated under laboratory conditions: astandard and modified MSL design(S-MSL andM-MSL). Atracer testusing KClindicated varyingdegrees of dispersion, short-circuiting, dead space, effective volume ratio and hydraulic efficiency in two MSL reactors. The new MSL design was found to be most effective in improving hydrodynamic flow conditions. The M-MSL reactor increased the mean HRT from 15.79 to 22.07h, and decreased the dead space rate from 38% to 8%. The early arrival of the distribution peak, indicator of short-circuiting, was mainly noted in the case of S-MSL RTD which is around 57% of the nominal HRT. A high dead space rate was found to occur in the S-MSL reactor, and produced a poor hydraulic performance. The large difference between the nominal and mean HRT confirms the presence of zones of stagnation in the S-MSL system. The new MSL design increased the effective volume ratio from 0.62 to 0.92. The hydraulic efficiency was increased from 0.26 to 0.84 and reached a good level (λ≥0.75) highlighting the excellent hydraulic performance of the M-MSL design. Obtained results revealed that M-MSL had an optimal hydraulic profile and enhanced sanitary and physicochemical performances compared to S-MSL. The mean log reduction of total coliforms, fecal coliforms and fecal streptococci was increased from 1.25, 1.26 and 1.15 log units for the S-MSL to 2.36, 2.38 and 2.11 log units for the M-MSL reactor. Both MSL reactors achieved high and satisfactory TSS and organics removal. The M-MSL reactor accomplished a 92% removal of TN, while the S-MSL achieved a slightly less effective result. The M-MSL reactor was also found to be more efficient in reducing TP by 98% compared to a removal rate of 76% in the S-MSL reactor. Therefore, the new design of MSL eco-technology could be adopted as an alternative to the current design for efficient domestic wastewater treatment. [less ▲]

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See detailUse of bacteria and yeast strains for dairy wastewater treatment
Keffala, Chéma ULiege; Zouhir, Fouad ULiege; Ben Hadj Abdallah et al

in International Journal of Research in Engineering and Technology (2017), 6(4), 108-113

The present investigation was carried out to study the biodegradation of dairy effluent collected from a regional dairy industry, in Tunisia, by using selected aerobic microbial and yeast isolates. The ... [more ▼]

The present investigation was carried out to study the biodegradation of dairy effluent collected from a regional dairy industry, in Tunisia, by using selected aerobic microbial and yeast isolates. The predominant microorganisms : Candida albicans, Candida krusei, Lactobacillus plantarum and Lactobacillus casei isolated from activated sludge pond of the dairy plant were used. Biodegradation tests were performed in batch into Erlenmeyer flasks containing collected dairy wastewater samples. Two sets of experiments were carried out in duplicate. For the first set of experiments, each bacteria and yeast strain was used for the preparation of four inoculums composed of single culture. These inoculums are added separately in the test samples with a concentration of 1% (v/v). For the second set of experiments, three inoculums rate (1, 5 and 10% (v/v)) were tested. A bacteria and yeast mixed culture were added separately in the test samples. A variable amount of COD, proteins and total sugars reduction was observed with individual and mixture isolates after 25 days treatment period. The chemical oxygen demand (COD) has received reduction varying between 51.6 and 71.6% with individual isolates at 1% (v/v) inoculum rate, while bacterial mixed culture and yeast mixed culture showed reduction up to 75.8 and 70.7% respectively, at 1% (v/v) inoculum rate. Isolates with inoculum rate of 5% (v/v) proved to be most efficient in the treatment of effluent. The highest reduction of total sugar content was obtained by yeast consortium while the highest reduction of protein content was obtained by bacteria consortium. [less ▲]

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See detailModélisation d'une filière de traitement des eaux usées - Chenal Algal à haut Rendement
Zouhir, Fouad ULiege

Doctoral thesis (2008)

Le Chenal Algal à Haut Rendement (CAHR) est un procédé de traitement des eaux usées qui constitue une alternative économique et efficace par rapport aux autres systèmes de traitement intensifs ... [more ▼]

Le Chenal Algal à Haut Rendement (CAHR) est un procédé de traitement des eaux usées qui constitue une alternative économique et efficace par rapport aux autres systèmes de traitement intensifs généralement trouvé en Europe (Boues activées, Lit bactérien, Biodisque…), semblant pallier à tous les problèmes cités précédemment. Il s’agit en fait d’une technique basée sur une symbiose entre les bactéries et les algues, dont le but est d’accélérer le processus d’épuration en favorisant la production algale. Outre l’épuration et la réutilisation de l’eau épurée, le CAHR est donc destiné à la production d’une biomasse algale valorisable en extraits algaux à haute valeur ajoutée (destinés à l’industrie cosmétique) et en aliments pour les animaux. La preuve a été faite que, sous des climats adaptés, et quand ils sont bien intégrés, bien conçus et opérationnels, les CAHR permettent de produire un effluent de qualité égale, voire supérieure à d’autres procédés d’épuration, à un coût bien moindre en terme d’investissement et d’exploitation et avec un minimum de contraintes. Le CAHR est un système néanmoins complexe car il fait intervenir de nombreuses composantes, qu’il faut maîtriser si l’on veut atteindre les objectifs multiples cités ci-dessus. Dans ce contexte, la modélisation constitue un outil quasi incontournable en termes de gestion du système. Dans cette thèse, nous avons abordé 3 axes importants pour une bonne gestion d’une station d’épuration en vue d’une optimisation des performances épuratoires et aussi une économie d’énergie. Il s’agit une étude hydrodynamique, une étude des transferts gazeux (O2, CO2…) et une étude de modélisation. Ces résultats sont motivants pour la suite du travail. Dans une perspective de calage et de validation du modèle, il sera nécessaire de récolter le maximum de données (enregistrements en continues (O2, pH, turbidité, …) et analyses courantes sur le chenal de Saada (vraie grandeur) pour un meilleur ajustement des paramètres du modèle. Mais il sera utile de mener une analyse de sensibilité du modèle, dans le but d’identifier les paramètres les plus sensibles. Ce sont ces derniers qui peuvent guider l’utilisateur dans la collecte d’informations ciblées sur le terrain et dans le processus de calibrage du modèle. [less ▲]

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