23 research outputs found

    Traitement des margines par Ă©lectrocoagulation avec des Ă©lectrodes plates en aluminium

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    Les effluents liquides des huileries d’olive (margines) produits par le processus d’extraction d’huile d’olive sont les principaux dĂ©chets nuisibles de cette industrie. La caractĂ©risation de ces effluents suivie de l’élimination de la matiĂšre organique (demande chimique en oxygĂšne (DCO), des polyphĂ©nols totaux, de la matiĂšre en suspension (MES) et de la couleur), de la matiĂšre minĂ©rale (phosphates et azote ammoniacal) et des mĂ©taux lourds (zinc et fer) ont Ă©tĂ© expĂ©rimentalement Ă©tudiĂ©es Ă  l’aide de la technique d’électrocoagulation en utilisant des Ă©lectrodes en aluminium. Il est constatĂ© que l’augmentation du temps d’électrolyse et de la tension Ă©lectrique amĂ©liore le traitement de façon significative. Toutefois, la consommation simultanĂ©e d’énergie et des Ă©lectrodes a Ă©tĂ© observĂ©e. Les rĂ©sultats de ces analyses ont montrĂ© que les margines diluĂ©es cinq fois sont des effluents Ă  pH acides (4,2), trĂšs chargĂ©s en matiĂšre organique (20 000 mg‱L‑l de Demande Chimique en OxygĂšne (DCO)), en sels (ConductivitĂ© Électrique (C.E) = 3,6 mS‱cm‑1), en azote ammoniacal (NH4+) (32 mg‱L‑1), en orthophosphates (PO43-) (22 mg‱L‑1). Elles contiennent Ă©galement des quantitĂ©s apprĂ©ciables de mĂ©taux lourds, notamment le zinc (3,69 mg‱L‑1) et le fer (13,80 mg‱L‑1).L’évolution des paramĂštres physico-chimiques au cours du traitement par Ă©lectrocoagulation montre que dans les conditions d’un temps d’électrolyse de 15 minutes et d’une tension Ă©lectrique de 20 volts (correspond Ă  250 A‱m‑2), la dĂ©coloration des margines diluĂ©es cinq fois est comprise entre 96-99 %, la rĂ©duction de la Demande Chimique en OxygĂšne (DCO) est d’environ 80-85 %, la rĂ©duction des polyphĂ©nols totaux est d’environ 75-80 %, l’élimination des particules colloĂŻdales (MatiĂšre En Suspension (MES)) peut atteindre 7-8 kg‱m‑3, la rĂ©duction des orthophosphates est 94-99 %, la rĂ©duction de l’ammonium est 80-85 %,la rĂ©duction du zinc est 70-75 %, la rĂ©duction du fer est 71-76 %, la masse perdue des Ă©lectrodes est 0,6-0,7 kg‱m‑3 et l’énergie consommĂ©e est 12‑14 kWh‱m‑3. Ces niveaux opĂ©rationnels optimaux permettent d’avoir une bonne dĂ©gradation des margines.Olive mill wastewater (OMWW) generated by the olive oil extraction process is the main waste product of this industry. These effluents have been characterized, followed by an experimental study of the elimination of organic matter (chemical oxygen demand (COD), phenolic compounds, suspended solids (SS) and colour), mineral matter (phosphate and ammonium nitrogen) and heavy metals (zinc and iron) using an electrocoagulation technique with aluminum electrodes. It was found that an increase in electrolysis time and voltage improved treatment significantly. However, a simultaneous increase in electrode and energy consumption was observed.The results of these analyses showed that the olive mill wastewater (OMWW) effluent, diluted five times, is acidic (pH 4.2), has a very high organic matter concentration (chemical oxygen demand (COD) 20,000 g‱L‑1) and is high in salts (Electric Conductivity E.C = 3.6 mS‱cm‑1), ammonium nitrogen (NH4+) (32 mg‱L‑1) and orthophosphate (PO43‑) (22 mg‱L‑1). The OMWW also contains considerable amounts of heavy metals, in particular zinc (3.69 mg‱L‑1) and iron (13.80 mg‱L‑1).The trend in physicochemical parameters during the electrocoagulation treatment shows that, after 15 minutes of electrolysis using an electrical voltage of 20 volts (corresponds to 250 A‱m‑2), the discolouration of the OMWW, diluted five times, lay between 96-99%, the reduction of the chemical oxygen demand (COD) was approximately 80-85%, the reduction of phenolic compounds was approximately 75‑80%, the elimination of colloidal material (suspended solids) reached 7-8 kg‱m‑3, the reduction of orthophosphates was 94-99% and the reduction of ammonium was 80-85%. The reduction of zinc was 70-75%, the reduction of iron was 71-76%, the electrode consumption was 0.6-0.7 kg‱m‑3 and the amount of energy consumed was 12-14 kWh‱m‑3. Under these optimal operational conditions, acceptable degradation of the OMWW was achieved

    Widespread occurrence of non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase among gram-positive bacteria

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    The non-phosphorylating glyceraldehyde 3-phosphate dehydrogenase (GAPDHN, NADP+-specific, EC is present in green eukaryotes and some Streptococcus strains. The present report describes the results of activity and immunoblot analyses, which were used to generate the first survey of bacterial GAPDHN distribution in a number of Bacillus, Streptococcus and Clostridium strains. Putative gapN genes were identified after PCR amplification of partial 700-bp sequences using degenerate primers constructed from highly conserved protein regions. Alignment of the amino acid sequences of these fragments with those of known sequences from other eukaryotic and prokaryotic GAPDHNs, demonstrated the presence of conserved residues involved in catalytic activity that are not conserved in aldehyde dehydrogenases, a protein family closely linked to GAPDHNs. The results confirm that the basic structural features of the members of the GAPDHN family have been conserved throughout evolution and that no identity exists with phosphorylating GAPDHs. Furthermore, phylogenetic trees generated from multiple sequence alignments suggested a close relationship between plant and bacterial GAPDHN families. [Int Microbiol 2005; 8(4):251-258

    Screening of antibacterial and antifungal activities in green and brown algae from the coast of Sidi Bouzid (El Jadida, Morocco)

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    Six organic extracts prepared with different solvents (methanol, acetone, hexane, chloroform and dichloromethane-methanol) and aqueous extract of 27 species of marine algae belonging to the Chlorophyta and Phaeophyta were studied for antibacterial and antifungal activities against pathogenic microorganism: eight Gram-positive bacteria: Bacillus cereus, Bacillus thuringiensis, Bacillus subtillus, Clostridium sporogenes, Staphylococcus aureus, Mycobacterium smegmatis, Streptococcus faecalis and Bacillus sp, two Gram-negative bacteria: Escherichia coli and Pseudomonas sp and against fungi: Candida tropicalis and Cryptococcus neoformans. The best activity was observed in methanolic extract followed by acetonic extract and that prepared with methanol–dichloromethane. Of the 27 species tested, those belonging to Phaeophyceae were the most active in comparison with Chlorophyceae. The Gram-positive bacteria presented a sensibility superior to the Gram-negative and S. aureus ssp. aureus was the more sensitiveKey words: Macroalgae, algal extracts, antibacterial activity, antifungal activity, pathogenic microorganism


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    Objective: The objective of our work was to search for a new biopesticides extracted from marine algae found on the coast of El Jadida, Sidi Bouzid-Morocco.Methods: Extracts of 17 species of algae (Rhodophyceae, Rhodophyceae, Chlorophyceae) collected from the coast of El Jadida, Morocco, were tested for their antibacterial activity against the bacterial strain Erwinia chrysanthemi that causes soft rot in potato (Solanum tuberosum L.).Results: Of the 17 species studied, those belonging to the Phaeophyceae and Rhodophyceae were the most active, while Chlorophyceae have a low inhibition. Maximum inhibition of the growth of Erwinia chrysanthemi was obtained by extracts prepared in dichloromethane and methanol, and by dichloromethane extract. No activity was observed in the aqueous extracts.Conclusion: The results obtained in this study clearly indicated that macroalgae from the coast of Sidi Bouzid can be used in the treatment of plant diseases especially soft rot of potato.Â

    Assessment of performance wastewater treatment by infiltration-percolation: a case study

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    The recycling of wastewater is felt like a need, on the one hand to protect the receiving mediums and on the other hand, to be re-used for various uses (refill of the groundwater, irrigation
.). To allow the development of the treatment of wastewater, the infiltration percolation can in this context, to represent an interesting alternative. This technique of purification combined with the Anaerobic Engine with Submerged Bacterial Bed (RALBI) developed at the point by laboratory BIOMARE of the Faculty of Science of El Jadida has for increasing the performances of treatment of the known as engine. The results of the complementary treatment by the infiltration-percolation made it possible to remove the effluent from engine RALBI from its suspended matter and to decrease its organic, nitrogen, and phosphor load and of its microbial flora. The averages of results of specific analyses are all in lower part of the thresholds of reference. Keywords: wastewater, treatment, infiltration-percolation, RALBI, bioreactor, El Jadida, Morocc

    Treatment of domestic wastewater by anaerobic denitrification: Influence of the type of support media on the production of extracellular polymer substances

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    Eighteen Erlenmeyer flask containing six different support media [pozzolan, polyvinyl chloride1 (PVC1), polyvinyl chloride2 (PVC2), foam, polyethylene terephthalate (PET) and polystyrene (PS)] were subject to identical volumetric organic loadings and hydraulic retention time in treating synthetic protein ± carbohydrate waste. The objective was to examine the influence of support media on performance of anaerobic denitrification and retention and their resulting impact on system performance and failure. According to the results relative to every control support media, it was noticed that the best support media were the ones in PVC1 and PVC2, with successive reduction rates of 68.33 and 61.93% for chemical oxygen demand (COD), and 55 and 49% for nitrate. On the other hand, in two submerged anaerobic biofilter reactor packed with the support media of PVC1 and PVC2, the reactor with PVC1 media exhibited 89.93% COD and 78.75% nitrate removal efficiency attributable to its higher production of EPSp and EPSc.Key words: Wastewater, anaerobic biofilm, extracellular polymeric substances (EPS), extraction, support media

    Fucus spiralis extract and fractions: Anticancer and pharmacological potentials

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    Purpose: Sea macroalgae are an important source of biologically highly valuable compounds. The main aim of this study was to investigate the in vitro anticancer properties and chemical composition of the dichloromethane-methanol extract and three fractions of the Fucus spiralis from coastline of Morocco. Methods: Fractions were made from dichloromethane: methanol (1:1) extract of Fucus spiralis: petroleum-ether, ethyl-acetate and n-butanol. Extract and fractions were screened for in vitro cytotoxicity by MTT assay against human cervical adenocarcinoma (HeLa), colorectal adenocarcinoma (LS-174T), lung carcinoma (A549), and normal human lung fibroblasts (MRC-5). Cell cycle distribution of the HeLa cells was evaluated using flow cytometry. Acridine orange (AO)-ethidium bromide (EB) staining was used to assess morphological changes of HeLa cells under fluorescence microscope. Anti-migration and anti-angiogenic properties were investigated using scratch and tube formation assays against human endothelium-derived permanent EA.hy926 cell line. Antidiabetic activity was tested using anti-α-glucosidase assay. Antimicrobial effect was tested using micro- dilution method. Results: Petroleum-ether fraction ĐŸf Fucus spiralis rich in fatty acids exerted the highest cytotoxicity against HeLa cells. Ethyl-acetate and petroleum-ether fractions induced the highest accumulation of the HeLa cells in sub-G1 and G2/M phases. Extract and fractions showed proapoptotic effect on HeLa cells under fluorescent microscope. They exhibited antimigratory and antiangiogenic effects in vitro. IC50 value for α-glucosidase inhibitory activity was much stronger than standard acarbose. n-Butanol fraction exerted the highest antibacterial and antifungal activity. Conclusions: The investigation of various biological activities of the extract and fractions obtained from Fucus spiralis may suggest a promising anticancer and pharmacological potential of this edible macroalga

    Rejets d’abattoir : caractĂ©risation et Ă©tude d’impact sur le milieu marin rĂ©cepteur

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    The annual rated capacity of the El Jadida’s slaughterhouse (Morocco) is 1 300 tons of carcasses producing approximately 590 tons of wastes/year. Considering its proximity with the sea, the effluent of this slaughterhouse is rejected there directly without any treatment. This work relates to the characterization of the total effluent gross generated by this slaughterhouse and the study of its impact on the quality of the receiving marine environment. The results of the characterization show that the studied effluent is rich in organic matter (COD: 170 g O2 per l) and in indicating fecal bacteria (FC: 7.108 cfu per ml and FS: 5.107 cfu per ml). The impact study shows that the vicinity of the collector of the slaughterhouse has an evolution towards a eutrophic state which results in an abundant development of algae (Enteromorpha intestinalis and Ulva lactuca) and a higher bacterial contamination of sea water, sediments and shells.La capacitĂ© nominale annuelle de l’abattoir de la ville d’El Jadida (Maroc) est de 1 300 tonnes de carcasses abattues produisant environ 590 tonnes de dĂ©chets/an. SituĂ© Ă  proximitĂ© de la mer, cet abattoir y rejette ses effluents directement sans aucun traitement. La prĂ©sente Ă©tude a pour objectif la caractĂ©risation des effluents bruts gĂ©nĂ©rĂ©s par cet abattoir et l’étude de leur impact sur la qualitĂ© du milieu marin rĂ©cepteur. Les rĂ©sultats obtenus montrent que l’effluent Ă©tudiĂ© est riche en matiĂšre organique (DCO : 170 g d’O2/l) et en bactĂ©ries indicatrices de contamination fĂ©cale (CF : 7.108 ufc/ml et SF : 5.107 ufc/ml). L’étude montre qu’au voisinage du collecteur de l’abattoir, on a une Ă©volution vers un Ă©tat eutrophe qui se traduit par un dĂ©veloppement abondant d’algues (Enteromorpha intestinalis et Ulva lactuca) et une forte contamination bactĂ©rienne de l’eau de mer, des sĂ©diments et des coquillages

    Simultaneous nitrate and organic matter removal from a dairy effluent by biodenitrification

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    In order to study the simultaneous removal of nitrate and organic matter from a dairy effluent containing 670 mg∙L-1 of nitrate (NO3--N) and 5 760 mg∙L-1 of dissolved chemical oxygen demand (CODd), denitrification in a laboratory scale bioreactor consisting of an immersed bacterial bed colonized by an heterotrophic denitrifying flora (HDF) selected for NO3- reduction, COD consumption and adapted to grow on an effluent produced by a dairy industry was investigated. The obtained results indicated that at the optimal conditions of temperature (30°C), pH (7), COD/NO3--N ratio (5), the operation lasted 108h with total reduction of nitrate in 72h, no nitrite accumulation, and 92% of soluble COD removal in 96h. This indicates that the biodenitrification was accompanied with a high efficiency of matter organic removal as an electron donor, and thereby satisfies the applicable standards.Dans le but d’étudier la biodĂ©nitrification d'un effluent industriel laitier Ă  fortes concentrations en nitrates (670 mg∙L-1 de N-NO3-) et en matiĂšre organique biodĂ©gradable (5 760 mg∙L-1 de DCO soluble), un procĂ©dĂ© de type lit bactĂ©rien immergĂ© (fonctionnant en mode continu et colonisĂ© par une flore hĂ©tĂ©rotrophe dĂ©nitrifiante) a Ă©tĂ© mis en oeuvre au laboratoire BIOMARE de la FacultĂ© des Sciences de l’UniversitĂ© Chouaib Doukkali d’El Jadida (Maroc). Lorsque le procĂ©dĂ© fonctionne dans des conditions optimales (pH 7, tempĂ©rature = 30 °C, rapport massique DCO/N-NO3- = 5), des taux d’abattement des nitrates de l’ordre de 100 % sans accumulation de nitrites, couplĂ©s Ă  l’enlĂšvement de 92 % de la DCO soluble ont Ă©tĂ© obtenus au bout de 72 h et 96 h respectivement, ce qui permet de respecter les normes en vigueur pour ces deux paramĂštres