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Thirty-two strains isolated from olive oil production plants were screened for their tolerance to the polyphenols and their ability to grow in olive oil mill wastewaters (OMW). An Ascomycete isolate that grew best on OMW was selected for further study to evaluate its effect on removal of organic pollutants, phenolic compounds and OMW toxicity. This strain was identified by DSMZ as Aspergillus niger van Tieghem. The growth of Aspergillus niger van Tieghem on stored OMW decreased pH and led to the reduction of phenolic compounds with a resultant discoloration of OMW and significant reduction of chemical oxygen demand (COD), in proportion to the dilution of OMW. The reduction of the COD, phenolics and color exceeded 50%. Tannase, the enzyme detected in the growth medium of Aspergillus niger van Tieghem was produced during primary metabolic growth. The maximal enzyme activity attaining 0.68 EU/ml was achieved in 3rd days of cultivation. The phytotoxicity of the stored OMW was reduced to about 40% after 4 days' incubation with Aspergillus niger van Tieghem.

Cet article est diffusé et préservé par Érudit. , la réduction des orthophosphates est 94-99 %, la réduction de l'ammonium est 80-85 %,la réduction du zinc -3 . Ces niveaux opérationnels optimaux permettent d'avoir une bonne dégradation des margines.Traitement des margines par électrocoagulation 474 est 70-75 %, la réduction du fer est 71-76 %, la masse perdue des électrodes est 0,6-0,7 kg•m -3 et l'énergie consommée est 12-14 kWh•mMots clés : Margine, caractérisation, électrocoagulation, électrodes en aluminium, décoloration, DCO, polyphénols. ABSTRACTOlive 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 , 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][13][14] . Under these optimal operational conditions, acceptable degradation of the OMWW was achieved.