Microbiological Survey And Wastewater Reuse Possibility For Crop Production. A Case Of El Kouwaer Plant During Dysfunction Period, Algeria

Résumé: Description of the subject: The Study of the proliferation of filamentous bacteria and the identification of pathogenic microorganisms, particularly at the level of treated water, influence the wastewater valorization in the field of agricultural irrigation. Objective: The objective of this study is to evaluate the microbiological quality of El Kouawer wastewater treatment plant located in Mascara department during dysfunction period in order to determine the possibility of reutilization of effluent wastewater in agriculture for crop irrigation. Methods: 51 samples were taken during the plant dysfunction over a period of four months. Microscopic examinations were carried to establish the morphological aspects of filamentous microorganisms. Pathogenic bacteria and fungal floras were isolated, identified and numerated in influent and effluent wastewater samples. Results: Microscopic examinations show a great diversity of filamentous bacteria in the aeration tanks: Microthrix parvicella, Nostocoïda limicola groups (I, II and III), Bogiotae sp and Sphaertilus natans. At the level of effluent wastewater twenty-two (21) different pathogenic species were isolated: Enterobacteriaceae, Staphylocoquaceae, Pseudomonaceae, Aeromonas hydrophilae/caviae, Vibrio parahaemolyticus, Bacillus cereus and Streptococcus sp. Also, four (04) yeasts: Candida albicans, Candida glabrata, Trichosporon sp and Cryptococcus neofarmans, and four (05) filamentous fungal species: Aspergillus niger, Aspergillus flavus, Aspergilus ochraceus, Aspergillus fumigatus and Penicillium sp. The Removal Allowance (RA) of the different flora estimated for each month was low, except for total flora which was of 0.85 value. Conclusion: During dysfunction period, El Kouwaer plant is characterized by an excessive proliferation of filamentous bacteria responsible for bulking phenomenon, significant numbers of pathogenic bacteria and fungal floras, and low Removal Allowance (RA) values. According to the standards decreed by the Algerian official journal, the purified water can be classified in the category B. This water can be reused for the irrigation of crops such as including cereals, fodder and fruit trees.

Publié dans la revue: AGROBIOLOGIA