Impact of discharges of wastewater on the physico-chemical and bacteriological quality of the Beni Aza River (Blida, Algeria)

• Published in: Lebanese science journal/Journal scientifique libanais 2014-01, Vol.15 (2), p.39-51
• Main Authors: Bengherbia, Abdelmalek, Hamaidi, Fella, Zahraoui, Rabia, Hamaidi, Mohand Said, Megateli, Smain
• Format: Article
• Language: fre
• Subjects: Freshwater
• ISSN: 1561-3410

The use of waters of the Beni Aza River (Algeria)for irrigation poses a major problem of public health. The sampling strategy developed in this study is based on the analysis of waters of the Beni Aza River. The samples were analyzed systematically to measure all the physicochemical indicators of pollution: COD, BOD sub(5), SS, nitrate and nitrite, ammonium, phosphate and organic matter. The results showed that whatever the day of sampling, the stream is exposed to heavy pollution of mainly organic origin. This pollution levels expressed by COD (417 mgO sub(2)/l), BOD sub(5) (219 mgO sub(2)/l) and MES (663 mg/l), was very high, exceeding the WHO and Algeria standards. Correlations between pollution parameters were conducted to give a response element on the main causes of pollution. The bacteriological results obtained showed the presence of significant levels of total coliforms (188t10 super(7) UFC/100ml), fecal coliforms (46t10 super(7) UFC/100ml) and fecal streptococci (28t10 super(7) UFC/100ml). Pathogens such as Salmonella and Vibrio were not detected.Original Abstract: L'utilisation des eaux de l'oued Beni Aza pour l'irrigation pose un probleme majeur de sante publique. Les echantillons preleves des eaux de l'oued Beni Aza ont ete systematiquement analyses en vue de mesurer tous les parametres physico-chimiques indicateurs de pollution: DCO (demande chimique en oxygene), DBO sub(5), (demande biochimique en oxygene sur 5 jours), MES (matieres en suspension), nitrates et nitrites, ammonium, phosphates et matieres organiques. Les resultats obtenus montrent que le cours d'eau est expose a une forte pollution principalement d'origine organique. Cette pollution est exprimee par une DCO (417 mgO sub(2)/l), une DBO5 (219 mgO sub(2)/l) et des MES (663 mg/l) tres elevees depassant largement les normes algeriennes et celles de l'OMS. Des correlations entre les parametres de pollution ont ete effectuees afin de donner des elements de reponse aux causes principales de la pollution. Ces analyses ont fait egalement l'objet d'une recherche bacteriologique. Les resultats bacteriologiques obtenus montrent la presence d'un taux eleve en CT (coliformes totaux) (188t10 super(7) UFC/100ml), en CF (coliformes fecaux) (46t10 super(7) UFC/100ml) et en SF (streptocoques fecaux) (28t10 super(7) UFC/100ml). L'absence de germes pathogenes comme les salmonelles et les vibrions a ete signalee.