CONTRIBUTION TO THE STUDY OF THE POLLUTION OF NIGER RIVER WATERS: EVALUATION OF PHOSPHORUS, NITROGEN AND DISSOLVED OXYGEN CONCENTRATIONS
SAIDOU HASSIDOU *
Département de Chimie, Faculté des Sciences et Techniques, Université Dan Dicko Dankoulodo de Maradi, B.P. 465 Maradi, Niger,Unité Mixte de Recherche « Science de l’eau, Ressources Minières, Usage et Gestion », Université Dan Dicko Dankoulodo de Maradi, B.P. 465 Maradi, Niger,Laboratoire de Traitement des Eaux Naturelles, Centre de Recherches et de Technologies des Eaux, Technopole de Borj Cedria, Tunisie and Laboratoire de Valorisation des Matériaux Utiles, Centre National de Recherches en Sciences des Matériaux, Technopole de Borj Cedria, Tunisie.
MANZOLA ABDOUSSALAM
Département de Chimie, Faculté des Sciences et Techniques, Université Abdou Moumouni de Niamey, BP 10662 Niamey, Niger.
ABDOULAYE MOUHAMADOU HADI
Département de Chimie, Faculté des Sciences et Techniques, Université Abdou Moumouni de Niamey, BP 10662 Niamey, Niger.
HAMZAOUI AHMED HICHEM
Laboratoire de Valorisation des Matériaux Utiles, Centre National de Recherches en Sciences des Matériaux, Technopole de Borj Cedria, Tunisie.
MNIF ADEL
Laboratoire de Valorisation des Matériaux Utiles, Centre National de Recherches en Sciences des Matériaux, Technopole de Borj Cedria, Tunisie.
*Author to whom correspondence should be addressed.
Abstract
This work is a contribution to the study of the pollution of the Niger River and aims to evaluate the quality of its waters in phosphorus, nitrogen and dissolved oxygen. For that, eight sampling points (Gawèye, Old Bridge, New Bridge, Saga Rice Field, and Niamey National Hospital) were selected. The results obtained show that the phosphorus concentration varies from trace (Gaweye) to 0.143 mg/L (New Bridge 1); The ammonia nitrogen concentration varies from 1.5 mg / L for Gaweye 2 to 2 mg / L for the new bridge 2 and the Saga rice paddy; For dissolved oxygen, it ranges from 3.1 mg / L for the Niamey National Hospital 2 to 8.5 mg / L for the old bridge. The pollution due to phosphorus is moderate at new bridge site and absent at the others sites studied ; that due nitrogen is important at all the eight sites studied, where the pollution due to dissolved oxygen is net at new bridge, absent at old bridge and moderate at the others sites studied.
Keywords: Niger, pollution, nitrogen, phosphorus, oxygen.