NITRITE CONTENT STUDY IN GROUNDWATER RESOURCES IN NIGER: CASE OF DISCONTINUOUS AQUIFERS OF THE DAMAGARAM-MOUNIO BASEMENT

The Damagaram Mounio bedrock, located in the eastern part of the Zinder region is a densely populated area where access to drinking water is a critical issue. The main objective of this study is to characterize nitrite levels in the groundwater resources of the area. The methodological approach, based on statistical analysis and special analysis, along with comparison of nitrite levels to the WHO standard, yielded several interesting results. Nitrite levels in the Damagaram Mounio basement aquifers range from 0 to 2.84 mg/L, with a mean of 0.42 mg/L and a standard deviation of 0.59. This study showed that 32% of the sampled boreholes have nitrite levels exceeding the permissible limit for drinking water, set at 50 mg/L according to WHO standards; this water is therefore unfit for human consumption. Furthermore, the study highlights a strong correlation between nitrate and nitrite levels. The NO2-NO3 correlation confirms the common origin of these two parameters, primarily linked to human activities and the nitrogen cycle. Analysis of the spatial distribution of nitrite levels in groundwater resources reveals three distinct zones. Furthermore, the results of the PCA suggest that the quality of the studied waters is controlled by two distinct and independent factors: a chemical component of anthropogenic origin and a thermal component of natural origin.