Evaluation of the mineral nitrogen pollution of the surface waters of the ramsar wetland of lake fetzara (North-east algeria)

By its size and specificity, the Ramsar wetland of Lake Fetzara is representative of the rare type of natural wetland in the Mediterranean region. The agropastoral activity practiced in its peripheral zone and the wastewater of the surrounding urban agglomerations constitute potential sources of pollution of the lake waters by nutritive elements. This study was conducted with the objective of assessing the pollution of surface waters of the Fetzara Lake wetland by mineral nitrogen. By a spatio-temporal physicochemical approach, the analytical results obtained show that the wetland waters are not polluted by the nitrate ion, whereas the majority of these waters are rich in nitrite ions. The agricultural activity that characterizes this area would be the direct or indirect source of this pollution. With regard to ammonium ion contamination, all the stations studied have net pollution with maximum values (up to 20.7 mg∙L-1) in stations receiving urban wastewater. The mineral nitrogen concentrations become considerably high during the year 2016 and vary spatially depending on the distance from the source of pollution and with respect to the wet and dry seasons. © Revue des Sciences de l’Eau, 2020.