Physicochemical Characterization and Determination of Scaling and Corrosion Sources in the Groundwater of Tillabery, Niger

Abstract

In Niger, in the Tillabéry region, despite surface water, groundwater constitutes the major source of drinking water supply for various populations. This study aims to assess the quality of groundwater in some villages in the Tillabéry region to understand the source of scaling and corrosion of some boreholes. Thirty-one samples were taken and then analyzed using in situ and conventional methods according to French AFNOR standards based on thirteen physicochemical parameters. The results of these analyses were processed with the Diagram and XLSTAT software. The physicochemical analyses of the waters show that their quality is mainly linked to the geogenic source of the soil and to human activities. Piper diagram analysis results show that these waters are all sulfated, with values ranging from 270 to 1528 mg/L, sodic from 5.3 to 1189 mg/L and potassic from 2.8 to 98, 7 mg/L, with the exception of Guemé water, which is bicarbonated at 1342 mg/L, Boukanda2 water, which is chloride-rich at 2083 mg/L, and Fanaka Koira1 and Lallé Tondi water, which are calcium-rich at 236 mg/L and 145.01 mg/L respectively. The principal component analysis with XLSTAT shows that the Na+, Cl-, K+ ions  govern the mineralization of the water. The Mg2+, Ca2+, Fe 2+, SO42- , F- ions have a geogenic source while the NO2- , NO3- ions have an anthropogenic source. The results of the corrosion indices calculated from the modified Larson index formula showed that 97% of the analyzed waters have a tendency to corrosion. The highest value (191.68) belongs to the village of Gabdey Bangou. Several equations are described to justify the various scaling and corrosion mechanisms that occur, leading to a proposal for simple, less costly water treatment methods to limit these problems.