Assessment of Arsenic Presence in Some Water Points in Different Areas of Benin

Abstract

Arsenic is a metalloid that appears in water naturally or after human activities. Above 10 μg/L recommended by WHO (2004), this element is toxic for human being. In Benin, the areas where the contents are considered to be higher have been the subject of this research. These include the gold area of Kouatena, the volcanic and sediment areas of Daho-Mahou and Pako and the iron area of Madecali. The common elements in water and the elements that have affinity with arsenic have been mixed and speciation of arsenic has also been done. At the end of analysis the arsenic contents in the volcano-sedimentary zones are below the guide value but with maxima very close to this one (8.20 μg/L for Daho Mahou and 9.30 μg/L for Pako). Elevated concentrations were recorded in the gold (with a maximum of 16.02 μg / L) and ferruginous (with a maximum of 11.03 μg / L) zones. After the speciation, the amount of As (III) is higher than As (V) in all samples of water. The speciation is function to pH and redox potential.