Physico-Chemical Characterization of Surface Waters, Traditional Wells and Cisterns Waters Consumed in the Town Halls of Agbangnizoun and Za-kpota In South Bénin

Abstract

The majority of households in the town halls of Agbangnizoun and Za-Kpota do not have access to drinking water due to the non-existence of drinking water supply. Consequently, the communities of these two town halls use surface waters, traditional wells and cisterns to satisfy their daily needs without any prior treatment. This work was undertaken to assess the physico-chemical quality of these waters. Thus, over two successive years, twelve (12) rivers, eighteen (18) wells, twenty (20) cisterns and two (02) boreholes (witness samples) were sampled in the Districts of the two town halls. The physical parameters such as the pH, the temperature, the turbidity, the rate of dissolved solids (TDS) and the conductivity were measured in situ with a mobile multi-parameter device of the brand HANNA HI 9829 while the colour, the suspended matters (SM), the ammonium, nitrate, nitrite, phosphate and sulphate ions are measured in the laboratory by colourimetric method. The data collected were recorded in Excel and then treated with software R. The Student-Newman Keuls test with the significance level of 5% shows that surface waters are more polluted whereas well waters are highly mineralized. The waters consumed by the populations of Agbangnizoun and Za-kpota town halls do not respect drinking water standards.