WATER QUALITY ASSESSMENT OF PERMA GOLD BASIN IN THE NORTHWEST OF BENIN [THROUGH PRINCIPAL COMPONENT ANALYSIS (PCA)]

Abstract

The following research/study evaluates the physico-chemical quality of water i n t h e gold basin of Perma Region where intense gold mining activities have been carried out for several decades in addition to agriculture. It is carried out on 24 physico-chemical parameters of three water sources (boreholes, traditional wells and River in Perma) taken in March-April 2020 and submitted to physicochemical analyses and then submitted to the Principal Component Analysis (PCA). The physico-chemical parameters of water indicate their acidity with an average pH of 6.09. The relevant water are weakly mineralized with a strong colour (270.66) and turbidity (112.33), exceeding Benin guidelines. The presence of iron (1.5) and ammoniacal nitrogen (1.213) in the river is higher than Benin and WHO standards. Cyanides (CN--), mercury (Hg2+), and lead (Pb2+) are present in wells used as drinking water with concentrations of 0.059; 0.384; 0.005 respectively, which are above WHO standards. These heavy metals used by gold miners pollute water sources. The PCA carried out on the 20 physico-chemical parameters shows that the two factors account for 100% of the total variance with 69.97 % for the F1 factor and 30.03% for the F2 factor. Parameters such as pH, colour, turbidity, chlorides (Cl-), nitrites (NO2-), sulphates (SO4 2-), ammoniacal nitrogen (NH4 +), total iron (Fe /Fe2+/Fe3+) and fluoride (F) are positively correlated with F1 and then negatively correlated with alkalinity and bicarbonates (HCO). As for the F2 factor, it is positively correlated with temperature, color and Calcium (Ca2+), and negatively correlated with Nitrates (NO3-) and Phosphates ((PO4 3-)