Assessment of heavy metals pollution in surface and groundwater systems in Oued Righ region (Algeria) using pollution indices and multivariate statistical techniques

Abstract

Surface and groundwater samples of the Oued Righ region (south-eastern Algeria) were analysed for Cd, Cr, Cu, Mn, Ni, Pb and Zn by atomic  absorption spectrophotometric method. An integrated approach of pollution evaluation indices and multivariate statistical methods (one-way ANOVA, principal component analysis [PCA] and cluster analysis [CA]) was employed to evaluate the intensity and sources of heavy metals of surface and groundwater systems in Oued Righ region, south-eastern Algeria. The heavy metal pollution index (HPI) of groundwater was below the critical index limit of 100, pointing to the fact that the groundwater is not polluted with respect to heavy metals. The heavy metal evaluation index (HEI) values ranged from 2.33 to 7.07, with a mean value of 4.03 for surface water, and from 0.95 to 2.77, with a mean value of 1.42 for the groundwater samples. The pollution indices show similar trends at the various sampling points. In addition, significant correlations are observed between them in surface water and groundwater samples. Furthermore, multivariate statistical analysis results demonstrated that natural and anthropogenic activities were major sources of water contamination in Oued Righ region.

Keywords: CA, cluster analysis, ground water, PCA, principal component analysis, surface water, water pollution