Studies on heavy metals in industrial effluent, river and groundwater of Savar industrial area, Bangladesh by Principal Component Analysis

Abstract

ABSTRACT A total number of twenty water samples of which seven groundwater, six river water and seven effluent samples were collected from Savar industrial area in Bangladesh for heavy metals analysis using ICP-MS system. The average concentration of Fe, Mn, Cr, Zn, As, Ni and Pb were 929.97, 101.01, 6.08, 33.36, 9.18, 2.03 and 3.99 mg/L in groundwater; 286.48, 37.65, 0.13, 9.18, 1.39, 1.53 and 1.26 mg/L in river water and 606.64, 72.71, 5.04, 25.05, 1.72, 2.37 and 1.56 mg/L in effluent, respectively. The average concentration of Cr, Mn, Ni, Fe, Pb, Zn and As exceed WHO and DoE, Bangladesh limits in relation to river water and groundwater. The order of average heavy metal content was Fe>Mn>Zn>Cr>Ni>As>Pb in effluent water, Fe>Mn>Zn>Cr>Pb>Ni>As in groundwater and Fe>Mn>Zn>Ni>As>Pb>Cr in river water. Multivariate statistical analyses such as principal component, cluster analysis and correlation matrix shows significant anthropogenic and geogenic intrusions of Fe, Mn, Cr, Zn, As, Ni, and Pb in river and groundwater in the study area. Significant positive correlation between Cr vs Zn, Cr vs As, Mn vs Fe, Mn vs As, and Zn vs Pb indicates their common origin, especially from industrial effluents and municipal wastes that are responsible for the enrichment of these variables as moving together in river water. On the other hand, strong positive correlation between Cr vs As and Ni vs Pb in groundwater reveal the anthropogenic sources of these variables. The high concentration of heavy metals in groundwater and river water may cause serious threat to public health as well as the aquatic environment.