Spatial Variation of Metals in the Batang Arau River, West Sumatera, Indonesia

Abstract

This paper aims to assess metallic pollution in the Batang Arau River, an important source of freshwater supply for local communities in West Sumatera, Indonesia, by applying multivariate statistical techniques. Sampling was conducted at eight stations along the river from March to May 2014. The results indicate that all the metals studied have similar spatial distribution patterns, with an increasing trend in concentration from upstream to downstream. Total concentration of six metals studied upstream, as background concentration, was 1.050 mg/L, and increased to 2.249 mg/L downstream. Spatial distribution of metals did not show significant variability ( p < 0.05) for Cd, Cr, Fe, and Pb, but Co and Mn did. The results of principal component analysis/factor analysis (PCA/FA) and correlation analysis suggest that Cd, Co, and Fe are originated from natural and anthropogenic sources; Cr and Pb are derived from natural sources; and Mn is controlled by anthropogenic sources.