Trace element mobility, regional significance and global implication of Gomati river basin, northern India

Abstract

We studied trace element mobility in the Gomati River (an alluvial tributary of the Ganga River in northern India) Basin by analyzing thirty-six time series water samples for their dissolved concentration of trace elements. Sodium-normalised elemental mobility indices vary over a wide range of the six orders of magnitude from 102 (Cd) to 10–4 (Zr). The highly mobile elements are B, As, Se, Sr, Mo and Cd. The moderately mobile elements are Al, P, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb and Pb. Titanium, Fe and Al, commonly assumed to be immobile at global level, are identified as moderately mobile elements. High trace element mobility in the Gomati River Basin had the geogenic factor associated with the chemical weathering of biotite mica mineral. For the river water quality assessment, the concentration of B, Cr, Cu, Zn, As and Pb lies below the desirable limits; while the concentration of Al, Fe and Se are above the WHO permissible limits of drinking water. At global scale, the Gomati River Basin contributes dissolved flux in significant proportions, namely Al (5.8%), Ti (4.4%), Fe (1.1%), Ni (1.2%), Se (21.5%) and Pb (1.7%) of total riverine flux. The proposed system model may provide means of qualify and quantify the environmental effects of trace elements mobility.