Geochemical Characterization of Kor River Water Quality, Fars Province, Southwest Iran

Abstract

A study was conducted on April, 2010 to evaluate the surface water quality from 29 sampling points along the Kor River in Fars province SW Iran. The Kor River plays a key role in supplying water for municipal and industrial users, and for irrigation. In the last few decades rapid industrialization and urbanization along the river course has increased the pollution load of the river water. In this study, 13 physicochemical parameters (pH, EC, NO3, TA, PO4, SO4, As, Cr, Cu, Hg, Mo, Ni, and Zn) are determined and the quality of water is evaluated using various tools, such as piper, sodium absorption ratio (SAR), U.S. salinity laboratory classification (USSL), heavy metal pollution index (HPI) and heavy metal evaluation index (HEI). Results show that the effluents discharged from industrial units and municipal sources has led to increased EC (6500–21510 μs/cm), TDS (4566–12632 mg/l), NO3 (15–1421 mg/l), Cl (1205–7161 mg/l), SO4 (2400–7008 mg/l), Hg (0.1–6.3 ppb), Cr (6–268 ppb), Mo (18.3–78.2 ppb) and Ni (7.4–24.1 ppb) in at least four sampling stations. The Piper plot reveals the dominance of Na+–K+–Cl− type of hydrogeochemical facies. In the USSL plot 34.48% of water samples fall in C2S1, C3S1 and C3S2 zones, which are suitable for irrigation. Also, a reclassification of the HPI and HEI categories using median values show that 3.5% of HPI values and 13.8% of HEI values are classed as high. Sewage inputs from industrial and municipal sources are responsible for the observed high concentration of many physicochemical parameters in the Kor River.