Assessment of the Heavy Metal Pollution in the Surface Sediments along Upstream at Wadi Al-Arab, Jordan

Abstract

Twenty stream sediment samples collected from Wadi Al-Arab study area. These samples extracted and analyzed by Atomic Absorption Spectrometer (AAS) to determine their heavy metal for Cu, Zn, Cd, Mn, Fe and Pb concentrations. Calciometry method used to identify the CO₃^-2 content and loss on ignition (L.O.I) at 550 °C used to determine the total organic matter (TOM). The results of the analyses of Wadi Al Arab sediments showed that concentrations of Mn, Cu, Pb, and Fe are safe and these elements are practically unchanged by anthropogenic influences, while the concentration of Zn and Cd exceeded the average shale value. The elevated concentration of Cd and Zn can be due to anthropogenic sources, including fertilizers and pesticides used in agricultural activities, effluent of the treatment plant, and natural weathering of surrounding geological formations. The Pollution Load Index (PLI) analysis indicated that Wadi Al Arab is facing probable environmental pollution especially with dangerous heavy metals (Zn and Cd) which result from increased rate of non-treated wastewater, which discharged to Wadi Al Arab stream. The results of Enrichment Factor (EF) showed high concentrations of Zn and Cd in the study area; these high concentrations in the study area derived from anthropogenic sources including; fertilizers and pesticides used in agricultural activities and the effluent of the close treatment plant. In addition, natural weathering of the surrounding rock formations considered as an additional source of heavy metals to the sediments.

Keywords: Heavy metal, Pollution, Assessment, Sediments, Wadi Al-Arab, Jordan