Geochemical study of the sediments in main wadis eastern part of Mosul city, Iraq

Abstract

The geochemical changes in the sediments along streams make it possible to predict the processes on the earth's surface, such as weathering, transport, cation exchange, etc. The sediments can also give an environmental indication and the ability to understand the geological situation more clearly. In addition to the sediments being the main sink of heavy elements, they may be a source of pollution with these elements. The study area is situated on the eastern side of Mosul in northern Iraq. Valleys of (Al-Rashediya, Al-Kharrazi, Al-Khosar Al-Danffilli, and Al-Shor) descend from these high areas towards the Tigris River. The sediments of these valleys consist of various components, such as clay minerals, organic matter, iron oxides, carbonates, etc., and heavy elements that are part of or adsorbed on these components. Thirty-six samples were collected from the sediments of these valleys. They were chemically analyzed using the x-ray fluorescence technique to diagnose the chemical composition of these sediments. Several statistical processes were conducted to determine the distribution of heavy elements in the sediments, including the correlation coefficient and factor analysis, which resulted in four principal components representing 80.86% of the total variance. The first, third, and fourth components represent the influence of the weathering and transport factor on the different parent rocks, while the second component represents the human influence factor. The impact of industrial, civil, and agricultural activities on these valleys was studied using a set of pollution indices such as the geoaccumulation index (Igeo) and the enrichment factor (EF). The highest concentrations were in Al-Danffilli valley, especially in the industrial sector, which means that these sites have high levels of pollution compared to other sites that were polluted at lower rates and sometimes not.