Assessment of Accumulation, Spatial Distribution and Sources of Potentially Toxic Elements (PTEs) in Sediments of a Saline Lake

Abstract

Potentially Toxic Elements (PTEs) are hazardous for human and ecosystem health due to their non-biodegradable nature. In this study we investigated the concentrations of PTEs, including As, Co, Cr, Cu, Mn, Mo, Ni, Pb and V in sediments of Lake Tuz around the salt pans for possible contamination. Lake Tuz is a shallow saline lake where halite (table salt) production is carried out in the salt pans and has significant geo and eco-tourism potential due to its unique ecosystem and natural beauty. The extent of pollution level and ecological risk were evaluated by geochemical indices and guideline values. According to the Geoaccumulation Index (Igeo), Enrichment Factor (EF) and Contamination Factor (Cf) indices Cr, Mo, As and occasionally Ni accumulated in moderate to strong levels. Intensity maps of Pollution Load Index (PLI) and Modified Degree of Contamination (mCdeg) indicated pollution hotspots in the neck region and in the eastern shore of the lake respectively. The Potential Ecological Risk Index (PERI) values indicated low and moderate levels of ecological risk. Statistical analyses including Pearson Correlation Coefficient (PCC), Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA) suggested that Co, Cr, Cu, Mn, Mo, Ni and V are of geogenic origin and As and Pb are of anthropogenic origin. Provenance analysis suggested that host rocks for geogenic PTEs were granodiorites and ophiolites situated in the catchment area of the lake. Anthropogenic PTEs were most likely related to agrochemicals used in surrounding farmlands.