Multivariable cokriging prediction and source analysis of potentially toxic elements (Cr, Cu, Cd, Pb, and Zn) in surface sediments from Dongting Lake, China

Abstract

Sediment acts as both important sink and source for contaminants in aquatic systems. In the present study, the multivariable cokriging method and multiple statistical techniques, including group analysis (GA), factor analysis of mixed data (FAMD), correlation matrices (CMs), and enrichment factor (EF) were used to identify spatial distribution and sources of potentially toxic elements (PTEs) Cr, Cu, Cd, Pb, and Zn in surficial sediments of Dongting Lake in China. The results showed significant spatial heterogeneity in these PTEs in Dongting Lake. The average concentrations of Cr, Cu, Cd, Pb, and Zn were 131.5 ± 45.4, 49.7 ± 17.4, 2.2 ± 1.8, 59.2 ± 18.6, and 152.9 ± 48.0 mg/kg, respectively. The potential ecological risks posed by the trace elements (Cr, Cu, Cd, Pb, and Zn) were evaluated based on the multivariable cokriging predictions, and the results indicated that the ecological risks were high in Southern and Western Dongting Lakes. Multiple analyses showed that Cr, Cu and Zn primarily originated from industrial and domestic sewage wastewater, while Cd and Pb were primarily from agricultural and industrial sources.