Structural and elemental analysis of sediments from Demirköprü Dam Lake by SEM/EDS (scanning electron microscopy/energy dispersive spectroscopy) and ecological risk evaluation

Abstract

Abstract Human activities, industrialization and natural processes cause to pollution of aquatic ecosystems. To evaluation the level of sediment pollution and ecological risk in Demirköprü Dam Lake, the concentrations of eighteen major, trace and rare elements (O, Si, Al, Fe, K, Ca, Na, As, Nb, Ti, Cd, Cu, Sc, Pb, C, Zn, Br, and Cr) were seasonally analyzed using SEM/EDS (scanning electron microscopy/energy dispersive spectroscopy). Our results indicated that chemical elements in sediment accumulated in the following orders: O > Si > C > Al > Fe > Br > K > Ca > As > Na > Ti > Pb > Nb > Cd > Zn > Cu > Cr > Sc. Seasonal fluctuations strongly impacted the levels of some elements (O, Al, Fe, Ca, Na, Nb, Cd, Pb, C and Br) in sediment (P < 0.05). Sc as a strategic rare earth element was firstly reported in the current study in Demirköprü Dam Lake. Br levels in sediment samples only detected in winter while Nb levels only detected in winter and spring. Pollution indices (pollution load index (PLI), geoaccumulation index (IGEO) and enrichment factor (EF)) are below the limits in all seasons, except Ca. As an effective approach, freshwater ecosystems should be monitored for preventing pollution through elemental analysis of sediments.