Evaluation of metal contamination and ecological risk in surface sediments of an industrialized catchment: A case study of the Saz-Çayirova catchment, Northwestern Türkiye

Abstract

Investigating the spatio-temporal variations of metal pollution in the sediment of an industrialized watershed, this study aims to identify ecological risks. Utilizing six risk assessment indices-enrichment factor (EF), geo-accumulation index (I-geo), potential ecological risk (RI), contamination factor (CF), ecological risk assessment (ER), and Pollution Load Index (PLI)-the research distinguishes between anthropogenic and geogenic sources. Surface sediment samples are collected from nine locations (comprising seven monitoring sites and two reference sites) across the watershed during both dry and wet seasons. Reference concentrations, tailored to accurately reflect local characteristics, are employed to compute the indices. Results indicate significantly elevated concentrations of Zn, Pb, Cr, Cd, and Ni throughout the basin, exceeding reference values by factors of 15, 20, 5, 10, and 5, respectively. Wet and dry season assessments reveal varying I-geo and EF values across monitoring stations. Cd emerges as the primary ecological risk, predominantly attributed to industrial discharges. Moreover, dry season contamination surpasses that of the wet season. Comparative analysis of the indices reveals PLI's efficacy for spatial assessments, while RI analysis better elucidates temporal variations. In conclusion, this study provides valuable insights for devising strategies to mitigate sediment contamination in industrial watersheds. © 2024 Elsevier B.V., All rights reserved.