Assessment of geological source and geochemical dispersion of heavy metals in the sediments of brine springs in Khouzestan Province

The present work deals with the concentration and dispersion of heavy metals (i.e., Pb, Cd, Zn, Ni, Co, Cr, and As) in the sediment samples of 13 brine springs (i.e., Pirmusa, dual springs of Gare-Bardi, triple springs of Ghale-Madreseh, Batvand, Kuhzar, Aghili, Haftanan, Ghasem-Abad, Ispareh, and Dobalutan) in the Khouzestan Province. Geologically, these springs are located in the Zagros Fold and Thrust Belt (ZFTB) and emerged in the Gachsaran Formation. Besides characterizing the geological features, the dispersion of heavy metals were interpreted using geo-environmental parameters including contamination factor (Cf), enrichment factor (Ef), potential ecological risk (Eri), and modified ecological risk index (MRI) with statistical methods including Principal Components Analysis (PCA). Most of the studied samples represent Cf Cf <3, indicating low to moderate (for Cd, Pb, and As) degrees of contamination. Also, the majority of studied samples represent Ef >1 and Ef ≤ 3.53 which suggest minimum to moderate degrees of enrichment. Except for Cd contents in the Ghale-Madreseh 3 and Gare-Bardi 2 samples, the rest of other samples totally exhibit low levels of Eri. Also, the values of modified ecological risk index are categorized in low rick field. Principal component analysis (PCA) implies that Co contents were sourced from the Gachsaran lithology, while As, Ni, Cr, Pb, and Cd are most probably related to the contribution of oil-field related brines.