Heavy metals and polycyclic aromatic hydrocarbons in surface sediments of Karoon River, Khuzestan Province, Iran

Abstract

Karoon is the longest river in Iran and provides water for industries located along its banks, such as metal, petrochemical, and oil industries. It is also the source of drinking water for cities such as Ahwas, Abadan, and Khorramshahr. In this study, 34 and 18 surface sediment samples were collected and analyzed for heavy metals (Al, As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) and polycyclic aromatic hydrocarbons (PAHs). The measured concentrations of heavy metals were compared with US EPA sediment quality guidelines, and the results showed that Cu concentration was above the threshold effect level (TEL) in 65.67% of the samples and Hg concentration was above the effect range median (ERM) in some samples. The results revealed that Hg was severely enriched (5 < enrichment factor < 20) and classified in very high ecological risk index category. It is the major metallic contaminant in the study area. The total PAH concentrations ranged from 11.54-117,730 μg/kg, with the mean value of 7034.55 μg/kg dominated by lower molecular weight (LMW) PAHs. The total potentially carcinogenic PAHs (∑cPAHs) in sediment samples ranged from 2.09 to 31,930 μg/kg, indicating high carcinogenic potential of sediments in the study area. The total toxic equivalent (TEQ) values ranged from 1.06 to 7228.7 μg/kg. Maximum TEQ occurred in Abadan oil refinery station followed by Khorramshahr soap factory and Abadan petrochemical complex. Principal component analysis and cluster analysis also revealed the relationships between the studied parameters and identified their probable sources.

Aliphatic and polycyclic aromatic hydrocarbons risk assessment in coastal water and sediments of Khark Island, SW Iran

“…The adverse effects on organisms would rarely be observed when concentrations fall below the ERL, TEL and TEC values, in contrast the PEL, ERM and PEC values represent a concentration above which adverse effects are more probable (Table 2) (Keshavarzi et al, 2015;Manuel Nicolaus et al, 2015;OSPAR, 2009;USEPA, 2002;Weinstein et al, 2010). Furthermore, in order to assess the potential ecological risk of PAHs on aquatic biota, Risk Quotients (RQ) are commonly used as follow:…”

Contamination Evaluation and Source Identification of Heavy Metals in the Sediments from the Lishui River Watershed, Southern China

“…Following the frequency of natural and anthropogenic activities and the discharge of heavy metals into rivers, contamination is ubiquitous in the aquatic environment [5]. The natural sources of heavy metals mainly include geological weathering, soil erosion, and airborne dust [6]. Anthropogenic activities are the major cause of heavy metal pollution in the aquatic environment, such as industrial discharges, vehicular exhaust, mining operations, agricultural cultivation, and atmospheric precipitation [6,7].…”

Impacts of Sugar mill's Effluent on soil and Plant's Seed Germination, Punjab, Pakistan

“…The morphological parameters like germination percentage, seedling length and fresh % dry weights of the plants were observed. Root and shoot length were also absorbed [43,[48][49][50].…”