Geochemical distribution, fractionation and contamination assessment of heavy metals in marine sediments of the Asaluyeh port, Persian Gulf Hossein Delshab a , Parvin Farshchi a, ⁎, Behnam Keshavarzi b,c a Department of Environment and Energy, Science and Research Branch, Islamic Azad University, Tehran, Iran b Department of Earth Sciences, College of Sciences, Shiraz University, Shiraz, 71454, Iran c Medical Geology Center, Shiraz University, Iran abstract article info Article history: Received 26 July 2016 Received in revised form 13 November 2016 Accepted 15 November 2016 Available online xxxx In this study, total concentration and speciation of heavy metals in sediments of the Asaluyeh, one of the Iran's largest commercial ports, are investigated. 48 sediment samples were collected and analyzed for trace and major elements. Sediment quality guidelines along with calculated enrichment factors and trace metal profiles indicate that Asaluyeh port is threated by contamination, especially with respect to Hg and Cu. Normalization to Sc indicated high enrichment factors in the sediments following the decreasing order of: Hg N Cu N As N Ni N Zn N Pb ≈ Cr ≈ Mn N Co ≈ V ≈ Fe ≈ Al. Hg displayed the greatest potential ecological risk factor among sampling stations. The results of sequential extraction procedure revealed that in some stations N 50% of Mn, V, Cu and Zn occur in potentially mobile phases and therefore are more readily mobilized in the sed- iments of the study area. © 2016 Elsevier Ltd. All rights reserved. Keywords: Major and trace elements Sediment pollution Fractionation Asaluyeh port Persian Gulf 1. Introduction Metal contamination in aquatic ecosystems has become a consider- able concern due to its toxicity, abundance, and persistence in the envi- ronment, and its subsequent accumulation in aquatic habitats (Lin et al., 2013). Heavy metals discharged into an estuarine environment, either by natural or anthropogenic sources, are distributed between the aqueous phase and sediments through adsorption, hydrolysis, and co- precipitation (Gaur et al., 2005). Sediments are important sinks for var- ious pollutants such as heavy metals and also play a useful role in the as- sessment of metals contamination (Ikem et al., 2003; Moore et al., 2011; Raeisi-Sarasiab et al., 2014). Various studies have demonstrated that sediments from coastal areas are prone to be greatly contaminated by heavy metals (Bellucci et al., 2003; Pekey et al., 2004; Buccolieri et al., 2006; Qiao et al., 2013; Wang et al., 2015); therefore, the evaluation of metal distribution in surface and deep sediments is useful to assess the pollution in the marine environments (Kumar et al., 2013). In addi- tion, metal-contaminated sediments may release metals into the over- lying water column and thus pose a risk to aquatic life and ecosystems (Calmano et al., 1990). Information on the total concentrations of metals alone is not suffi- cient to assess the environmental impact of polluted sediments, as heavy metals are present in different chemical forms in sediments, which determine their mobilization capacity and bioavailability (Usero et al., 1998; Filgueiras et al., 2002; Zemberyova et al., 2006; Rao et al., 2008; Keshavarzi et al., 2014). Metals are generally present in a variety of chemical forms in sediments and exhibit different physico-chemical behaviors in terms of chemical interaction, mobility, bioavailability and potential toxicity (Alvarez et al., 2011). Many differ- ent sequential extraction schemes have been proposed in literature (Schramel et al., 2000; Kaasalainen and Yli-Halla, 2003; Anju and Banerjee, 2010). The most employed procedure is the European Com- munity Bureau of Reference (BCR) three-step sequential extraction technique which harmonizes the various sequential extraction proce- dures (Cuong and Obbard, 2006; Yan et al., 2010; Oyeyiola et al., 2011; Moore et al., 2015). By having one of the highest records of loading and unloading among all Iranian ports, Asaluyeh has become one of the busiest marine areas in the Persian Gulf (Alipour et al., 2014). Accelerated development of urbanization and industrialization and dense mari- time activities in the area and the existence of a huge petrochemical industry in the margins of this port may be responsible for the high- level accumulation of pollutants in the region (Alahverdi and Savabieasfahani, 2012). The main objectives of the present study are: (1) to determine spatial variation of potentially toxic trace ele- ments in the Asaluyeh port sediments; (2) to identify probable pol- lution sources of the sediments; (3) to assess metals bioavailability in the sediments. Marine Pollution Bulletin xxx (2016) xxx–xxx ⁎ Corresponding author. E-mail address: parvinfarshchi@gmail.com (P. Farshchi). MPB-08186; No of Pages 11 http://dx.doi.org/10.1016/j.marpolbul.2016.11.033 0025-326X/© 2016 Elsevier Ltd. All rights reserved. Contents lists available at ScienceDirect Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul Please cite this article as: Delshab, H., et al., Geochemical distribution, fractionation and contamination assessment of heavy metals in marine sediments of the Asaluyeh port, Per..., Marine Pollution Bulletin (2016), http://dx.doi.org/10.1016/j.marpolbul.2016.11.033