title: Geochemical speciation, bioavailability and source identification of selected metals in surface sediments of the Southern Caspian Sea.
abstract: Geochemical speciation of As, Cd, Co, Cr, Cu, Ni, Pb, V and Zn were determined in the surface sediments of the southern Caspian Sea. A five-step sequential extraction technique was used to determine the chemical forms of metals. Mean concentrations (ppm) of heavy metals were (mean±S.D.) As: 9.94±1.71, Cd: 0.87±0.23, Co: 14.85±2.80, Cr: 72.29±19.48, Cu: 18.91±4.48, Ni: 32.87±5.25, Pb: 12.48±3.22, V: 86.07±20.71 and Zn: 66.85±10.11. Among the metals, Cu, As, Pb and Zn exhibited relatively higher mobility, while Cd, Co, Cr, Ni and V were found mainly in the residual fractions. Cu and As showed the highest percentages in the exchangeable phase while Co and Cr had the lowest percentages in the phase. The Risk Assessment Code (RAC) values indicated that As, Cu and V had medium risk at some sampling sites. According to pollution load index (PLI), sediments from some sampling sites were polluted.
authors.affiliation: Iranian National Institute for Oceanography and Atmospheric Science (INIOAS), No. 3, Etemadzadeh St., Fatemi Ave., 1411813389 Tehran, Iran. Electronic address: darvish_60@yahoo.com.
authors.forename: Kazem Darvish
authors.initials: KD
authors.lastname: Bastami
authors.affiliation: Department of Chemistry, Faculty of Science, University of Zanjan, Postal Code 45371-38791, Zanjan, Iran.
authors.forename: Mahmoud Reza
authors.initials: MR
authors.lastname: Neyestani
authors.affiliation: Department of Environmental Science, Faculty of Environment and Energy, Science and Research Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Marjan
authors.initials: M
authors.lastname: Esmaeilzadeh
authors.affiliation: Department of Fisheries, Faculty of Animal Science and Fisheries, Sari Agricultural Sciences and Natural Resources University, Km 9 Darya Boulevard, P.O. Box, 578, Sari, Iran.
authors.forename: Sarah
authors.initials: S
authors.lastname: Haghparast
authors.affiliation: Department of Agriculture and Natural Resource, Ardakan University, Ardakan, Iran.
authors.forename: Camelia
authors.initials: C
authors.lastname: Alavi
authors.affiliation: Department of Environmental Science, Faculty of Environment and Energy, Science and Research Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Sanaz
authors.initials: S
authors.lastname: Fathi
authors.affiliation: Department of Marine Science and Technology, Science and Research Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Shahram
authors.initials: S
authors.lastname: Nourbakhsh
authors.affiliation: Novin Shimyar Chemical Laboratory, P.O. Box 14589-3699, Tehran, Iran.
authors.forename: Emam Ali
authors.initials: EA
authors.lastname: Shirzadi
authors.affiliation: Department of Marine Biology, Shahid Chamran University, Ahvaz, Iran.
authors.forename: Reyhane
authors.initials: R
authors.lastname: Parhizgar
mesh_terms: D001682:Biological Availability; D004784:Environmental Monitoring / Q000379:methods*; D019015:Geologic Sediments / Q000737:chemistry*; D019216:Metals, Heavy / Q000032:analysis*; D018570:Risk Assessment; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D019216:Metals, Heavy; D014874:Water Pollutants, Chemical
keywords: Caspian Sea; Heavy metals; Oxide compounds; Speciation; Surface sediment