volume of my thesis in English
- 1. Shiraz University Faculty of Sciences M.Sc. Thesis in Earth Sciences ENVIRONMENTAL GEOCHEMISTRY AND BIOAVAILABILITY OF HEAVY METALS IN COASTAL AND MARINE SEDIMENTS OF GOWATR BAY By Mohammad Javad Nematollahi Supervised by Dr. F. Moore December 2013
- 3. Abstract Environmental geochemistry and bioavailability of heavy metals in coastal and marine sediments of Gowatr bay By Mohammad Javad Nematollahi In this research, distribution and bioavailability of heavy metals in marine and intertidal sediments of Gowatr bay (also gowadar bay) was studied in order to identify natural and anthropogenic pollution. For this purpose, 17 surficial sediment samples, and 5 sediment cores were collected, and analyzed. The results were then compared with local background concentration. Surficial distribution of heavy metals indicate that maximum concentration of Copper and Zinc, Lead, vanadium and chromium, nickel and cobalt is related to Pasabandar harbor, sandy coast, and mudflats of Mangrove jungle, respectively. Calculated correlation coefficients indicate a positive correlation between Iron, clay fraction, organic matter, and potentially toxic metals, especially; Cu, Zn, and Ni. Heavy metals distribution at depth was determined in five sediment cores. Heavy metals are mainly concentrated in cores 3 and 5. Most sediment cores display surficial Pb enrichment, while Ni and Co are concentrated at depth. According to calculated geo-accumulation factors (Igeo), zinc and copper show heavy contamination in Pasabandar harbor. Maximum PLI and RI are also related to Pasabandar harbor. The results of heavy metals fractionation reveal that Cu and Pb, Mn, and Zn, Ni, Co, Cr, V, and Fe are primarily concentrated in reducible, exchangeable, and residual fractions respectively. The dominance of Cu, Pb, Mn, and Zn in non-residual fractions shows high bioavailability and potential risk of these metals in littoral ecosystem. Marine traffic, along with ship yards activity at and close to Pasabandar harbor and mangrove jungle, combined with weathering of ophiolites are apparently responsible for the observed high concentration of heavy metals in Gowatr bay. Keywords: heavy metal, surficial sediment, Gowatr bay, Pasabandar harbor, mangrove jungle, bioavailability