Trace metals in Adriatic coastal sediments: Distribution and speciation pattern

Abstract

Abstract In the framework of the Italian National Project for the safeguard of Adriatic Sea (PRISMA 2), distribution of trace metals in surface coastal sediments of two areas influenced by river Po freshwaters (Ancona and Chioggia) was studied. A sequential extraction technique was used to determine the chemical association of heavy metals (Pb, Cu, Cd, Fe, Hg, Sn, Co and Zn) with major sedimentary phases (exchangeable ions and carbonates, Mn and Fe oxides, sulphides and organic matter and residual minerals). The relationship between the metals content and the grain‐size composition of the sediments was studied: all the elements resulted associated principally with the fine fraction. The considered sediments are not particularly polluted and speciation revealed that the major part of the heavy metals present are not easily mobilizable and bioavailable. Key words: Selective extractionmetal speciationsolid speciationAdriatic Sea Notes Corresponding author. Fax: +39 010 3536190. E‐mail: ianni@chimica.unige.it