Fractionation of mercury in sediments during draining of Augusta (Italy) coastal area by modified Tessier method

Abstract

A modified Tessier method was applied to sediments dredged from Augusta (Italy) coastal area with the purpose of establishing the amount and the forms in which mercury is present in the different sediment fractions. The mercury fractionation was made by measuring the concentration of the metal ion on the solutions and directly on the sediment fractions obtained by sequential extraction. The measurements on the solutions as well as that on the solid fractions were carried out by using a Direct Mercury Analyser, DMA 80. This new instrument does not require sample preparation, and gives results comparable to those obtained with CV-AAS and ICP-MS and few minutes are necessary for each analysis. The quality of the experimental data together with the applicability of the technique to real samples was checked by analyzing certified reference materials (CRM) and some sediment samples collected from the coastal site during the research. The results of fractionation analysis were used as an assessment tool to establish the best remediation technique for removal of mercury from this polluted area.