Distribution of trace metals in marine sediments of the Bay of Palma de Mallorca (Mallorca Island, Spain)

Abstract

Metals were determined in surface bottom marine sediments of the Bay of Palma de Mallorca (Spain) by microwave-assisted acid-oxidant digestion and inductively coupled plasma-optical emission spectrometry in order to assess the level and distribution of potentially metallic pollutants. Average concentrations found were 1.2 ± 0.3 Al and 1.9 ± 0.9 Fe (in milligrams per gram), and 8 ± 2 Cr, 2 ± 1 Cu, 60 ± 10 Mn, 4 ± 1 Ni, 6 ± 4 Pb, 50 ± 7 Sn and 10 ± 3 Zn (in micrograms per gram). Enrichment factors using normalized values to Al were also calculated which indicated that sediments were Sn and Pb enriched. Sediments were fractionated by grain size: <63, 63-250, 250-500 and >500 (in micrometres), and the metals' affinity towards the different fractions was studied. The metals' affinity to the finer fraction was evidenced, excluding Sn and Mn that showed practically no affinity for fine grains. Latent variables were extracted from the data using principal components analysis. It allowed samples to be grouped in two clusters, and most of the metals (Al, Cr, Cu, Fe, Ni, Pb and Zn) showed a similar distribution pattern. Sn and Mn showed a distinct pattern.

Determination of heavy metals in marine sediments using MAME-GFAAS

“…[7][8][9] Due to the hydrophobic behaviour of these metals, their concentration in seawater is very low, and they instead tend to accumulate in marine sediments. [8][9][10][11][12] This trend is due to adsorption, co-precipitation and metal complexation in the surface layers of ne sediment particles. Thus, four types of metal fractions can be distinguished: (a) the exchangeable fraction, which is located in the ion exchange sites and it is freely available to take part in chemical reactions, (b) the reducible fraction, consisting of complex oxides and hydroxides, which is soluble under reducing conditions, (c) the oxidizable fraction, which is formed with the organic matter and sulphides, and it is available under oxidizing conditions, and (d) the residual fraction, which is introduced into the environment in the crystalline form by geological processes and it is generally not available.…”

“…8 Marine sediments act as metal reservoirs and, for that reason, the analysis of metals in marine sediments allows us to detect pollution in the marine environment and provides information about the ecosystem health. [8][9][10][11] Traditionally, methods for extraction and analysis of metals in marine sediments use highly toxic and corrosive extractants; strong acids are oen used. 14 These extractants have to be applied for long periods (12 hours) and at high temperatures (180 C), a process known as "acid digestion".…”

“…Heavy metals considered in this study (Ni, Cr, Cu, Pb and Cd) are categorized as priority pollutants by the U.S. Environmental Protection Agency (6). They have proved to be important pollutants in the marine environment, with high toxicity, long persistence and rapid accumulation at living organisms (7-9).Due to the hydrophobic behaviour of these metals, their concentration in seawater is very low, and they instead tend to accumulate in marine sediments (8)(9)(10)(11)(12). This trend is due to adsorption, co-precipitation and metal complexation in the surface layers of fine sediment particles.…”

“…Due to the hydrophobic behaviour of these metals, their concentration in seawater is very low, and they instead tend to accumulate in marine sediments (8)(9)(10)(11)(12). This trend is due to adsorption, co-precipitation and metal complexation in the surface layers of fine sediment particles.…”

Analysis of Ni, Cr, Cu, Pb and Cd in marine bioindicators using mixed-micelles with microwave assisted micellar extraction and GF-AAS

“…The methodologies used in the characterization of environmental quality are oen applied to solid matrices due to their ability to concentrate hydrophobic pollutants. [1][2][3][4] These contaminants, such as hydrophobic organic contaminants (PBDEs, Dechloran Plus (DP), benzotriazoles (BTRs), benzothiazoles (BTs) and benzenesulfonamides (BSAs)) and heavy metals, are found in the environment at very low concentrations. [5][6][7] Therefore, it is common to nd studies using sediments or marine organisms as matrices, enabling us to correlate them with the degree of environmental pollution.…”