Search results for " geochimica"

Zr, Hf and REE distribution in river water under different ionic strength conditions

2018

International audience; The Platani River flowing in south-central Sicily, interacting with evaporite rocks, generates a wide range of ionic strength in the water catchment from 0.1 to 5.0 mol kg−1. We sampled 38 river sites and analysed the composition for the dissolved fraction filtered through 0.45 μm, the truly dissolved fraction obtained through ultrafiltration (10 kDa) and the relative included colloidal fraction.This study was focused on the recognition of Zr, Hf and REE behaviour under changing ionic strength conditions, since this is one of parameters responsible for colloid stability in natural waters. In turn, this phenomenon leads to REE release from the colloidal fraction and t…

Metal distribution in road dust samples collected in an urban area close to a petrochemical plant at Gela, Sicily

2006

Eight samples of road dust were collected from three different localities (industrial, urban, peripheral) of the town of Gela (Italy) to characterize their chemical composition and to assess (a) the influence of the petrochemical plant and the urban traffic on the trace element content in different grain-size fractions of street dust and (b) the solid-phase speciation of the analysed metal using sequential extraction. The samples were sieved into six particle size ranges: 500–250, 250–125, 125–63, 63–40, 40–20 and <20 μm and then analysed for 15 trace elements by ICP-MS. Sequential extraction of metals was performed on each subsample. A principal component analysis was also carried out to d…

Lead isotopic fingerprint in human scalp hair: The case study of Iglesias mining district (Sardinia, Italy)

2017

The Sulcis-Iglesiente district (SW Sardinia, Italy) has been, until recently, one of the most important Italian polymetallic mining areas for the extraction of lead. Epidemiological studies conducted over several decades have indicated this site at high risk of environmental crisis with possible adverse effects on the public health. In the present paper we discuss Pb isotope signatures in human scalp hair and road dust collected from the Sulcis-Iglesiente area in order to trace the exposure of populations to potential Pb sources. A total of 23 determinations (20 on hair samples and 3 on road dust samples) of lead isotope ratios (206Pb/207Pb and 208Pb/206Pb) were carried out. The obtained re…

Monitoring SO2 degassing on Stromboli using a permanent UV Camera network

2020

PETROLOGICAL AND EXPERIMENTAL CONSTRAINTS OF THE PRE-ERUPTIVE CONDITIONS OF LA SOMMATA BASALT AND BROWN TUFFS TEPHRA (AEOLIAN ISLANDS)

2011

The principal focus of this thesis was the reconstruction of pre-eruptive conditions of two key eruptions at Vulcano island, the Brown Tuffs and the La Sommata, by combining the melt inclusion approach with phase equilibria derived by crystallization experiments. Brown Tuffs (the most energetic and widely distributed eruption of the Archipelago) were produced by several eruptions that occurred in a large age interval, 78-7.7 ka B.P. At Vulcano BT deposits crop out as proximal facies. La Sommata centre (age ca. 50 ka B.P.), is instead a basaltic scoria cone fed by one of the most primitive magmas of Aeolian Arc with ankaramitic affinity. Pyroxene-hosted melt inclusions on Lower and Intermedi…

SEA-LEVEL AND CLIMATIC CHANGES DURING THELAST 41,000 YEARS IN THE OUTER SHELF OF THE SOUTHERN TYRRHENIAN SEA: EVIDENCE FROM FORAMINIFERA AND SEISMOST…

2012

Simultaneous determinations of zirconium, hafnium, yttrium and lanthanides in seawater according to a co-precipitation technique onto iron-hydroxide

2013

Very low concentrations (pg mL 1 or sub-pg mL 1 level) along with the high salinity are the main problems in determining trace metal contents in seawater. This problem is mainly considered for investigations of naturally occurring YLOID (Y and Lanthanides) and Zr and Hf in order to provide precise and accurate results. The inductively coupled plasma mass spectrometry (ICP-MS), both in high and low resolution, offers many advantages including simultaneous analyses of all elements and their quantitative determination with detection limits of the order of pg mL 1. However in the analysis of YLOID in seawater, a better determination needs an efficient combination of ICP-MS measurement with a pr…

Determination of Water-Soluble Trace Elements in the PM10 and PM2.5 of Palermo Town (Italy)

2022

This study contributes to the current knowledge on the solubility of trace elements in the atmospheric particulate matter of the urban area of Palermo. Daily sample filters of PM10 and PM2.5 were collected in monitoring stations within and outside the urban area, characterized by variable traffic density. The bulk of compositions in PM10 and PM2.5 were determined by ICP-MS. The water-soluble trace elements (WSTE) and major ion components of particulate matter were determined by ICP-MS and ion chromatography, respectively. A significant difference in the metals content was observed between the samples taken in urban areas and those from suburban areas. The calculated enrichment factor highli…

Highly contaminated areas as sources of pollution for adjoining ecosystems: The case of Augusta Bay (Central Mediterranean).

2014

An assessment of trace element and polycyclic aromatic hydrocarbon (PAH) contamination based on surface sediments collected in summer 2012 was carried out in Priolo Bay adjoining one of the most polluted areas of the Mediterranean Sea, the industrial Augusta harbour (Italy, Central Mediterranean). Inorganic and organic contaminants were generally not remarkable. Occasional elevated concentrations of Hg, Cd, Ni and PAHs exceeding sediment quality guidelines were detected in the northern sector of Priolo Bay, close to Augusta harbour, possibly as a result of water drainage of industrialised and urbanised areas and/or potential direct export of contaminated material from Augusta harbour, whose…

Analysis and assessment of trace element contamination in offshore sediments of the Augusta Bay (SE Sicily): A multivariate statistical approach base…

2014

Abstract An application of multivariate statistical methods is provided to identify anthropogenic contaminants and lithogenic elements in offshore sediments collected near the heavily industrialized Augusta Bay, Sicily. An exploratory statistical technique, based on canonical correlation analysis (CCA) and mixture density estimation approach, is used for distinguishing between natural and anthropogenic contributions of trace elements in the investigated sediments. Following the intensive industrialization of Augusta area, marine sediments reveal the severe impact of local anthropogenic activities for many elements (e.g. As, Cd, Hg, Pb, and Sb), which are considered very dangerous for the en…