Search results for "aerosol physics"
showing 10 items of 83 documents
ASSESSING MERCURY POLLUTION USING BLACK STORK EGGSHELLS
2021
Female birds whose bodies contain environmental contaminants produce eggs with shells that are likewise contaminated, making bird eggshells appropriate indicators for monitoring environmental toxins. Common contaminants include organic mercury compounds, especially methylmercury, which are known to bioaccumulate and biomagnify in the food chain. Black storks (Ciconia nigra) predominantly consume fish and are thus at risk for high mercury intake. In this study, we used eggshells of black storks as a proxy to reconstruct the concentration levels and distribution of mercury, a well-known toxic element, in various parts of Latvia. Preliminary analyses have shown that deposition levels of mercur…
Modeling of 137Cs migration in soils using an 80-year soil archive: role of fertilizers and agricultural amendments
2008
An 80-year soil archive, the 42-plot experimental design at the INRA in Versailles (France), is used here to study long-term contamination by 137Cs atmospheric deposition and the fate of this radioisotope when associated with various agricultural practices: fallow land, KCl, NH4(NO3), superphosphate fertilizers, horse manure and lime amendments. The pertinence of a simple box model, where radiocaesium is supposed to move downward by convectional mechanisms, is checked using samples from control plots which had been neither amended, nor cultivated since 1928. This simple model presents the advantage of depending on only two parameters: α, a proportional factor allowing the historical atmosph…
Isotopes Trace Biogeochemistry and Sources of Cu and Zn in an intertidal soil
2013
River floodplain soils are sinks and potential sources for toxic trace metals like Cu and Zn. We hypothesize that stable Cu and Zn isotope ratios reflect both the mobilization and the sources of metals. We determined the soil properties, the concentrations and partitioning of Cu and Zn, and variations in δ65Cu and δ66Zn values in a core obtained from an Aquic Udifluvent developed on a freshwater intertidal mudflat of the River Elbe, Germany. The core was sampled at 2 cm intervals to a depth of 34 cm, which corresponds to approximately 9 yr of sedimentation. Elevated concentrations of Cu (up to 320 μg g−1) and Zn (up to 2080 μg g−1) indicated anthropogenic pollution. At the time of sampling …
Quantitative study of the capture of silver nanoparticles by several kinds of soils
2018
The capacity of different soils to capture silver nanoparticles (AgNPs) by measuring changes of an AgNP intrinsic property such as the plasmon for the first time, was studied. In-tube solid-phase microextraction (IT-SPME) coupled on-line to capillary liquid chromatography (CapLC) with diode array detection (DAD) was employed for measuring the interactions between soil and in-contact AgNP dispersions. Its achieved LOD 9 pM assures quantitative retention measurements and selectivity for soil lixiviation was suitable. Electronic microscopy was employed for corroborating the entrapped Ag into the soils. Capture % of AgNPs was calculated in compost (>99%), mountain (>99%), orchard (15±1%) and ur…
Contamination from polycyclic aromatic hydrocarbons (PAHs) in the soil of a botanic garden localized next to a former manufacturing gas plant in Pale…
2010
The Botanical Garden lies within the city of Palermo, a few meters away from one of the largest unused Manufacturing Gas Plant in Sicily. The total concentrations of PAHs (23 compounds) in the soil of Botanical Garden ranged from 947 to 18,072 microg/kg. The wide range of PAH concentrations (RSD=84%) found in the soil samples indicates heterogeneous levels of contamination in the area and this can be explained by considering the different tree distributions which prevents the homogeneous deposition of pollutants on the soil. Soils collected in the Botanical Garden generally showed the highest PAH concentrations, being almost 2-3 times higher than the concentration samples obtained in the ur…
Temporal fatty acid profiles of human decomposition fluid in soil
2017
Abstract We studied the changes in concentration and relative abundance of human-derived fatty acids (FAs) in soil over a period of one year. The study is based on analysis of soil underneath a human body that lay on the soil surface for 18 days before it was discovered. Soil samples were taken when the body was removed, and also 358 days later. Large amounts of the total FA concentration at the start of the measurement period were still present one year after the removal of the body. The FA profile suggested that extensive saturated FA reduction occurred during the first 18 days after deposition. 10-Hydroxystearic acid and FA salts, which are characteristic of adipocere, were abundant in a…
The behavior of Rare-Earth Elements, Zr and Hf during biologically-mediated deposition of silica-stromatolites and carbonate-rich microbial mats
2015
Abstract Venere Lake, in the Pantelleria Island thermal system (Central Mediterranean Sea) consists of a mix of seawater and hydrothermal volcanic fluids containing high levels of dissolved SiO 2 . Close to the lake's thermal springs, siliceous stromatolites are deposed under high bacterial activity conditions whereas roughly interlaminated Ca-carbonates and microbial mats are widely scattered in the lake. The dissolved REE speciation in lake waters is dominated by [REE(CO 3 ) 2 ] − , [REE(CO 3 )] + and [REE(H 3 SiO 4 )] 2 + complexes. On the contrary the most abundant Zr and Hf species are hydroxyl- and fluoride-complexes. The behavior of REE Zr and Hf in the Venere lake waters is controll…
Passive degassing at Nyiragongo (D.R. Congo) and Etna (Italy) volcanoes
2014
Volcanoes are well known as an impressive large natural source of trace elements into the troposphere. Etna (Italy) and Nyiragongo (D.R. Congo) are two stratovolcanoes located in different geological settings, both characterized by persistent passive degassing from their summit craters. Here, we present some results on trace element composition in volcanic plume emissions, atmospheric bulk deposition (rainwater) and their uptake by the surrounding vegetation, with the aim to compare and identify differences and similarities between these two volcanoes. Volcanic emissions were sampled by using active filter-packs for acid gases (sulfur and halogens) and specific teflon filters for particulat…
A christmas gift: Signature of the 24th December 2018 eruption of Mt. Etna on the chemical composition of bulk deposition in eastern sicily
2020
The eruption of Mt. Etna which occurred on December 24th 2018 was characterized by strombolian activity and fire fountains, emitted by the New South-East Crater and along a fissure that propagated towards the SE. The influence of volcanic emissions on atmospheric deposition was clearly detectable at several kilometres from the source. Wet and dry (bulk) deposition samples were collected each month, through a network of eleven collectors, in the areas of Milazzo, and Priolo between June 2018 and June 2019. They were analysed for major ions and trace elements concentrations. The pH values range from 3.9 to 8.3, while the EC values range from 7 to 396 μS cm-1. An extensive neutralization of th…
Diagenesis of speleothems and its effect on the accuracy of 230 Th/U-ages
2014
Abstract Speleothems can be precisely dated by U-series disequilibrium methods. One basic assumption of the 230Th/U-dating method is that the system remains closed and U and Th isotopes are neither lost nor added after deposition. For stalagmites, this requirement is usually fulfilled due to their protected environment in caves. However, undersaturated drip water may lead to diagenesis of speleothem CaCO3 and altered 230Th/U-ages. Here we present a detailed petrographic investigation using thin sections and 230Th/U-ages of a stalagmite from the Riesenberghohle, northern Germany, which grew during Marine Isotope Stages 5e, c and a. The occurrence of a mosaic fabric in large parts of the stal…