Origin Of Hg Research Articles

Environmental inventory of mercury (Hg) for the marine shallow water hydrothermal system at Panarea, Italy

Hydrothermal fluids, hydrothermal gases, porewater and seawater were collected from the La Calcara (LC) hydrothermal area (n = 34). Additional samples were taken at Bottaro North (n = 2), Black Point (n = 3) and Panarea Harbor (n = 3). Total Hg (THg) porewater concentrations ranged from 300 to 6200 pM, while dissolved Hgdiss concentrations were generally lower by two to three orders of magnitude. Hydrothermal fluids had concentrations up to 26,000 pM. Mono- and dimethyl Hg (MeHg) were below detection. Total Hg in the gases (Hggas) ranged from 0.9 to 1899 nmol/m3.The THg concentration correlated positively with temperature (r = 0.86), while Hgdiss did not show any correlation (r = −0.02). The origin of Hg in the study area was interpreted to be hydrothermal. However, a clear trend was absent since ambient temperature porewaters had Hg concentrations as high as those porewaters with elevated temperatures. This was considered to be due to a combination of chemical reactions and complex flow patterns beneath the hydrothermal system. The concentration of Hg in the hydrothermal gases ranged from 0.9 to 1899 nmol/m3. This large range was ascribed to subsurface reactions with H2S and CH4 combined with the presence or absence of a sediment cover.Above the LC area, Hg concentrations were higher than those in Mediterranean seawater, indicating that the hydrothermal discharge adds Hg to the Panarea coastal ocean and its ecosystem. This effect is local regarding seawater chemistry and global Hg budgets since with distance Hg concentrations returned to values as expected for Mediterranean seawater. However, since most, if not all, marine food chains originate in coastal water, hydrothermal Hg may bioaccumulate in a given food chain. With >70 known marine shallow-water hydrothermal systems, this may be a worldwide phenomenon that warrants further study.

New geochemical data for defining origin and distribution of mercury in groundwater of a coastal area in southern Tuscany (Italy)

A geochemical study was conducted in a coastal plain in the Orbetello Lagoon area in southern Tuscany (Italy), acquiring new data on groundwater, lagoon water, and stream sediment for insights into the origin, distribution, and behaviour of mercury in a Hg-enriched carbonate aquifer. The main hydrochemical features of the groundwater are ruled by the mixing of Ca–SO4 and Ca–Cl continental fresh waters of the carbonate aquifer and Na–Cl saline waters of the Tyrrhenian Sea and Lagoon of Orbetello. Groundwater had highly variable Hg concentrations (< 0.1–11 μg/L) that were not correlated with the percentage of saline water, depth in the aquifer, or distance from the lagoon. This excluded the possibility that saline water could be the direct source of Hg in groundwater and responsible for release of the element through interaction with the carbonate lithologies of the aquifer. The origin of Hg in groundwater could be ascribed to the Quaternary continental sediments overlying the carbonate aquifer because i) high Hg concentrations were found in the continental sediments of the coastal plain and in the contiguous lagoon sediments; ii) waters from the upper part of aquifer had the highest Hg concentrations; iii) Hg levels in groundwater increased with increasing thickness of the continental deposits. The high Hg content in the continental and lagoon sediments is geogenic due to regional and local Hg anomalies and to sedimentary and pedogenetic processes. It can be assumed that i) water circulating in these sediments dissolves the solid Hg-bearing constituents and mobilises this element mainly as chloride complexes; ii) Hg-enriched water moves from the upper part of the carbonate aquifer due to the cone of depression generated by intense pumping of groundwater by fish farms in the study area.

Metales pesados en suelos y sedimentos de la zona cañera del sur de Quintana Roo, México

In order to determine the heavy metals content and distribution in an area cultivated with sugarcane in the Río Hondo basin, southern Quintana Roo, Mexico, 10 samples of surficial sediments were collected from the main agricultural drain and 18 samples from soils developed on a karst aquifer. The samples were obtained on february 2016, during the dry season. Concentrations of Hg, Cd, Cu, and Fe and physicochemical parameters such pH, organic matter and cation exchange capacity were measured. In order to understand the distribution of the heavy metals, we performed descriptive statistics, Pearson correlation, analysis of variance, t test, principal component analysis and hierarchical clustering analysis. The mean concentration of heavy metals in soil, in descending order were: Fe &gt; Cu &gt; Cd &gt; Hg with soil values of 25,334.13 mg∙kg-1, 10.56 mg∙kg-1, 0.55 mg∙kg-1 and 0.02 mg∙kg-1, respectively; the sediment values found were 19,952.68 mg∙kg-1, 8.00 mg∙kg-1, 0.54 mg∙kg-1 and 0.06 mg∙kg-1, respectively. The physical and chemical parameters were homogeneous within the study area. The origin of Hg, Cd and Cu concentrations could be anthropogenic. Although Fe is naturally found in the study area, it is possible that the current distribution of this metal is also due to agricultural activity. The main factor in the distribution of heavy metals in the agricultural soils of the sugarcane zone is the carrying of soil particulates caused by runoff, and the greater contribution of these pollutants to the agricultural drain occurs mainly by the entrainment of particulates from gleysol type soils.

Mercury and Chlorine in the Balingian Coal from Sarawak, Malaysia

There are growing concerns regarding human and environmental health from the release of Hg and Cl during coal combustion. These two elements are potentially hazardous trace elements and so their emissions from coal combustion must be reduced to protect public health. However, information about Hg and Cl is usually lacking to both policy makers and coal users in many countries using coal for energy. The objective of this study was to understand the concentration, modes of occurrence, and the origin of Hg and Cl in the Balingian coal. Mercury content in the Balingian coal ranges from <1 to 22 ppb with an arithmetic mean of 8 ppb, while Cl content varies from 100 to 209 ppm with an arithmetic mean of 139 ppm. The Balingian coal is highly depleted in Hg but it is enriched in Cl, with respect to the Clarke values of these elements. Mercury is mostly organically bounded in the studied section at sampling sites B01 and B03; however, it is mostly inorganically bounded in the studied section at sampling site B02. While Hg in the studied section at sampling sites B01 and B02 has been epigenetically emplaced from overlying rocks by descending groundwater carrying Hg in solution, it has been emplaced syn-genetically in the studied section at sampling site B03. Chlorine is mostly inorganically bounded in the studied section at sampling sites B01 and B02; however, it is mostly organically bounded in the studied section at sampling site B03. Chlorine is mostly syngenetic in origin in all the three studied sections; however, Cl at the lower part of the studied section at sampling site B01 has been emplaced by epigenetic source.

Discovery of Cinnabar in Soils in Hg Anomalous Zones in City and Town Areas and Their Surroundings and Its Significance

Abstract As a result of systematic study on heavy minerals in soils at city and town areas and their surroundings, cinnabar was discovered for the first time in areas of Hg anomalies in China, and it was found that the distribution of cinnabar was basically coincident in scope with that of Hg anomalies, showing that Hg anomalies were closely related to cinnabar. This finding provides a theoretical basis for a verification of Hg anomalies in soils in city and town areas and their surroundings, as well as evaluation of its ecological effects, and is significant to revealing the occurrence modes and origin of Hg in soils.

Relation between mercury concentration and water discharge in the Katun River, Siberia

Some results of a study of the pattern of mercury (Hg) occurrence in the Katun River were used to identify the main origin of Hg in the water. A relatively simple method based on statistical analysis of concentration-discharge and load-discharge relationships was applied. The behaviour of these curves is quite different for flows polluted by sources of different origins, making it possible to separate the loads caused by point and diffuse sources. The results do not show a clear prevalence of point Hg sources, at least for hydrological periods when the water discharges are close to annual average values or higher. The results do reveal that, for the Katun River, a particular mining activity (i.e. an Hg smelter) on a tributary is not the dominant Hg source and that the contribution to the river load of surface runoff washing off Hg from the whole drainage basin may be significant.