Groundwater mercury concentrations

Figure 5. Comparison of groundwater mercury concentrations in samples taken from Pallette Lake using the dug-well and acrylic-tube sampling methods.

Mercury is a rare element in the Earth s crust, It is only relatively concentrated in some volcanic areas and in mineral deposits as a trace constituent of ores of other heavy metals. Mercury concentrations in groundwater and surface waters rarely exceed 1 pg/L. 

Standards for the Control of Residual Radioactive Materials from Inactive Uranium Processing Sites-maximum concentration of constituents for groundwater (mercury) 0.002 g/L 40 CFR 192.04 EPA1995e... 

The chemical cycles, while natural, are not necessarily benign. For example, arsenic can leach naturally from rocks and dissolve into groundwater. The concentration of arsenic in that water may be high enough to be toxic to humans, rendering it useless for drinking unless treated. Likewise, mercury can transition from earth to atmosphere... 

The distribution of Hg within seepage lakes is a net result of the processes that control Hg transport between the atmosphere, water column, seston, sediments, and groundwater. This discussion focuses on the processes that control the exchange of Hg between the sediments and lake water. We first present data on spatial and temporal concentrations in the water column, sediments, pore water, and groundwater. These data set the context for a subsequent discussion of the chemical and physical processes responsible for the transport of mercury across the sediment-water interface and are necessary for assessing transport rates. 

In another example [229], atrazine and one of its main by-products (deethylatrazine) have been removed in a large-scale 03/UV plant. The plant was fed with 70 m3 h 1 of groundwater (pH 7.2, 464 mg L 1 bicarbonate and 0.6 mg L-1 DOC). UV-C radiation was emitted from a medium-pressure mercury arc lamp with a maximum total electrical power of 10 kW and 1.2 kW maximum radiant power in the UV-C region. The maximum electrical power of the ozone generator was also 10 kW. Concentrations of atrazine and deethylatrazine in the plant inlet were 0.28 pg... 

High concentrations of mercury may occur in groundwater and surface water supplies in gold-mining areas where mercury has been used for gold extraction,... 

X). If the fluid inside a tree is about 0.1 M more concentrated in solute than the groundwater that bathes the roots, how high will a column of fluid rise in the tree at 25°C Assume that the density of the fluid is 1.0 g/cm3. (The density of mercury is 13.6 g/cm3.)... 

Analysis of the leachates and the groundwater has shown that mercury release to water is very low and would never reach a concentration greater than 0.0001 mg/1 in the forthcoming years if the waste input trend stays the same at the Mare Chicose landfill. 

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