Volatility of mercury

Volatilization is also a dominant transport mode for mercury, which is the most volatile metal in its elemental state. As with lead, a key reaction that can increase the volatility of mercury is formation of an organometallic compound. In this case, the reactions take place in water and are primarily biological, being mediated by bacteria commonly found in the upper levels of sediments. These reactions and their importance in the global mercury cycle are discussed in some detail later in the chapter. 

Zeroual Y, Moutaouakkil A, Blaghen M (2001) Volatilization of mercury by immobilized bacteria (Klebsiella pneumoniae) in different support by using fluidized bed bioreactor. Curr Microbiol 43 322-327... 

Although detectable concentrations for several elements could be found after fusion, it is felt that the volatility of mercury and possibly lead and tin would make their determination by lithium tetraborate fusion questionable. Table I shows the elements selected for analysis and the accuracy and precision data for the standards used to check the fusion method. Each standard in Table I was of known composition and siliceous in nature. The standards were separately prepared 10 times so that a statistical evaluation of the results could be made. The standards used were USGS Standards G-2, W-l, BCR-1, commercially prepared silica-alumina based standards, and unfused synthetic standards prepared by the Coal Research Bureau (9, 10, 11, 12). The synthetic standards were used because no commercially prepared standard having... 

In casework in which discharge residue particles were detected, and in which the ammunition involved is known to contain mercury, very few, if any, of the particles contained mercury. This has been noted over many years and in numerous cases. Possible reasons for this could be the volatility of mercury and its compounds, or decomposition of the mercury fulminate and the loss of mercury through amalgamation with zinc in the primer cup/car-tridge case. It is not uncommon, when firing old ammunition with mercury fulminate primers, for some of the cartridge cases to crack, due to embrittlement of the brass caused by mercury amalgamating with the zinc. 

Removal of heavy metals by algae U4) and volatilization of mercury by Estuarine bacteria 115> from effluents entering the natural environment have been studied. 

Our remaining problems are to determine the radiation stability and volatilization of mercury from Type 2 sludge. We do not believe it possible to keep mercury in the melt, so our eflEorts will be concentrated on efficient removal of mercmy from the oflF-gas. 

The formation of HgS is significant for remediation efforts at the site because the toxicity, leachability, and volatility of mercury in soils are dependent on the solid phase speciation. Because local hydrogeochemical conditions are not unique, the formation of HgS at this site has implications to other environments and contaminated sites as well. 

Volatilization of mercury from gold and silver amalgams. 

In the trace analysis of high-purity zinc, the sample is coated with a thin layer of mercury. After dissolution of the zinc in hydrochloric acid, a drop of mercury remains that contains amalgams of many trace metals from the zinc analysed. They can be determined after volatilization of mercury [103]. 

Seawater and estuarine water CRMs certified for their contents of trace elements (see sections 8.7 and 8.8) were not analysed for mercury. Due to the high volatility of mercury, water to be analysed for Hg content can not be stored in polythene bottles and a higher acidification is necessary. So far, no CRM existed for this element, and hence a separate reference material had to be produced. 

The crucial two-electron reduction step in this pathway is catalyzed by the flavoprotein mercuric ion reductase. The high vapor pressure of elemental mercury results in the volatilization of mercury from aqueous media (Chang et al., 1993 Ogunseitan 1997 Ogunseitan 1998). 

VOLATILIZATION OF MERCURY IN FLUIDIZED BED REACTOR USING IMMOBILIZED AND FREE CELLS... 

Ghosh S., Sadhukan P.C., Chaudhuri J., Ghosh D.K. and Madal A. (1996) Volatilization of mercury by immobilized mercury-resistant bacterial cells. J. Appl. Bacteriol. 81 104-108. 

Magos L, Peristianis GC and Snowden RT (1978b) Postexposure preventive treatment of methyl mercury intoxication in rats with dimercaptosuc-dnic add. Toxicol Appl Pharmacol 45 463 —475. Magos L, Tueerey AA and Clarkson TW (1964) Volatilization of mercury by bacteria. Br J Ind Med 21 294-298. 

In the 1980s, research has been performed on laser-induced AFS (LI-AFS) after electrothermal atomization of metals. No application of this technique for the determination of mercury seems to have appeared, but for several other metals, detection limits 1-2 orders of magnitude lower than for GF-AAS have been reported (Dougherty et al., 1989 Ome-netto, 1989, general review). However, the application of this technique on mercury in biological samples may cause problems, due to the volatility of mercury compounds (see Graphite furnace ). 

Stoichiometric I Te is very difficult to prepare because of the volatility of mercury. 

In addition, volatilization of mercury was found to be an important loss process in the BDW watershed. The magnitude of volatilization appears to be approximately double the direct wet deposition over lake and wetlands, and 27% of the direct wet deposition to the terrestrial catchment. Over the entire basin area the mass of mercury volatilized is 46% of the mass deposited by wet deposition. 

Mercury emissions The high volatility of mercury may cause gaseous emissions, which are not related to dust. In view of the implementation of a European policy on mercury emissions, there is a need for research into the emissions of mercury from melting processes in general and from (non-ferrous) foundries in particular... 

No information is available on volatilization of mercury from either the lake or watershed. There is also no estimate of exchange between lake water and sediment. Vfork is in progress to evaluate these fluxes. Since Cranberry Lake s seasonal thermo-cline is quite deep (lOm), most of its bottom waters are rarely anoxic. (LaRow, unpublished data). Thus, considerable methyla-tion of mercury should be occurring in the bottom sediments. 

Schottel, J., A. Mondal, D. Clark, and S. Silver, 1974. Volatilization of Mercury and Organomercurials Determined by Inducible R-Factor Systans in Entire Bacteria Nature 251, pp. 335-337. 

Most laboratory operations are safe and exposure to chemicals can be safely managed. However, there are incidents in which laboratory workers have been exposed to toxic chemicals and measures of exposure have played a role in understanding the causes of the incidents. While there is a broad variety of laboratory incidents involving many chemicals, one chemical is responsible for more incidents than any other—mercury and its compounds. This is due to the toxicity and volatility of mercury and its compounds. 

The mode of sample pretreatment depends on the analytical method used. If a mineralization of the specimen is required, the high volatility of mercury must always be kept in mind. If necessary, acid digestion at elevated temperatures should only be performed in sealed vessels (e.g., Teflon-or quartz-lined pressure bombs) and never in open vials. A digestion of blood or tissues with hydrochloric acid at room temperature for 15 hr extracts all mercury species sufficiently from the matrix. The supernatant is, for example, suitable for the flow injection technique of cold vapor atomic absorption spectrometry (CV-AAS) [111]. Furthermore, this cold digestion does not destroy organomercury compounds. Therefore the supernatant is suitable for a speciation [110]. 

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