Mercury content

Ore. The assay of mercury ores is not simple, owing to the difficulties encountered in obtaining representative ore samples. Crystalline cinnabar is extremely brittie causing it to break loose from adjacent rock and fall into the sample being collected. This uncontrollable salting of the sample can give results as much as several hundred percent over the actual mercury content of the sample. 

Neutron Activation Ana.lysis, A measured sample activated by neutron bombardment emits gamma rays that are used to determine the mercury content by proton-spectmm scanning. Mercury concentrations as low as 0.05 ppb have been determined by this method. 

X-Ray Methods. In x-ray fluorescence the sample containing mercury is exposed to a high iatensity x-ray beam which causes the mercury and other elements ia the sample to emit characteristic x-rays. The iatensity of the emitted beam is directly proportional to the elemental concentration ia the sample (22). Mercury content below 1 ppm can be detected by this method. X-ray diffraction analysis is ordinarily used for the quaUtative but not the quantitative determination of mercury. 

Regulations. In order to decrease the amount of anthropogenic release of mercury in the United States, the EPA has limited both use and disposal of mercury. In 1992, the EPA banned land disposal of high mercury content wastes generated from the electrolytic production of chlorine—caustic soda (14), accompanied by a one-year variance owing to a lack of available waste treatment faciUties in the United States. A thermal treatment process meeting EPA standards for these wastes was developed by 1993. The use of mercury and mercury compounds as biocides in agricultural products and paints has also been banned by the EPA. 

The State of New Jersey has passed a law restricting the sale and disposal of batteries (qv) containing mercury, requiring manufacturers to reduce the mercury content of each battery to 1 ppm by weight by 1995, and to estabhsh a collection program for spent batteries (14). Another New Jersey law bans the sale of products having cadmium, mercury, or other toxic materials in the packaging (14) (see Cadmiumand cadmium alloys Cadmium compounds Mercury compounds). 

Batteries. Many batteries intended for household use contain mercury or mercury compounds. In the form of red mercuric oxide [21908-53-2] mercury is the cathode material in the mercury—cadmium, mercury—indium—bismuth, and mercury—zinc batteries. In all other mercury batteries, the mercury is amalgamated with the zinc [7440-66-6] anode to deter corrosion and inhibit hydrogen build-up that can cause cell mpture and fire. Discarded batteries represent a primary source of mercury for release into the environment. This industry has been under intense pressure to reduce the amounts of mercury in batteries. Although battery sales have increased greatly, the battery industry has aimounced that reduction in mercury content of batteries has been made and further reductions are expected (3). In fact, by 1992, the battery industry had lowered the mercury content of batteries to 0.025 wt % (3). Use of mercury in film pack batteries for instant cameras was reportedly discontinued in 1988 (3). 

Amalgams made with spherical particles may predominate ia use over those made with flake-shaped particles because the desirable plasticity is obtained with a lower mercury content, satisfactory compaction is achieved with lower packing pressures, and there is less influence of manipulative variables upon values for appropriate physical properties. 

To 50 cc of a carefully purified aqueous solution of the sodium salt of N(7-chloromercuri-)3-methoxy-propyl)-d-a-camphoramic acid containing 40 mg of mercury per cc is added 10 cc of a solution containing 1.14 g (1 mol equivalent) of sodium thioglycollate and the mixture is then evaporated to dryness at room temperature and reduced pressure in the presence of a desiccant. The product is an amorphous white powder which decomposes at 156° to 158°C (uncorr,), and which was found on analysis to have a mercury content of 33.0%, according to U.S. Patent 2,576,349. 

The loss of active zinc and the evolution of hydrogen, causing an intolerable rise of internal pressure, were retarded by amalgamation of zinc particles. For quite long time (up to about 1982) mercury contents of 6% (in some cases up to 8%) were regarded as normal [21]. Then a rapid decrease in the mercury content took place (Fig. 1). 

For a couple of years 0.25% Hg became the technical standard. It has to be pointed out that the mercury content of the metallic zinc has to be divided by a factor of roughly 10 to give the mercury content based on the total cell weight of an AA (LR-6) cell. These values are sometimes indicated on the cell labels. With decreasing amalgamation, other corrosion inhibitors had to take over the role of mercury. There are numerous papers and patents claiming corrosion-inhibiting activities of elements like A1, In, T1, Cd, Ga, Na, ... 

Figure 1. Decrease in mercury content of zinc powders within about ten years...

Kinkead, J.D. Hamdy, Y. Trends in the Mercury Content of Western Lake Erie Fish and Sediment, 1970-1977 Ontario Ministry of the Environment, Toronto, Ontario, 1978, 19p. 

Francesconi KA, Lenanton RCJ. 1992. Mercury contamination in a semi-enclosed marine embayment organic and inorganic mercury content of biota, and factors influencing mercury levels in fish. Mar Envhon Res 33 189-212. 

Haines TA, Komov VT, Matey VE, Jagoe CH. 1995. Perch mercury content is related to acidity and color of 26 Russian lakes. Water Air Soil Pollut 85 823-828. 

Beig W, Johnels A, Jostrand BS, Westeimark T. 1966. Mercury content in feathers of Swedish birds from the past 100 years. Oikos 17 71-83. 

Meyer MW, Evers DC, Daulton T, Braselton WE. 1995. Common loons (Gavia immer) nesting on low pH lakes in northern Wisconsin have elevated blood mercury content. Water Air Soil Pollut 80 871-880. 

Miura K, Koyama T, Nakamura I. 1978. Mercury content in museum and recent specimens of Chiroptera in Japan. Bull Environ Contam Toxicol 20 696-701. 

Electrum and cinnabar occur in the same part of the vein, suggesting that these minerals were in equilibrium. The following reaction can be used to determine which factors are important for controlling mercury content of electrum in equilibrium with cinnabar ... 

Donais MK, Saraswati R, Mackey E, Vangel MG, Levenson MS, Mandic V, Azemard S, Hor-VAT M, Burow M, Emons H, Ostapczuk P, and Wise SA (1997) Certification of three mussel tissue Standard Reference Materials (SRMs) for MeHg and total mercury content. Fresenius J Anal Chem 358 424-430. 

Waste halogen and sulfur content Waste lead and mercury content... 

The results in Fig. 1.2 show values between 0.06 and 0.12nmol/kg. The average mercury contents obtained by pumping, Niskin sampler, Go-Flo sampler, and the close-open-close device are 0.09 0.01,0.08 0.03, and 0.10 0.02 nmol/kg, respectively. 

There is a strong relationship between the food of birds from Minamata and the mercury content in feathers the content is highest in fish-eating seabirds and lowest in herbivorous waterfowl (Doi et al. 1984 Table 5.4). This same relationship held in birds collected from China and Korea,... 

Tokuyama Bay, Japan, received 6.6 metric tons of mercury wastes between 1952 and 1975 in wastewater from two chloralkali plants, although sediment analysis suggests that as much as 380 tons of mercury were released (Nakanishi et al. 1989). Unlike Minamata Bay, however, there were no human sicknesses reported, and the hair of residents contained 0 to 5 mg Hg/kg FW vs. 15 to 100 mg Hg/kg FW in Minamata residents. In 1970, a maximum concentration of 3.3 mg total Hg/kg FW was reported in tissues of Squilla, a crustacean. In 1973, a health safety limit was set of 0.4 mg total Hg/kg FW in edible fish and shellfish tissues with a maximum of 0.3 mg methyl-mercury/kg FW permitted at least five species of fish had more than 0.4 mg total Hg/kg FW, and fishing was prohibited. Contaminated sediments (>15 mg total Hg/kg) were removed by dredging and reclamation between 1974 and 1977. By 1979, the mercury content of all fish, except one species, was less than 0.4 mg total Hg/kg FW fishing was prohibited. By 1983, all fish and shellfish contained less than 0.4 mg Hg/kg FW and fishing was allowed (Nakanishi et al. 1989). 

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