Mercury, anthropogenic releases

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. 

There are three prominent processes that release mercury of mixed natural and anthropogenic origin to the atmosphere. These three include biomass burning (deliberate and natural) and the evasion of mercury from soils and the ocean. The general factors controlling emission of mercury from soils have been discussed in the section on low-temperature volatilization. The mercury... 

Mercury is released to the environment by both natural processes (e.g., volcanic activity and weathering of mercury-containing rocks) and anthropogenic sources. Anthropogenic releases are primarily to the... 

Tab. 17.3 Important sources of anthropogenic releases of mercury (UNEP 2002)...

Mercury-cell caustic carries the incidental hazard of its mercury content. The hazards of mercury are the subject of Section 16.2.6. Filtration of caustic to remove mercury is part of the subject of Section 9.3.2.6. With proper handling, the mercury content of filtered caustic is quite low, and according to the Environmental Protection Agency (ERA) of the United States [15], all the mercury in NaOH and KOH solutions amounts to less than 0.2% of the total anthropogenic release. 

Anthraquinonoid soluble dyes, 7 373t Anthrone soluble dyes, 7 373t Anthropogenic mercury releases, trends in, 16 47-49 Anthropogenic silicas and silicates, 22 451-480... 

Mercury releases, anthropogenic, 16 47-49 Mercury removal, 1 650 Mercury sulfide (cinnabarite), color and bad gap, 7 335t... 

A more detailed estimate of national mercury emission rates for various categories of sources is shown in Table 5-4. As shown in this table, point sources of anthropogenic mercury emissions appear to represent the greatest contribution of mercury releases, with combustion sources representing 85% of all emissions. 

Natural weathering of mercury-bearing minerals in igneous rocks is estimated to directly release about 800 metric tons of mercury per year to surface waters of the earth (Gavis and Ferguson 1972). Atmospheric deposition of elemental mercury from both natural and anthropogenic sources has been identified as an indirect source of mercury to surface waters (WHO 1991). Mercury associated with soils can be directly washed into surface waters during rain events. Surface runoff is an important mechanism... 

Reducing or eliminating anthropogenic mercury releases will require the control of releases from mercury-contaminated raw materials and feedstocks, as well as reducing or eliminating the use of mercury in products and processes. 

Anthropogenic sources related to the intentionally use of mercury in products and processes, due to releases during manufacturing, leaks, disposal or incineration of spent products. 

Re-mobilization of historic anthropogenic mercury releases, previously deposited in soils, sediments, water, landfill and waste and tailing piles. 

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