Chemical speciation of mercury in a highly contaminated aquatic ecosystem: The Carson River of Nevada

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:37444

Bonzongo, J C; Lyons, W B; Warwick, J J; Miller, J ^[1]

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1. Univ. of Nevada, Reno, NV (United States). Center for Environmental Sciences and Engineering

During the 30-year peak (1865--1895) of Comstock mining (near Virginia City, Nevada), the extraction of precious metals accomplished by an efficient and crude amalgamation process, in which mercury was used to free the gold and silver, generated an approximate loss of mercury to the environment of 7,000 tons. A significant portion of these losses has directly or indirectly entered the Carson River, where total mercury [Hg{sub T}] (reaching up to 600 ng/L) and mono-methyl mercury [MeHg] (6% of total mercury in average) determined in water samples collected at different locations along the Carson River were among the highest values worldwide. Chemical speciation of inorganic mercury showed a high potential of its loss from the water column to the atmosphere by volatilization. The influence of temperature, pH, dissolved oxygen, dissolved organic carbon, sulfate, sulfide, and chloride on mercury speciation were examined. A substantial flux of dissolved [Hg{sub T}] was detected at the water-oxic contaminated sediment interface at epilimnetic locations, suggesting that deposited sediments are still a pollutant source for aquatic organisms.

• OSTI ID: 37444
• Report Number(s): CONF-9410273--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CHLORIDES
ECOLOGICAL CONCENTRATION
ENVIRONMENTAL EFFECTS
MERCURY
METHYLMERCURY
NEVADA
RIVERS
SULFATES
SULFIDES
WATER CHEMISTRY
WATER POLLUTION