Volatilization, methylation, and demethylation of mercury in a mercury-contaminated stream

Conference · Sun Jan 01 04:00:00 EST 1989

OSTI ID:5729356

Turner, R R; VandenBrook, A J; Barkay, T; Elwood, J W

Radiolabeled mercury compounds introduced into water and sediment samples from a mercury-contaminated stream in Oak Ridge, Tennessee, USA, exhibited both abiotic and biotic transformations. Abiotic reduction of mercuric ion accounted for 10 to 70% of the volatilization of elemental mercury from water samples. Biotic reduction and volatilization increased in warmer months and proceeded rapidly without a lag period. Biotic methylation of mercuric ion was unexpectedly low (<0.2% of added mercuric was methylated in 2 days) and was consistently detectable only in water samples with added sediment (1% solids). Although the presence of sediment appeared to promote methylation of added mercuric ion, one experiment with radiolabeled sediment showed that sediment-bound mercury was essentially unavailable for methylation. Biotic demethylation of introduced methylmercury chloride in water samples was very efficient (>90% of the radiolabeled spike was demethylated and evolved as elemental mercury in <5 days). Although demethylation capacity was high in samples from the study stream, net production of methylmercury was unexpectedly low primarily because the substrate for methylation, mercuric ion, is rapidly lost from the solution phase by reduction and volatilization, and by adsorption to suspended sediment. 4 figs.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5729356
• Report Number(s): CONF-890975-2; ON: DE89014099
• Country of Publication: United States
• Language: English

Related Subjects

520101 -- Environment
Aquatic-- Basic Studies-- Radiometric Techniques-- (-1989)
520200* -- Environment
Aquatic-- Chemicals Monitoring &amp; Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCONVERSION
CHEMICAL REACTIONS
DAYS LIVING RADIOISOTOPES
EVAPORATION
EVEN-ODD NUCLEI
HEAVY NUCLEI
ISOTOPES
LABELLED COMPOUNDS
MERCURY 203
MERCURY COMPOUNDS
MERCURY ISOTOPES
MERCURY NITRATES
METHYLATION
METHYLMERCURY
NITRATES
NITROGEN COMPOUNDS
NUCLEI
ORGANIC COMPOUNDS
ORGANIC MERCURY COMPOUNDS
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
POLLUTION
RADIOISOTOPES
WATER POLLUTION