Distribution, Bioavailability and Speciation of Mercury
Addition of
HNOJ + I
and Reduction by SnCI;,:
(DIN 38406E12)
j
Hg (total)
Water Samples
No Addition of
Preservatives
(0,45 ~m Filtralion)
No Pretreatment
Stripping of Hg·
j
Reduction
by SnCI.
noOxidalion
1
HgO
Hg IIFig. 2. Determination of operationally defined Hg-fractions
0.45 Ilm Filtralion
I
Oxidation by BrCI and
Reduction by SnCI,
(DIN 38406E12)
1
dissolv_ Hg (total)
No Addition of
Preservatives
GC-Anal.
187
(lnst. of Envir. Geochem ..
Heidelberg)
1
1
Organomercurials
The operationally defined HgIIa-u. HgIIb-fractions are then (Hempel et al.
1992):
HgIIa = sum of dissolved metallic or elemental, easy reducible monovalent and
divalent inorganic mercury.
HgIIb = calculated difference between total mercury contents and HgIIa. This
fraction is said to include organomercurials, organic Hg complexes and
colloidal Hg forms.
2.2.7
Operationally Defined Hg Fractions in Groundwater
As described for the eluate investigations, the Hg fractions HgIIa, HgIIb and Hgo
were also determined in the groundwater. Filtration by a 0.45-~lm membrane
filter was to assist in distinguishing between particulate (per definition) and
dissolvedl colloidal Hg, respectively. By determination of Hgo prior to and after
filtration, the evaporation effect had to be taken into account.
3
Geology and Hydrogeology
Under a 1-3-m-thick artificial fill consisting of redeposited loess/loess loam and
partly building rubble, homogenous loess is encountered down to 5-6 m depth
representing the top layer. These slightly clayey, calcic silt sediments
[pH(H2 0) = 6.9-8.7] possess a comparatively low content of organic carbon
Addition of
HNOJ + I
and Reduction by SnCI;,:
(DIN 38406E12)
j
Hg (total)
Water Samples
No Addition of
Preservatives
(0,45 ~m Filtralion)
No Pretreatment
Stripping of Hg·
j
Reduction
by SnCI.
noOxidalion
1
HgO
Hg IIFig. 2. Determination of operationally defined Hg-fractions
0.45 Ilm Filtralion
I
Oxidation by BrCI and
Reduction by SnCI,
(DIN 38406E12)
1
dissolv_ Hg (total)
No Addition of
Preservatives
GC-Anal.
187
(lnst. of Envir. Geochem ..
Heidelberg)
1
1
Organomercurials
The operationally defined HgIIa-u. HgIIb-fractions are then (Hempel et al.
1992):
HgIIa = sum of dissolved metallic or elemental, easy reducible monovalent and
divalent inorganic mercury.
HgIIb = calculated difference between total mercury contents and HgIIa. This
fraction is said to include organomercurials, organic Hg complexes and
colloidal Hg forms.
2.2.7
Operationally Defined Hg Fractions in Groundwater
As described for the eluate investigations, the Hg fractions HgIIa, HgIIb and Hgo
were also determined in the groundwater. Filtration by a 0.45-~lm membrane
filter was to assist in distinguishing between particulate (per definition) and
dissolvedl colloidal Hg, respectively. By determination of Hgo prior to and after
filtration, the evaporation effect had to be taken into account.
3
Geology and Hydrogeology
Under a 1-3-m-thick artificial fill consisting of redeposited loess/loess loam and
partly building rubble, homogenous loess is encountered down to 5-6 m depth
representing the top layer. These slightly clayey, calcic silt sediments
[pH(H2 0) = 6.9-8.7] possess a comparatively low content of organic carbon