Environmental Engineering Reference
In-Depth Information
Lake Mälaren
Lake Mälaren
Lake Trekanten
Lake Trekanten
Ag concentration
0-1
µ
g g
-1
1-5
µ
g g
-1
5-7
µ
g g
-1
>7
µ
g g
-1
W concentration
0-5
µ
g g
-1
5-20
µ
g g
-1
20-30
µ
g g
-1
>30
µ
g g
-1
Lake Björnsjön
(reference)
Lambarfjärden
(upstream)
Archiepelago
(downstream)
Lake Björnsjön
(reference)
Lambarfjärden
(upstream)
Archiepelago
(downstream)
Lake Drevviken
Lake Drevviken
Lake Mälaren
Lake Mälaren
Lake Trekanten
Lake Trekanten
Sn concentration
0-5
µ
g g
-1
5-20
µ
g g
-1
20-30
µ
g g
-1
>30
µ
g g
-1
Sb concentration
0-0.5
µ
g g
-1
0.5-1.5
µ
g g
-1
1.5-2
µ
g g
-1
>2
µ
g g
-1
Lake Björnsjön
(reference)
Lambarfjärden
(upstream)
Archiepelago
(downstream)
Lake Björnsjön
(reference)
Lambarfjärden
(upstream)
Archiepelago
(downstream)
Lake Drevviken
Lake Drevviken
Fig. 2
Distribution of W, Sb, Sn and Ag in Stockholm sediments
number of sampling sites. Concentrations at Kastellholmen, Trekanten and Årstadal
exceed 20 mg/g (Fig.
2
).
Tin concentrations in surface sediments range from 1.2 to 38 mg/g (Fig.
2
).
The lowest concentration was found at Lake Bornsjön and maximum concentra-
tions were measured at Barnhusviken. Average concentrations at Barnhusviken,
Årstadal, Kastellholmen and Saltsjön exceed 25 mg/g.
Silver concentrations range from 0.2 to 8.5 mg/g with the lowest concentrations
at background sites (Bornsjön and Lambarfjärden) and the highest concentrations
in the inner city area (Barnhusviken, Kastellholmen, Saltsjön and Trekanten) (Fig.
2
).
The relatively high Ag concentration in the Archipelago downstream from
Stockholm indicates an export of Ag into the Baltic Sea.
Platinum and Rhodium
Platinum and rhodium concentrations in sediments range from 2.4 to 25 ng/g and
from 0.3 to 5 ng/g, respectively. The lowest concentrations are observed at back-
ground sites (Mälaren and Bornsjön), as well as at the downstream site (Archipelago),
while the highest concentrations were measured in the inner city (Barnhusviken and
Saltsjön) and in Lakes Trekanten and Drevviken (Fig.
3
).
