Mercury Speciation of MSWI Flue Gas on Pilot and Industrial Scales
403
the investigation. Sampling of mercury was made at post T5, where the
temperature was about 180°C.
2.2
The Savenas MSWI Plant in Goteborg
Measurement was performed at the Siiveniis MSWI plant in Goteborg. The annual
amount of waste treated at this plant is about 300000 tons, of which about 70%
is household waste and the rest is of industrial origin. The plant has been
equipped with modern electrostatic filters for collection of fly ash, and two wet
scrubbers which respectively wash out water-soluble compounds such as HCl,
HF, dioxin, and heavy metals including Hg. Typical concentrations of different
pollutants in flue gas before and after passing through the two wet scrubbers are
summarized in Table 1.
Figure 2 is a schematic diagram of the installation at the Siiveniis MSWI plant
and the sampling points chosen for this investigation. Point C is also where the
plant monitors for other environmental pollutants.
Table 1. Typical concentration of pollutants in flue gas before and after wet scrubber, according to
GRAAB (1993)
Pollutants
HCI
HF
Hg
Dioxin
Flue gas after
electrostatic filter
--'"
"
J:
Before scrubbers
(mg m')
700-1000
1-10
0.05-0.1
2-5 x 10 6
After scrubbers
(mg m- 3 )
0-10
0.1-0.3
0.015-0.025
0.1-0.4 x 10- 6
To chimney
Fig. 2. Sampling points at Siiveniis MSWI Plant in Giiteborg. A before the two scrubbers (160 DC), B
between the two scrubbers (60°C), and C after two the scrubbers (60 DC)