COMBINED WATER
TREATMENT AT
VESTFORBRÆNDING
Götaverken Miljö AB has built a combined water treatment plant
on behalf of I/S Vestforbrænding.
In the plant, scrubber water from four flue lines with a total flue-gas flow of
approximately 400,000 Nm
3
/h is cleaned. The water treatment plant processes
both the acid and the alkaline scrubber water, and includes gypsum formation,
gypsum dewatering and ash stabilisation with sulphide sludge.
Process description
The flue-gases from the incineration lines 1-4 are
Limit values - Water quality
pH min/max
-
6.5/9.0
cleaned in the existing scrubbers installed by
Suspended substances
mg/l
30
Götaverken Miljö AB in 1992. At the request of I/S
Total cyanides
mg/l
1
Vestforbrænding, Götaverken Miljö AB has up-
Pb
mg/l
0.1
graded the plant with a total water treatment system
Cd
mg/l
0.003
comprising two identical lines. The combined water
Cr
mg/l
0.3
treatment cleans the output water from both acid
Cu
mg/l
0.5
and alkaline scrubbers. During the treatment
Hg
mg/l
0.003
process, controlled gypsum formation takes place
Ni
mg/l
0.25
in a separate process stage, with subsequent
Ag
mg/l
0.25
Zn
mg/l
1.5
gypsum dewatering. For gypsum formation, the
Tl
mg/l
0.05
neutralised acid scrubber water is used, which is
As
mg/l
0.15
mixed with the output water from the alkaline
Sulphate (SO
42-
)
mg/l
2000
scrubbers. Nominal gypsum production is 230 kg/h
Dioxins & furans
ng/l
0.3
based on
100% TS. Following the gypsum
separation, the water is treated with precipitation
and flocculation chemicals, with subsequent
filtration. Sludge from the precipitation stage is
used to stabilise the fly ash with the ”Bamberg
method”.
Flue-gas fan
From baghouse filter
Quench/Acid scrubber SO
2
scrubber
Ca(OH)
2
CaCO
3
M
M
M
M M
M
M
M
Neutralisation
Precip. &
Filtration
Gyps. reaction
Flocculat.
M
& measure-
MEASUR-
Ash
M
ment
ING BOX
Gyps.
M
Gypsum
Ash stabilisation
dewatering
GÖTAVERKEN MILJÖ AB
Postal address
•
Box 8876, SE-402 72 Göteborg, Sweden Visiting address
•
Anders Carlssons gata 14
Tel +46-31-50 19 60
•
Fax +46-31-22 98 67
www.gmab.se
