Systems Analysis of Zaragoza Urban Water - SWITCH - Managing ...

Systems Analysis of Zaragoza UWS
Guillermo Penagos
Table 4. Zaragoza public WWTPs
WWTP Cartuja
Almozara
Parameter
Sewage Origin Industrial and domestic Industrial and domestic
Average flow at design
3.00 0.40
(m 3 s -1 )
Average actual flow in
1.72 0.37
2006 (m 3 s -1 )
Water treatment
Primary sedimentation, Biological Primary decantation, Biological
treatment by activated sludge and treatment by activated sludge and
secondary decantation
secondary
decantation,
Phosphorus removal with Iron
Chloride
Sludge treatment Primary and secondary digestion
plus dehydration by filter press
Centrifuge dehydration flowed by
incineration
As it can be seen in table 4 “Almozara” is working near its actual capacity whereas
“Cartuja” seems to be over dimensioned and is working at half of its actual capacity.
4.3 Environmental performance of Zaragoza UWS
4.3.1 Use of chemical products
Figure 7 shows the annual consumption of chemical products by Zaragoza UWS
from 2000 for DWT and from 2001 for WWT. There is a steady trend over these
years, but Chlorine and Allum shows a clear reduction for 2005 and 2006, from
around 3000 to 2500 ton and from 8000 to 6000 ton respectively. PAC use for DWT
started in 2003 and it has not been steady since then.
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