Fluidra implements solutions to improve Catalonia’s aquifers

The multinational group, Fluidra, through its
specialised branch, Astramatic, has undertaken to design and build two water
treatment plants with the aim of reusing the waters from the secondary and
tertiary effluents of the Baix Llobregat Wastewater Treatment Plant (Depurbaix)
and from a leading textile company located in the area of the Tordera aquifer
(Maresme region).
As a result of the agreement between the Catalan Water Agency and the
General Council for the Chambers of Commerce of Barcelona, a study has
been carried out on the reuse of treated waters from the dying and textile
finishes industry, both for internal use (process water) and to supply other
companies. As the successful bidder for the project, Astramatric’s team of
engineers has designed and built a complete plant that is able to deal with a
flow rate of 525 m 3 per hour. This means it will be able to purify 12,600 m 3 per
day, which will make this the largest industrial plant of its kind in Spain and the
second largest in Europe.
The solution consists of a three-step treatment: firstly, a filtration-based pre-
treatment to condition the incoming water (10 completely automatic silex filters);
secondly, ultrafiltration treatment that is highly efficient as a preliminary
treatment to ensure the optimum performance in the following stage; thirdly,
reverse osmosis, through which water is obtained of a quality that is fit for
reuse.
The Baix Llobregat Wastewater Treatment Plant conceived the second project,
which involves the reuse of wastewater. The idea behind this project is to make
new resources available to help solve the problem of the shortage of water for
ecological and environmental uses experienced in Catalonia’s inland river
basins.
The reuse of waters from the Depurbaix plant has been designed to ensure the
environmental flow of the River Llobregat, to replace irrigation flows, to maintain
humid areas and to act as a barrier against saline intrusion.

Due to its close proximity to Barcelona and storage capacity of almost 100 Hm 3 ,
the Llobregat aquifer is of vital strategic importance in supplying Barcelona and
the surrounding metropolitan area with water. For over 20 years the aquifer has
been experiencing saline intrusion, which is concentrated in two salt wedges
that reduce the possibility of using it as regulating reservoir.
In order to overcome this problem, a hydraulic barrier has been designed to
prevent saline intrusion. Astramatic has therefore come up with a design
comprising of three stages: submerged ultrafiltration will be used in the pre-
treatment process; a reverse osmosis facility is being built by Astramatic at the
Depurbaix plant that will enable it to treat an influx of 7,400 m 3 /day, and thus
produce 5,000 m 3 of reusable water every day. Finally, the water will undergo
ultraviolet disinfection, which will eliminate all germs from the water.