How Filtralite® Is Transforming Water Treatment in Spain – A Model For The Middle East?
Introduction
As the Middle East faces growing water scarcity and increasing demands on aging infrastructure, innovative solutions from around the world offer new hope. Spain, a country with a similarly diverse and challenging water landscape, has taken major strides in water treatment and resource management. At the heart of this progress is Filtralite®, an advanced filtration media developed by Saint Gobain, made of expanded clay that is commonly used in water treatment and filtration processes, now used at the Llobregat Drinking Water Treatment Plant in Barcelona. Expanded clay is a lightweight aggregate material that is produced by heating natural clay to high temperatures, causing it to expand. Filtralite®, in particular, is known for its high porosity, durability, and efficiency in water filtration applications. The Plant Manager, Santiago Gonzalez Avellana, was given the possibility to share what he thinks about Filtralite® products and how they help him in his daily work. This interview reveals how Filtralite® is helping optimize energy use, reduce maintenance costs, and extend filter lifespan — lessons that may prove valuable for water utilities across the Arab region.
Can you describe your career and your current role at ATL?
I am an industrial engineer specializing in industrial chemistry and I have been working for 22 years in the drinking water treatment sector. I became part of the technical team of ATL in 2005 and I have been in charge of the Llobregat Drinking Water Treatment Plant since 2016.
Can you give us some facts and figures about your plant? What solutions did you have for the filtration stage before installing Filtralite®?
The Llobregat Drinking Water Treatment Plant was commissioned around 1978. Currently, it has a maximum production capacity of 3.2 cubic metres per second, and two very different water treatment lines. On the one hand, we have a more conventional treatment that starts with pre-oxidation of the water with potassium permanganate (KMnO4 ), followed by a pH adjustment with carbon dioxide (CO2 ) and a coagulation-flocculation-decantation process. Chlorine dioxide (ClO2 ) is then dosed as an oxidant and the water is passed through a double filtration stage, the first with silica sand as a filter bed and the second through a 150 cm bed of activated carbon grains.
To optimize the filter run and reduce washing costs, Filtralite was tested on an industrial scale on one of the 12 filters of the plant.
The results showed that with the Filtralite® solution, the filtration run times were increased, reducing the number of washes by 66%.
Finally, much of the filtered water goes through advanced treatment, using reverse electrodialysis membranes, prior to final dis- infection and re-chlorination with sodium hypochlorite (NaClO) at the inlet and outlet of the storage tanks. The initial solution implemented to date for the filtration stage was the original one, that is, sand filtration.
How did you learn about the Filtralite® solution and what made you decide to try this innovative filtration media?
In 2017, and after the involvement of Filtralite® technicians with ATL’s re- search, development and innovation department, initial meetings were held to learn about the characteristics and properties of Filtralite® media.
We then assessed the possibility of trying it at the plant, either on a pilot scale or on an industrial scale. In order to optimize the filter run and reduce washing costs, we decided to carry out the test directly on an industrial scale on one of the 12 filters of the plant. Before replacing the existing sand with Filtralite®, it was necessary to adapt the filter by increasing the dis- charge level of the wash water. The performance of Filtralite® was evaluated by operating the filter against a sand filter under equivalent conditions for more than 10 months.
How would you describe the main features of Filtralite® and its advantages compared to your initial solution?
After almost a year of testing, the results obtained showed that with the Filtralite® solution, the filtration run times were in- creased, reducing the number of washes by 66%. This reduction in the number of washes translates into significant economic savings for the operations: savings in the energy consumed while at the same time, the filter operating time increases, thus increasing the treatment capacity. The reduction in the number of procedures with the equipment involved in the washing process reduces the maintenance costs of
such equipment and will extend its useful life.
With the Filtralite® solution it was possible to work with higher filtration velocities than with conventional sand, even exceeding 15 m/h.
Finally, it should be noted that throughout the test it was possible to verify that the water quality obtained using Filtralite® was similar to that provided by sand filters, both in terms of turbidity and in terms of a barrier effect.
Did you encounter any unexpected results, positive or not, during the industrial test performed?
Yes, we did. We were able to verify that with the Filtralite® solution, it was possible to work with higher filtration velocities than with conventional sand, even exceeding 15 m/h while maintaining part of the increase in the filtration runs.
Do you know how much energy you are saving thanks to the Filtralite® solution? What is the estimated return on your investment? Could you give us a more detailed calculation?
In the filter where Filtralite® is installed, we estimate that we are saving about 60% of energy compared to using sand. In addition, by having longer filtration runs, the reduction in the number of washes resulted in a savings of 65% of washing water. Taking these and other aspects into account, we have calculated a return on investment of approximately 2.3 years.
If you had to do it all over again, would you choose Filtralite® again? Would you recommend it to your colleagues?
Yes, indeed. In fact, tests are planned for other ATL production sites to evaluate the performance of this filtering material.
What are the next projects for your plant?
The plant’s next projects are aimed at increasing the production capacity of the plant to 4 cubic metres per second. Two more clarifiers will be built and the 12 sand filters and the 15 activated carbon filters will be remodelled. The sand filter remodelling project includes the replacement of the sand filters with Filtralite®.
What are the characteristics of the current water market in Spain, and more specifically around Barcelona and Catalonia?
I sincerely believe that hand in hand with innovation and technological advances we are moving towards more sustainable and efficient water services, and towards treatments that allow us to obtain higher water quality. All this focused on making the best possible use of water resources that are becoming increasingly scarce.
Spain’s national government has promised a water resources action plan worth 12 billion euros. How will this plan affect you? What do you consider to be the main areas of development?
I believe that the main areas to be developed are the increase in desalination capacity, the use of reclaimed water and the upgrading of existing treatment plants, as well as heavy investments in the digitalisation of the different processes.
Taking into account savings in energy, washing water and other aspects, we have calculated a ROI of approximately 2.3 years.
Mohammed Kastawy Area Sales Manager – MENA Region Mobile: +971565503535 Email : mohammed.kastawy@saint-gobain.com LinkedIn: www.linkedin.com
