Galapagar-Torrelodones Wastewater Treatment Plant: Environmental Excellence With Filtralite® Clean

Filtralite® Clean filter media’s special porosity provides ideal conditions for biofilm formation and water flow through the filter bed, which helps to retain and eliminate more pollutants. Larger amounts of water may be filtered through the same volume as the contact area increases because to this feature, which is the primary attribute of the lightweight expanded clay material. Additionally, our products lower operating expenses.

Project Background

The Galapagar-Torrelodones WWTP, operated by Canal de Isabel II, is located within a Natura 2000 protected area in Spain, which enforces some of the strictest European standards for effluent discharge, sludge management, and odor control.

Capacity and Expansion

Commissioned in 2002 with a treatment capacity of 15,000 m³/day, the plant was expanded in 2014 to reach 22,500 m³/day, treating the equivalent load of approximately 90,000 inhabitants.

Treatment Process – The Role of Filtralite® Clean

Instead of conventional activated sludge, the secondary treatment relies on biological filtration with Filtralite® Clean. Thanks to its unique porosity and surface area, the media enhances biofilm growth, ensures efficient contact time, and allows the filters to recover quickly after intensive hydro-air backwashing.

Process Stages

1. Pumping raw water to treatment elevation.

2. Pre-treatment with grit and screenings removal.

3. Reactors and primary sedimentation with lamella clarifiers.

4. Two stages of biological filtration:

   • Anoxic filtration for denitrification (6 filters).

   • Aerobic filtration for nitrification and polishing, with recirculation between the stages.

5. Sludge stabilization with lime and centrifugation.

Key Advantages of Filtralite® Clean

• Space-saving design: No secondary settling needed, reducing footprint by up to 80%.

• Odor & noise control: Filters housed indoors with up-flow design.

• Lower chemical use: Reduced flocculant and disinfectant consumption (up to 30% less disinfectant).

• Stable biofilm: Microorganisms remain attached to the media, only released during backwashing.

• Rapid start-up: Full biological performance within a few days—ideal for fluctuating loads.

• Simplified operations: Modular, automated system with fewer process variables to monitor.

• Reduced OPEX: Lower demand for energy, water, and chemicals.