Around the globe, communities and industries are facing mounting challenges in securing clean, safe water. Rapid urbanization, climate change, aging infrastructure, and rising energy costs are placing unprecedented pressure on water utilities and treatment plants.
In response, there is a growing demand for sustainable, high-performance filtration technologies that can not only improve water quality, but also reduce environmental and operational burdens.
In this context, Filtralite®, a filtration media brand developed by Saint-Gobain, has emerged as a game-changer. With a focus on innovation, efficiency, and sustainability, Filtralite® offers a range of filter media products tailored to meet the evolving needs of modern water treatment systems. One of its standout products, Filtralite® Clean, is a leading solution for wastewater treatment applications. Let’s have a focus.
What is Filtralite® Clean?
Filtralite® Clean is a high-performance filter media produced from expanded clay aggregates, made through a carefully controlled thermal process that transforms natural clay into a highly porous and lightweight material. This unique structure provides a significantly larger surface area than traditional media, allowing for superior retention of suspended particles and contaminants.
Available in various grain sizes, the product is adaptable to a wide range of filtration setups, whether in mono-media or dual-media configurations. It is especially valued for its longer filter runs, enhanced removal efficiency, and lower frequency of backwashing, all contributing to cost savings and operational resilience.
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Engineered for Performance
Filtralite® Clean is specifically developed for biological treatment and tertiary filtration in wastewater treatment plants. Its unique porous structure offers ideal conditions for biofilm growth and improved water flow through the filter bed. This translates into more contaminants being retained and adsorbed, greater filtration capacity, and significantly reduced operational costs.
In biological reactors, Filtralite® Clean supports both aerobic (nitrification and organic matter removal) and anoxic (denitrification) processes. Its high surface area and void ratio promote robust biomass development, while its mechanical filtering ability efficiently captures suspended solids. These features contribute to a process that is not only more effective but also more durable, boasting a media lifespan of up to 30 years in biological filters.
For tertiary filtration applications, Filtralite® Clean stands out with its high porosity, enabling:
- Lower initial and slower-building head loss
- Higher particle storage capacity
- Extended intervals between backwashes (by
approximately 25%) - Reduced backwash water use and energy consumption
Existing systems using Filtralite® Clean already achieve filtration rates of 15–20 m/h, a benchmark that showcases the media’s superior efficiency.
A Tailored Solution for Every Need
Filtralite® Clean is available in both round and crushed forms, with various grain sizes and densities to suit specific design and performance requirements. These customizable properties make it a versatile solution for a wide range of wastewater treatment settings, from compact urban systems to large-scale municipal installations. Additionally, Filtralite® Clean complements other products in the Filtralite® range, like Filtralite® Pure that’s designed for drinking water treatment.
The Sustainable Choice
Filtralite® media is manufactured by heating clay to around 1200°C, followed by controlled crushing and sieving. This process results in a material that combines low density with high durability, impact resistance, and porosity, hallmarks of a long-lasting and environmentally responsible product. As wastewater treatment facilities evolve to meet the demands of the 21st century, Filtralite® Clean offers a proven, forward-looking solution that supports sustainable water management, operational efficiency, and urban resilience.
Case Study (1): Filtralite® Clean Enhances Wastewater Treatment in Dalian, China
In 2000, the city of Dalian, China, inaugurated a new wastewater treatment plant designed to serve a population of 432,000 people, treating up to 120,000 cubic meters of wastewater per day. To meet the stringent effluent standards set for the facility, a biological treatment system with fixed-bed technology was implemented powered by Filtralite® Clean filter media.
Treatment Process Overview
The treatment process begins with standard pre-treatment, including screening and grit/grease removal. This is followed by primary sedimentation in four tanks using lamellar sedimentation technology.
The core biological treatment system is composed of two stages:
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- First Stage – Organic Matter Removal
- Consists of BOD, COD and SS removal in 12 biofor filters.
- In these filters round expanded clay aggregates, Filtralite® Clean, are used as carriers for the biofilm.
- Process air blowers aerate the filters.
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- Second Stage – Nitrification
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- Another 12 biofor filters, with the same surface area, are dedicated to nitrification.
- These filters use crushed Filtralite® Clean as the filter media.
- Air is supplied by blowers to promote biological activity.
Performance Results
| Parameter | Influent (mg/L) | Required Effluent (mg/L) | Achieved Effluent (mg/L) |
| BOD₅ | 216 | < 10 | 3 |
| COD | 480 | < 40 | 30 |
| SS | 350 | < 10 | 8 |
| NH₄-N | – | < 5 | 1.1 |
These results demonstrate Filtralite® Clean’s effectiveness in consistently surpassing treatment targets, particularly for organic matter and ammonium removal. Approximately 40% of the treated effluent is disinfected with chlorine and reused as industrial water, significantly reducing freshwater demand in the region — a strong step toward circular water use and sustainability.
Case Study (2): How Filtralite® Clean is Helping Keep the Mediterranean Sea Clean
Malta, an island nation surrounded by the pristine waters of the Mediterranean, once faced a critical challenge: the majority of its domestic wastewater was discharged untreated into the sea. In 2005, only 6.4% of household wastewater was being treated, leaving the rest to pollute the marine environment.
To meet the standards of the Urban Wastewater Treatment Directive and the European Regulation on water protection, Maltese authorities embarked on an ambitious mission: to build three modern wastewater treatment plants across the island. One of the most significant was the Malta South Sewage Treatment Plant, located in Ta’ Barkat, Xgħajra.
A National Milestone: 80% of Malta’s Wastewater Treated
Commissioned in January 2011, the Malta South STP was designed to treat 51,000 m³ of sewage daily, covering nearly 80% of Malta’s total wastewater output. This project became a turning point in Malta’s environmental stewardship, vastly improving seawater quality, reducing pollution-related odors, and enhancing the overall health of coastal ecosystems.
The Role of Filtralite® Clean: Biofiltration at its Best
At the core of the treatment process lies 6,000 m³ of Filtralite® Clean, a highly porous and lightweight ceramic filter media tailored for biological wastewater treatment. In this facility, Filtralite® is integrated into BIOFOR®, a compact fixed-bed process developed and patented by Suez, where it’s branded as Biolite®.
This setup includes:
- 12 filters for the removal of organic compounds and nitrogen.
- 8 filters dedicated to denitrification.
Thanks to Filtralite® Clean’s high specific surface area, excellent void ratio, and superior abrasion resistance, it enables the robust development of biofilms that degrade contaminants efficiently and reliably.
Beyond Filtration: A Full Treatment Chain
After biological treatment with Filtralite®, the wastewater undergoes:
- Sand filtration for fine particle and bacterial removal
- UV disinfection to eliminate residual microorganisms
Approximately two-thirds of the treated water is safely discharged into the Mediterranean, while the remaining one-third is reused for agricultural irrigation, supporting sustainable water resource management on the island.
A Model of Eco-Innovation
This project not only highlights Malta’s environmental progress but also illustrates how advanced filter media like Filtralite® Clean can play a crucial role in meeting regulatory standards, promoting water reuse, and protecting natural ecosystems.
By embracing innovative technologies, Malta has transitioned from a nation discharging untreated wastewater to a model of sustainable urban water management and Filtralite® has been central to that transformation.
Mohammed Kastawy Area Sales Manager – MENA Region Mobile: +971565503535 Email : mohammed.kastawy@saint-gobain.com LinkedIn: www.linkedin.com
