Compliance achieved
E.COLI
5.5 cfu / 100ml
average in 2025
CHLOSTRIDIUM
19 cfu / 100ml
average in 2025
COLIFAGES
39 cfu / 100ml
average in 2025
Advanced wastewater disinfection in Figueres, Spain
Article takeaways
Extreme drought in Catalonia made treated wastewater a major share of river flow, highlighting the urgent need for reliable, high-performance wastewater disinfection to protect downstream water use.
Fisersa implemented KemConnect® DEX to restore the extracted flow from the Muga River to a quality suitable for irrigation, groundwater extraction for drinking water, and maintaining the ecological flow.
The performic acid-based solution delivers powerful pathogen removal without harmful by-products, offering a more sustainable alternative to chlorine and a lower-energy option than UV systems.
Seamless integration and fully automated operation make KemConnect® DEX a practical, cost-efficient upgrade – helping wastewater treatment plants improve resilience, compliance, and long-term water security.
A critical water source under pressure
In Figueres, a municipality of approximately 50,000 inhabitants in Catalonia, the Muga River is a vital freshwater resource. It supplies drinking water and supports local agriculture, while also receiving treated effluent from the municipal wastewater treatment plant operated by Fisersa. During periods of extreme drought, treated wastewater can account for more than 70% of the river’s flow. This significantly increases the importance of ensuring high-quality effluent, as it directly impacts downstream water uses, including irrigation and drinking water abstraction.
A forward-looking approach to water quality
To safeguard water quality and support long-term water resilience, Fisersa, in collaboration with the Catalan Water Agency (ACA), evaluated several alternatives to enhance disinfection at the Figueres wastewater treatment plant.
Their objective was clear:
• Ensure consistent compliance with strict disinfection standards
• Enable safe reuse for irrigation
• Protect drinking water sources
• Preserve the ecological balance of the receiving water body
Following this evaluation, Fisersa implemented KemConnect® DEX — marking the first installation of this technology in Spain.
The need to find an alternative to our current disinfection method – without generating disinfection by-products and while achieving high pathogen removal rates without increasing the organic load in treated water – led us to select Kemira’s KemConnect® DEX. The unit’s user-friendly operation, Kemira’s support during implementation, and its high performance at low dosing rates have reinforced our decision. Environmental protection, particularly the preservation of our natural water resources, is a top priority for Fisersa as a service
company.
Raül Lattre
Wastewater treatment plant Manager in Fisersa
Innovative disinfection with KemConnect® DEX
KemConnect® DEX is an advanced disinfection solution based on the on-site generation and application of performic acid. Applied at the final stage of wastewater treatment, it provides highly effective inactivation of pathogens and removal of micropollutants, including E. coli.
The solution delivers several key advantages for municipal operators:
- High disinfection performance — Reliable elimination of harmful microorganisms, ensuring compliance with stringent water quality standards.
- No harmful residuals — Performic acid naturally decomposes into water and carbon dioxide, avoiding the formation of harmful disinfection by-products associated with traditional solutions such as chlorine.
- Low energy consumption — Compared to energy-intensive alternatives like UV systems, KemConnect® DEX supports more energy-efficient plant operations.
- Sustainability-driven design — The solution aligns with circular water management principles by enabling safer water reuse and minimizing environmental impact.
Seamless integration and operational simplicity
At the Figueres wastewater treatment plant, KemConnect® DEX was integrated as an additional treatment stage within the existing process. The system’s compact footprint and fully automated operation enabled smooth implementation without disruption to plant operations.
This makes KemConnect® DEX not only a high-performing disinfection solution, but also a practical and efficient choice for modern wastewater treatment plants.
Compact on-site performic acid generator system
With KemConnect® DEX, Fisersa has taken a significant step forward in preserving natural water resources.The absence of disinfection by-products, combined with dosage optimization conducted at the wastewater treatment plant and the solution’s low energy consumption, enables the achievement of appropriate water quality for reuse. At Kemira, we celebrate this collaboration as a strong example of sustainable and responsible water management.
Joan Gómez
Sales representative, Kemira
Supporting resilience in a changing climate
Public awareness around water-related challenges is growing rapidly. Kemira ́s Water Index report offers rankings of 10 European countries and 10 US states from the most to least water resilient. According to the Water Index:
- 98% of people in Spain are concerned about climate-related impacts in their region
- 85% believe more action is needed to prepare for future droughts
- 84% see a need to strengthen resilience against flood events
These figures underline the urgency for municipalities to adopt solutions that improve water security and system resilience. [Kemira Water Index]
Enabling sustainable water management
The Figueres case demonstrates how advanced disinfection technologies can help utilities respond to increasing environmental pressures while maintaining high operational standards. By adopting KemConnect® DEX, Fisersa has strengthened its ability to:
- Protect critical water resources
- Enable safe water reuse
- Reduce environmental impact
- Improve operational efficiency
As water scarcity and regulatory requirements continue to intensify across Southern Europe, solutions like KemConnect® DEX offer a reliable pathway toward more resilient and sustainable wastewater management.
