Skip to content


Water management

Water in industries

UV systems for the largest land-based RAS eel system in the world

3. October 2023

Solution provider

ULTRAAQUA UV Disinfection Systems

ULTRAAQUA is an international manufacturer of advanced UV water disinfection systems for a wide range of water treatment applications.

More from ULTRAAQUA UV Disinfection Systems

Want to see this solution first hand?

Add the case to your visit request and let us know that you are interested in visiting Denmark

Request Visit


The client, located in Nanping, Fujian Province in China, aimed to build the largest land-based RAS eel system in the world. The location was chosen for its rich natural resources, proximity to freshwater sources, and high air quality.

The goal was to utilize advanced technology from both China and Europe to meet sustainability requirements and protect the environment. The project had a substantial budget of 268 million EUR and covered an area of 0.53 square kilometers.

It aimed to involve its own industry chain, including RAS aquaculture, eel deep processing, feed production, logistics, and an R&D center.


The project was divided into two phases: the first phase aimed to reach an annual production of 6,000 tons of eels, and the second phase aimed to reach 15,000 tons of eels. The project incorporated a state-of-the-art RAS technology system that included engineering, biology, and aquacultural environmental protection. This system ensured excellent water quality for the eels to thrive by including physical filtering, biological purification, and disinfection.

The facility was equipped with advanced equipment like control and alarm systems, water quality monitoring systems, and an automatic online monitoring system to control temperature, dissolved oxygen, pH, etc. A database system was also set up to record and output all operation data for testing and analysis.


The project marked a new chapter of eel aquaculture in China, with the Zehui Aquaculture eel project receiving full support from the local government. It complied with policies to protect natural ecology and prevent water pollution. The indoor farming environment enabled water saving of 5% makeup water. The facility’s inclusion of the best possible disinfection equipment on the market ensured that the eels thrived in optimal conditions.

The systems installed:

  • 96x MR7-350PP Open Channel PP
  • 56x MR6-350PP

The systems are all sized in groups for varying flow rates, UV doses, and UV transmittance, for the treatment of glass eels, adult eels, and intake water.