Stradal launches DDSelect, a rainwater pollution treatment solution

More efficient, the DDSelect meets all the needs and constraints of communities in the fight against urban pollution.

Hydrodynamic settling: a major innovation

In 2019, Stradal joined forces with Hydro International, a world specialist in pollution treatment, to design and manufacture First Defense, the first water pollution treatment solution by hydrodynamic settling, integrated into a high-performance concrete envelope.

Today, with 3 years in the field and feedback from the installation of more than 200 hydrodynamic decanters in France, Stradal has designed a new generation of decanters, the DDSelect.

This innovative hydrodynamic settler targets Suspended Solids (SS) thanks to a settling system that treats particles with a median size of 63 μm, with a reduction of more than 80% of SS and their associated pollutants.

It is available in a range comprising 12 products: 6 sizes and two levels of performance to meet the needs of local authorities as closely as possible.

Low-carbon concrete: a high-performance and more ecological material

The DDSelect is integrated into a high-performance low-carbon concrete envelope which allows a 30% reduction in the ecological footprint compared to conventional concrete. It ensures a perfect seal and withstands stresses throughout its lifespan estimated at more than 50 years.

In addition, it is 100% recyclable, and comes from a local industry and local materials.

Ultra-compact and precisely sized, the DDSelect hydrodynamic decanter has an extremely small footprint. It is a tailor-made structure, customizable on demand: angle, diameter, materials, height... It is thus 10 times less bulky than a lamellar settling tank and 30 times less than a settling tank. The DDSelect can be installed on an existing network, making it possible to limit works, investments and enhance the heritage.

More than a hundred DDSelect decanters already in operation

With treatment volumes of up to 1.400 liters of water per second, the DDSelect can handle projects of any size anywhere in France. About twenty references have already been installed in the Eurometropolis of Strasbourg. Projects are underway in many communities such as Arcachon and on the coast where the challenge in terms of water treatment and quality in connection with human activity is particularly high.

Hydrodynamic settling to target all pollution

To treat the pollutants present in rainwater, one of the most effective solutions2 is hydrodynamic settling. It combines two forces: gravity and centrifugal force and is based on the vortex effect separation process: a liquid/solid separation process that allows retention of the finest mineral or organic particles.

This technology makes it possible to treat both suspended solids (SS) and their associated micropollutants as well as macro-waste (cigarettes, cans, plastic packaging, etc.).