A pilot "Clean Air" project for treating fine particles

Global Me@BESIX Me@SixConstruct Me@Socogetra Me@Vanhout Me@BESIX Infra Me@JacquesDelens Me@FrankiFoundations Group Me@Vandenberg Me@Cobelba 4 min read


  • Since 17 July 2019, on a pilot project basis, BESIX Clean Air panels are installed on the future N434, one of the works of the RijnlandRoute, a road infrastructure project of the Province of South Holland carried on by the COMOL5 consortium;
  • BESIX Clean Air develops panels made out of mosses. This natural material is able to treat the fine particles present in dense atmospheres in places where natural vegetation is absent (tunnels, underground car parks, industrial sites), and improve the air quality;
  • BESIX Clean Air project has been developed under BESIX’s UNLEASH! Programme, a series of initiatives to promote open innovation.

BESIX "Clean Air" panels

BESIX Clean Air develops panels made of mosses. This natural material serves to reduce the concentration of fine particles present in the air. This is a particularly appropriate method for improving air quality in dense atmospheres, such as tunnels, underground car parks or industrial sites.

Concretely, the polluted air is sucked in by fans built into the panels and blown through a membrane and a layer of moss. The air filtered by the moss is then returned to the ambient atmosphere, minus the fine particles.

The panels marry the natural qualities of the mosses with advanced technology. The panels are fitted with sensors that collect accurate data on air quality and other parameters. The use of sensors and IoT technologies also makes it possible to automate irrigation and ventilation systems, reducing maintenance costs and optimizing filtration performance.

Finally, in addition to treating fine particles in a natural way, plant mosses serve to absorb noise, make cities greener and reduce urban heat island effects.

Lennert Rasking, Engineer in the BESIX Engineering Department: "When I first submitted the Clean Air concept to BESIX's Innovation Board, my idea was to develop a product that would improve air quality in a natural way in places where nature is absent, in tunnels for example. The mosses found in our forests have all the qualities required for treating fine particles. "

BESIX Clean Air has been able to count on many partners for creating its product, both internal to the BESIX Group, such as the BESIX Water & Environment department, and external with decisive assistance coming from Innoviris (Brussels innovation agency), the University of Liège, PTS Mechelen, Achilles Design, and COMOL5. The project is subsidised by the Brussels-Capital Region Innoviris.

BESIX Clean Air

The pilot project

Since 17 July 2019, the BESIX Clean Air panels are installed on the future N434, one of the works of the RijnlandRoute, in the Netherlands. This is a road infrastructure project being undertaken by the COMOL5 consortium (Vinci Construction Grands Projets S.A.S., TBI Holdings b.v. and DEME Infra Marine Contractors B.V.), for the Province of South Holland.

For COMOL5, its first customer, BESIX Clean Air has installed 45 m² of panels along a site service road used in particular by trucks delivering materials for the construction of a new tunnel.

Lennert Rasking, Engineer in the BESIX Engineering Department: "This is an important step for BESIX Clean Air. This on-site installation will serve to validate our already more than conclusive theoretical results, and to measure more precisely the technical performance of the panels. We should be able to start some initial analysis by early autumn. Our ambition with this first project is to reduce the concentration of fine particles by at least 20%. "
BESIX Clean Air Panels on the N434

The Unleash! programme

The Clean Air project has been developed as part of BESIX’s UNLEASH! Programme, a series of initiatives in the area of Open Innovation. These include an Innovation Competition, where all BESIX employees have the opportunity to present innovative ideas. Recent years' prizewinners include BESIX Clean Air and BESIX 3D, a 3D concrete printing unit.

UNLEASH! also offers innovation-focused workshops, Smart Hackathons and Bootcamps, as well as a start-up accelerator. The Accelerator is a programme open to mature start-ups around the world which are developing products or services in construction and/or real estate technologies ("ConTech" and "PropTech").

Patrik Peynsaert, BESIX Innovation Coordinator: "BESIX Clean Air is a wonderful example of BESIX's policies in the area of open innovation. The Group's objective here is to gain maximum exposure to new ideas, which can transform and improve our traditional sectors of activity. BESIX Clean Air also perfectly embodies BESIX's mission and the heart of its strategy: Excelling in creating sustainable solutions for a better world."


Based in Brussels, Belgium, BESIX Group operates in 25 countries and on 5 continents, primarily in the construction, real estate development and concessions sectors. Iconic projects include Dubai's Burj Khalifa, the world's tallest tower, various European Parliament buildings in Brussels and the Grand Egyptian Museum, on the Giza Pyramid Plateau.

BESIX carries out major environmental projects. Ongoing works include an energy-neutral tunnel in the Netherlands, a world first, as well as sustainable water treatment and waste recycling facilities in the European Union and the Middle East.

For further information: www.besix.com