clean up rainwater at Toulouse-Francazal airport
Toulouse-Francazal airport is equipped with the aquatextile called “GeoClean”, manufactured by the French company TenCate Aquavia. The latter makes it possible to filter the hydrocarbons that escape from vehicles or planes and mix with the rainwater, before it flows into the environment.
A large blue textile that filters hydrocarbons mixed with rainwater before it flows into nature. Here is the image that we can give to theGeoClean aquatextiledeveloped for ten years by the French company TenCate Aquavia. This equipment has just been installed on the new northern extension of Toulouse-Francazal airportin Cugnaux.
5,400 square meters to filter rainwater
The GeoClean aquatextile has been deposited at the bottom of a basin of 5,400 meters, dug few square deep in the ground, bordering Toulouse Francazal airport. Then it was covered with twenty centimeters of earth.
The goal of this solution is to filter the rainwater that pours onto the new 90,000 square meter tarmac, recently integrated into the northern part of the airport. “Since its surface is impermeable, the rainwater will run off to the drains. Then it is transported by pipes which reach the basin where GeoClean is installed”, explains Thomas Bailet, business engineer at TenCate AquaVia. According to company estimates, the amount of hydrocarbons brought by storm runoff from this part of the airport is estimated to 100 liters per year.
How it works ?
The aquatextile is made up of two layers of fabric. The first, blue, allows you to fix hydrocarbons present in mass in runoff water after a rain event above an activity or parking area. These hydrocarbons can be petrol, diesel, kerosene… But also engine oil.
The first layer of the Geoclean aquatextile is impregnated with microorganisms. “We proceeded to provide a sort of five-star hotel, with humidity, heat, oxygen and food so that they can develop more easily”, specifies Thomas Bailet. Those small bacteria, or mushrooms, take care of ingesting and then biodegrading the hydrocarbons. They are subsequently released as CO2 and water.
Some molecules can take several weeks to be biodegraded, hence the importance of the aquatexile fixing the hydrocarbonsto give the microorganisms time to do their job.
The second layer, white, simply reinforces the filtration in the event of an accidental and substantial spill of hydrocarbons.
Reproduce the natural pattern of water
This aquatextile makes it possible to filter rainwater at the source, before it flows into nature. The objective is to do not alter the natural water cycle. No more need to use traditional rainwater drainage networks, which are already saturated and often less effective against pollution. “In general, the hydrocarbons collected by the sewerage networks can be, in part, retained by pre-treatment devices (decanters or separators). But these retain only a fraction of the pollution. In addition, rainwater networks or combined networks (mixture of wastewater and rainwater) have limited evacuation capacities, which leads to the use of storm overflows more and more frequently during heavy rains, and reject the pollution to the receiving environment. This is why we now turn to integrated and sustainable stormwater managementwhich is based on the depollution of rainwater during its infiltration into the ground, at the source of the runoff”, explains Thomas Bailet.
By passing through GeoClean’s filtration, the water that has reached groundwater is cleared “over 99%”believes the engineer, and therefore preserves soil biodiversity.
A solution made in France
GeoClean is designed and manufactured in France, in the town of Bezons (Val-d’Oise), on the border with Paris. This aquatextile requires no maintenance. “It is autonomous and durable”, notes Thomas Bailet, stating that GeoClean has a service life over 50 years.
Launched four years ago, the solution has been installed in more than 200 locations in France and Europe. “We have also carried out many projects around Toulouse, which is a very buoyant sector. A first phase of work has also been initiated in the Portet-sur-Garonne decathlon car parkfor example”, concludes the engineer.