80% of the waste found in the sea comes from the land and 10 million tons of waste are discharged into the sea each year worldwide.
As soon as there is heavy rainfall, coastal cities discharge waste, plastics and other pollutants directly into the sea via rainwater outlets, both on land and underwater, like a real flush.
The French start-up Green City Organisation has created a patented device called
"D-Rain".
The "D-RAIN" system is a real-time connected solution to capture waste at a land or underwater outlet before discharge into the sea.
This waste collection net has been installed at the outlet of one of the stormwater networks of the Old Port of Marseille.
The installation will serve as both a test and a demonstrator for the next 18 months.
It consists of three nets mounted in parallel, hung on a 4 x 3 meters structure.
Each net is made of two nets one inside the other.
One small mesh inside, to trap waste up to 5 mm, like a cigarette butt. The other, a larger one, solidifies the whole.
The system is equipped with a smart and connected collar that is attached to the outlet and the nets.
This is a real innovation because the flange can pivot upwards to open and let the water flow through when the net is full and the pressure is too high. This automatic device eliminates the need for operators to be on site. When it is opened, it sends a telephone alert.
* The installation and emptying times of the nets are optimized, adapted to the local collection equipment.
The system will also allow the startup to complete the development of its next innovation: the insertion of capsules in the nets capable of capturing pollutants dissolved in the water such as hydrocarbons, heavy metals or drug residues.
While waiting for the results of this full-scale test in Marseille, the start-up is in discussions with other cities to install its system, including Morocco and Tunisia.
In August 2018, Australia had also created a similar system in a nature reserve in Kwinana, installing waste collection nets on a trial basis, reducing discharges from drainage systems.
"We are often told that there are already nets on outfalls. This is true, but our solution is the only one of its kind, connected and monitored in real time. It also provides information on the phytochemical characteristics of the water: temperature, acidity, turbidity..." says Isabelle Gerente, president and founder of Green City Organisation.