Frequently Asked Questions


Frequently Asked Questions

The Great Bubble Barrier

How does a Bubble Barrier work?
The idea is simple. A tube with holes is placed on the bottom of a river. Pumping air through the tube creates a bubble barrier, or air curtain. The air bubbles force plastics in the water to the surface, making them accessible for removal. This concept is used in the oil industry, the dredging industry and in the Dutch lock system. By placing the bubble barrier diagonally to the flow of a river, the power of the river forces debris to the banks of the river, where it can be easily removed from the water.
Is The Great Bubble Barrier the solution to all the plastic soup in the world?
The Great Bubble Barrier was developed to help address the plastic problem. Our solution aims to achieve a more sustainable environment and the protection of ecology. The solutions to the plastic problem are broadly divided into five different categories:

  • Create awareness among manufacturers (of products, foodstuffs, etc.) to make sure that less plastic is used wherever possible. Manufacturers can choose other materials, or plastic types that are recyclable.
  • Creating awareness among consumers to ensure that they choose products with less environmental impact, for recyclable plastics, and collecting and separating plastic waste.
  • A well-designed system for processing plastic waste based on quality. Fortunately in the Netherlands we have a highly technical waste system..
  • Preventing dumping of plastic waste in the sea (responsible for 20% of the plastic soup)
  • Stopping the flow of plastic waste from inland via the rivers and canals to the sea (responsible for 80% of the plastic soup)

The Great Bubble Barrier is not the only solution to solve the plastic waste, as we focus primarily on plastic soup in rivers. In addition, The Great Bubble Barrier, along with organizations such as the Plastic Soup Foundation and ByTheOceanWeUnite, builds awareness among consumers, producers and governments alike. The remaining 20% of the plastic soup in our oceans is created on the ocean, and is thus out of reach of our Bubble Barriers. We gladly accept this gigantic task from The Ocean Cleanup. In politics and business, many steps can be taken to prevent plastic soup. The end responsibility for waste that ends up in the water is still a gray area in the Netherlands.

Is there a Bubble Barrier in use?
At the moment, there are no permanent Bubble Barriers. However, a pilot has been conducted in Deltares’ test environment. Also, our colleague Philip Ehrhorn, has conducted a pilot in a side channel of the Berliner Nordgraben in Germany. Last November, we have tested a Bubble Barrier of 200m in cooperation with Rijkswaterstaat, Deltares and BAM/van den Herik in the IJssel during three weeks.
How is the plastic collected?
During the pilot in the IJssel we will collect the plastic with nets and manually bring it ashore. This technique is possible because the Bubble Barrier flows into an inlet. This way, we can make the most of the surrounding environment and natural conditions of the IJssel. In subsequent projects, we will constantly investigate what is the best collection method for that particular location, and install as many automatic collection systems as possible.


How much plastic does a Bubble Barrier remove?
Based on the results of the pilot at Deltares research institute, it has been calculated that the Great Bubble Barrier captures approximately 70-80% of  top-surface floating plastic and 50% of plastic underwater.

During the tests in the IJssel we will look at how these results translate in a river. The results depend on different conditions, such as how long the underwater tubing is, or if it has recently rained, the type of plastic in the river and of course the location of the Bubble Barrier.

Does a Bubble Barrier also work against microplastics?

During the Berlin Bubble Barrier Pilot, the Bubble Barrier was able to catch plastic as small as 1 millimetre. It depends on the collection system whether the smaller plastics are able to be brought ashore. We will continue to develop our removal system following the pilot in the IJssel. The goal is to remove also remove microplastics from the water.

Are all types of plastic caught by the Bubble Barrier?
This will be further investigated during the pilot in the IJssel. During the tests at Deltares, different types of plastics were tested: from packages, water bottles, popped balloons, plastic bags, bottle caps and plastic grit. Most floating plastics and underwater plastics could be caught. Unfortunately, plastic that has sunk and rolls slowly over the bottom of a river is unlikely to be able to be caught.


What is a Bubble Barrier made of?
The Bubble Barrier is a rubber tube with holes in it. This tube is reinforced with a steel cable, and is attached to the bottom at some points with steel or (recycled) concrete blocks.

Plastic Extraction & Use

What happens to the collected trash?
We collect the plastic of the pilot for research. However, we are always looking for creative uses for the plastic which has been removed, in order to create more awareness about this problem.

Furthermore, we will separate all the remaining waste for processing by the Kampen municipality.

Energy consumption

How much energy does it cost to pump air?
The Bubble Barrier uses compressed air to create the bubble curtain. Depending on the scale and length of the Bubble Barrier, this is done by means of a blower or compressor. The length of the bubble barrier has such a significant influence on the necessary energy usage. Because the Bubble Barrier does not need to create water column, like in a separation of a fresh/saltwater barrier, much less energy is required for the Bubble Barrier than with a bubble curtain in locks.
What is this in relation to?
Depending on the size of the bubble curtain, the energy consumption is comparable to that of five boilers (in the case of the IJssel pilot) to that of a pumping station.


How did The Great Bubble Barrier come about?
The idea for the Bubble Barrier was created by Saskia, Francis and Anne Marieke in early 2015, based off their long-time frustrations about all the waste pollution they saw in the water. All three experienced sailors, they saw a lack of initiatives to stop this waste pollution which had a direct impact on their sailing. This frustration created the idea of ​​a bubble curtain, a barrier. Research showed that although bubble curtains were used to stop salt and fresh water from mixing, sand, noise pollution and oil spillage, they were not yet used for plastic. The Plastic Free Rivers Makathon of Rijkswaterstaat and PWN in January 2016, proved to be the perfect opportunity to submit the idea to the Dutch water authorities. A lot has happened since this first Makathon. The Great Bubble Barrier has quickly grown to become a social enterprise with a team of 8 people, with a successful pilot at Deltares, growing relationships with our partners and suppliers, and even more innovation awards, prizes and subsidies.


I have suggestions and/or feedback, can I contact you?
Of course! We will happily receive any questions, suggestions or feedback you may have. You can leave a message via the contact form and we will contact you as soon as possible.
Can I become a volunteer at The Great Bubble Barrier?
We are always looking for helping hands. Feel free to get in touch.
How can I do an internship, research placement or graduation project at The Great Bubble barrier?

At the moment, we are looking for students who can assist us in marketing communications. Please send us a message with our contact form. 

Support, Funding & Donations

How can I donate?

Check out our funding page to see how you can contribute!

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