Frequently Asked Questions

Frequently Asked Questions


Bubble Barrier Technology

How does the Bubble Barrier work?

We create a bubble curtain by pumping air through a perforated tube on the bottom of the waterway. The bubble curtain creates an upward current which directs plastic to the surface. By placing the Bubble Barrier diagonally across the river, the natural flow of the water will push the plastic waste to the side and into the catchment system. The catchment system is designed to work in harmony with the bubble curtain to collect and retain plastics. Following collection, it will be removed for processing and reuse.

Bubble curtains have been around for a long time. They are widely used in the oil and dredging industry, as well as in the Dutch lock system. The Bubble Barrier system, created by The Great Bubble Barrier, is the first bubble curtain used to capture plastic pollution.

Which Bubble Barriers are currently in use?

There are several active Bubble Barriers capturing plastic pollution across the globe. You can find all Bubble Barrier projects on our Projects page. 

How is the plastic pollution collected?

Once plastic pollution encounters the Bubble Barrier, it is guided to the side of the waterway, where it's collected in the catchment system. The catchment system is tailored to work with the existing infrastructure of the specific location. Depending on the Bubble Barrier location, the catchment system will then be emptied from water or land. 

Does the Bubble Barrier allow fish to pass?

Bubble Barriers are safe for fish migration. Most species will pass through the bubbles or take a short time before they pass it. We nevertheless implement a fish passage in each design under the catchment system. With every new project, the local ecological impact of a Bubble Barrier is carefully considered in collaboration with ecologists. 

Whales use bubble-net feeding to hunt fish. Does the Bubble Barrier have the same effect on fish?

Humpback whales use the so-called "bubble-net feeding" method to concentrate herring near the water surface. Whales use air bubbles to blow a ring around the school of fish before they jointly breach the surface and feed on the fish. Research suggests that the main driver behind the concentration of the fish is the sound that the whales make when they blow the bubble ring. The bubbles will create a “wall of sound” which scares the fish away from it rather than being afraid of the bubbles themselves. The Bubble Barrier technology is thin and silent, using tiny bubbles, which don't come as a surprise to passing fish. 

Can the Bubble Barrier be used for something other than plastic capture?

Bubble curtains can also be used for other applications than the capture of plastic. However, the Bubble Barrier system focuses on the capture of plastic pollution in waterways. For all other bubble curtain applications, we would like to put you in touch with one of our partners.



How much plastic waste of which sizes can a Bubble Barrier remove?

Bubble Barriers have a catch rate of 86% of the floating plastic pollution in a waterway. The technology effectively catches plastics from 1 mm to 1 m in size. 

Can the Bubble Barrier capture microplastics?

Bubble Barriers can capture microplastics from 1 millimetre.
Bubble Barrier Wervershoof was placed in a wastewater treatment plant as part of a research alliance to research the effectivity of the bubble curtain on microplastics smaller than 0.5 millimetres. Additional research is needed to test the Bubble Barrier's efficacy on smaller microplastics. 

Which types of plastic are captured by the Bubble Barrier?

At Deltares, various types of plastics were tested during the pilot tests, including packages, water bottles, popped balloons, plastic bags, bottle caps, and plastic grit. The Bubble Barrier was able to capture most floating plastics and underwater plastics. However, it is unfortunate that plastic that has sunk and rolls slowly over the bottom of a waterway is unlikely to be captured.


What is a Bubble Barrier made of?

The Bubble Barrier creates a bubble curtain with a perforated tube placed on the bottom of the waterway. The tube is made of EPDM and reinforced with an anchoring system upon implementation in the waterway. 

Plastic Extraction & Use

What happens to the collected (plastic) waste?

Plastic caught by our Bubble Barriers is collected by the local Water Authority who in turn send it to a recycling centre. Wherever we implement a Bubble Barrier we help to ensure the waste is processed most sustainably through existing waste management systems.

For most Bubble Barrier projects, the plastic waste is sorted and monitored for a certain period to collect impact data. The types, sizes and sources of (plastic) waste are researched in these monitoring programmes. Valuable insights and data, resulting from the monitoring, can be used to strengthen the urgency to act and advocate for policy change to tackle plastic pollution in waterways. The Great Bubble Barrier and our partners use the OSPAR-river method when monitoring waste captured by Bubble Barriers. The OSPAR-river method is a riverbank litter monitoring protocol that offers a practical and standardised framework, sporting over 100 individual waste categories. 

We are currently exploring with partners to recycle the collected plastics. However, as a tech scale-up, we focus on the efficacy and deployment of the Bubble Barrier technology and its catchment system. Other great innovative companies focus on sorting, identification, and recycling of river plastic only.

Energy Consumption

How much energy does a Bubble Barrier use?

The Bubble Barrier uses compressed air, pushed through a tube, to create the bubble curtain. The width of the waterway, and thus the length of the bubble curtain tube significantly influences the necessary energy usage.

The first Bubble Barrier in Amsterdam has about the equivalent energy use of an electric street sweeper in The Netherlands. As each waterway and city has their own specificity, the energy needed to power the Bubble Barrier system varies. Wherever possible, we try to power our Bubble Barrier with renewable energy.

We currently prioritise cleaning our streets over our waterways, mainly due to the lack of regulations and budgets to clean rivers. We must continue advocating for clean freshwater systems, as they are vital in sustaining livelihood on earth. 

Strategy & Team

What is the mission of The Great Bubble Barrier?

The Great Bubble Barrier aims to remove as much plastic pollution as possible from waterways using Bubble Barriers.
Besides cleaning rivers from plastic, we:

  • Monitor the amount of plastic in waterways to ignite policy change
  • Increase awareness of plastic pollution
  • Ensure sustainable processing of the catch
Are there career opportunities at The Great Bubble Barrier?

The Great Bubble Barrier is a young and fast-growing Dutch scale-up based in Amsterdam, the Netherlands. To get the rivers free from plastics, we’re always looking for talented and motivated pioneers to join our mission. View all career opportunities here.

Are there volunteering opportunities at The Great Bubble Barrier?

At The Great Bubble Barrier, we are always looking for helping hands. Get in touch with us to discuss possibilities. We might acquire your CV.

Are there internship opportunities at The Great Bubble Barrier?

We would love to work with you. All the available internships are listed on our careers page.

Support, Funding & Donations

How can I support your mission and donate?

Thanks for your interest in supporting our bubbly mission. Check out our donation page to see how you can contribute!


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 visit a Bubble Barrier?

Yes, you can visit Bubble Barrier Amsterdam in the Westerdok, both virtually and physically.