Can Bubbles Clean Rivers?

The problem of plastics polluting the planet’s rivers and oceans is well known. The use of plastics, particularly single use plastics, has been reduced in recent years, but plastic materials are still finding their way into the water.  Plastic waste that reaches a river or canal is likely, eventually, to flow into the ocean. Once plastic waste reaches the ocean, the challenges of locating and removing it increase significantly.

One company, The Great Bubble Barrier, believes that it has found a solution which uses bubbles to create a barrier across a watercourse preventing plastics from passing and reaching the ocean and, in 2019, it filed a patent application to protect its solution.

The idea of using a bubbles to create a barrier or curtain has been around for many years.  Over the years these bubble curtains, or pneumatic barriers, have been used to protect against salt water intrusion into rivers, to contain oil spills or construction sediment, and to minimise the adverse effects of construction noise on aquatic life.  A side-effect of using bubble curtains is that they can oxygenate the water, and this may be an advantage in some applications.

Bubble barriers have significant advantages over other barrier technologies.  They are simple to construct, requiring only a perforated pipe and an air compressor, and they do not prevent the movement of boats or fish in the same way as a physical structure.

To create a bubble barrier a perforated pipe is arranged underwater, typically anchored so that it cannot move, and air is pumped into the pipe.  The air escapes from the perforations to create bubbles which rise to the water surface.  The rising bubbles create a rising current which acts as the barrier.  By appropriately selecting the positioning and density of the perforations, and the volume of air being pumped into the pipe, a substantially continuous curtain of rising bubbles and water can be created which can move material to the surface.

Since bubbles-as-a-barrier technology is known, The Great Bubble Barrier could not seek protection for the concept itself, but it has filed a patent application focussed on the implementation of that technology in a watercourse.

The patent claim requires that a bubble screen is installed at an angle to the water flow and that the downstream part includes a collection area.  The claim also requires that a bubble intensity of the downstream part of the bubble screen is less than the bubble intensity elsewhere in the bubble screen.  These features are described in the specification as combining to guide the plastic to the collection area and to reduce eddy formation which might otherwise hinder the guiding action.

Bubble barrier across a watercourse preventing plastics from passing and reaching the ocean

There are a number of other features disclosed in the patent specification that might be beneficial, for example having the bubble barrier curved convexly towards the collection area.

The system developed by The Great Bubble Barrier uses a bubble curtain together with a catchment system in the collection area.  The catchment system described in the application may comprise a meshed wall to sieve out the plastics guided to the collection area to allow the plastics to be collected and removed, while the water passes through the screen.

An example of the system has been successfully operating in Amsterdam for some time, helping to prevent plastic pollution passing from some of Amsterdam’s canals into the North Sea.

The patent protection applied for could, if granted, be used to prevent third party use of the technology, but a patent does not have be used in this way.  A patent is a commercial tool providing the patentee with a degree of control over the patented technology.  That control can help the patentee to secure a return on the R&D investment needed to create the invention, and there are many ways to achieve this return.  As mentioned above, one way is to prevent third party access to a technology and maintain an exclusive position.  Another way is to charge third parties a licence fee to work the patented technology.  Licences can work well for both parties, the licensor receives a return on its investment without having to work the invention, while the licensee may obtain access to information not in the patent disclosure, such as the patentee’s know-how and other internal materials.

In this case, the environmental nature of the invention, and the green vision of the company, may mean that, if the patentee cannot, or does not wish to, install a bubble barrier in a particular location, licences would be available on reasonable terms to those that will.

If you have any questions about IP protection for your own products, or about the IP protection of others, please do not hesitate to contact us at to see how we can help.

Category: News | Author: Alex Bone | Published: | Read more