Dutch start-up The Great Bubble Barrier developed technology to capture floating (micro) plastic from rivers, using a curtain of bubbles.

The Bubble Barrier is made by pumping bubbles through a perforated tube at the bottom of a waterway, such as a river or canal. The bubbles form an upward current that redirects plastic to the surface.

The system consists of three main components. The first is the tube at the bottom of the waterway that creates the bubble curtain. The location and necessary airflow are adapted according to the flow dynamics of the waterway. The hose is made of rubber tubing.

The bubble curtain is created by using compressed ambient air, generated by electric compressors. These are powered by renewable energy if possible.

Finally, the bubble curtain is paired with a catchment system. 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. There, it can be collected for recycling or reuse. The system captures plastic particles as small as 1 mm and intercepts 86% of floating material.

The Bubble Barrier has several advantages. It can operate 24/7 with no need for operators, and it functions over the entire width and depth of the river. It is suitable for various types of waterways, from narrow canals to tidal rivers. Moreover, the bubbles capture only plastic, so fish and boats are not obstructed. In addition, the extra oxygen in the water prevents algae growth at the surface and benefits aquatic life.

There are currently Bubble Barriers in the Porto region in Portugal and in Amsterdam and Katwijk in the Netherlands.

Images: The Great Bubble Barrier