Plastic is ubiquitous, not only in every household, car, and piece of clothing but also increasingly in the environment. It is estimated that 11 million tons of plastic waste enter the oceans from rivers each year. This poses a significant problem as marine organisms ingest plastic particles, accumulating them in their bodies. Humans are also affected, as calculations suggest that we consume an average of 5 grams of microplastics per week, equivalent to about one credit card.
Rivers play a crucial role in distributing this plastic. About 80 percent of the total plastic input into the oceans comes from approximately 1,600 rivers, primarily in Southeast Asia and parts of South America and Africa. Once in the oceans, plastic spreads worldwide, even reaching the Arctic and Antarctic regions in the form of tiny plastic particles.
In Switzerland, the problem is somewhat less acute but still of significant concern. According to a study by Empa in 2019, around 5,000 tons of plastic end up in the environment in Switzerland each year, with 115 tons reaching water bodies. Littering (recklessly discarding waste) is a major contributor, along with construction sites and traffic (tire abrasion). The issue has also affected Lake Lucerne, prompting attention from the public, authorities, and wastewater treatment facilities.
To prevent plastic from entering the world's oceans and the widespread distribution of small plastic particles throughout the environment, innovative solutions are needed. Besides addressing emission sources, there is a particular focus on rivers as a crucial area of concern.
of plastic end up in the environment in Switzerland each year
The Autonomous River Cleanup (ARC) project is an initiative launched by students at ETH Zurich in November 2019. Its objective is to utilize ETH technology (robotics, artificial intelligence, material sciences, and hydrology) to combat plastic pollution in water bodies.
The team, composed of bachelor's and master's students, doctoral candidates, postdoctoral researchers, and ETH professors, is developing a system called the Autonomous River Cleanup platform. This platform is designed to autonomously capture, analyse, and sort waste from water bodies, primarily rivers. It also identifies organic materials and returns them to the water immediately.
« [...] the ARC platform is more sophisticated as it incorporates additional, highly advanced technology for analyzing and robotically sorting the collected waste. »
The special aspect of this project is the exploration and application of high technology from ETH Zurich in a very real context. Other existing river cleanup platforms, such as the Interceptor from the Ocean Cleanup project or the system from RiverRecycle, extract all material particles from the river, regardless of their type. In contrast, the ARC platform is more sophisticated as it incorporates additional, highly advanced technology for analyzing and robotically sorting the collected waste.
The analysis ensures that the intervention in nature is "minimally invasive" since only environmentally harmful materials are extracted from the water bodies. The robotic sorting, on the other hand, ensures that the materials are separated into different categories and can be properly and appropriately disposed of or reused.
While ARC's technology can be combined with other platforms to add value, it stands out for its refined approach and advanced capabilities in addressing river pollution. Currently tested in Zürich, the project aims at being deployed worldwide.