Research published in 2021 in Science Advances carried out by the non-profit organization The Ocean Cleanup shows that 80% of all plastic in the oceans comes from rivers and that, contrary to popular belief, most plastic reaches the sea via many small and medium-sized rivers.
The Our World in Data portal has transformed the data from the research into graphs to make it easier to understand. As seen in the table below, early studies (grey and blue line) indicated that few rivers are linked to pollution. In contrast, more recent research (red line) shows the opposite that 1656 rivers are responsible for discharging 80% of plastic into the oceans.
For example, the most polluted river in the world is the 270 km long Citarum, which flows in Java, Indonesia’s most populated island. Its contamination level is five thousand times higher than the permitted level, which leads to the death of about 50,000 people every year. However, Citarum does not appear among the 10 rivers that most pollute the sea with plastic waste.
As shown on the map, the first one is the Pasig River in the Philippines, which flows through the country’s capital Manila, where 14 million people live. Just over 9 km long, it is said to be one of the most plastic-polluted rivers in the world. Next are Klang (Malaysia), Ulhas (India), Tullahan (Philippines), Meycauayan (Philippines), Pampanga (Philippines), Libmanan (Philippines), Ganges (India), Rio Grande de Mindanao (Philippines) and Agno (Philippines).
Plastic pollution in the oceans causes enormous damage to marine life. According to the WWF report entitled “Plastic Pollution in the Oceans. Impacts on species, biodiversity and marine ecosystems” published in February this year, more than two thousand marine species have come into contact with plastic. Up to 90% of all seabirds and 52% of all sea turtles ingest plastic.
Several factors cause the death of marine animals: entrapment, ingestion, suffocation, and the release of toxic chemicals. When ingested, plastic nanoparticles reach brain tissue, causing neurotoxicity in the animals.
The report also highlights the food chain by showing how plastic ingested by marine animals reaches our plates. According to the report, 59% of bony fish found in the Mediterranean have ingested plastic and many species end up on our tables, such as sardines, mullet, anchovies, and tuna.
The situation will be irreversible if the ocean’s level of plastic pollution does not slow within a few years. Until governments find a sound international agreement on plastic lifecycle standards, individuals and companies have started to think of practical solutions to solve the problem at its root, i.e., collect waste from freshwater streams before it flows into the oceans.
This is what River Cleaning Plastic & Oil does, a river cleaning technology devised by Italian Vanni Covolo, CEO of Mold S.r.l, a Vicenza-based company operating in the thermoplastic materials sector. With its floating buoys made of recycled polypropylene and arranged horizontally to take advantage of the water current to function, the eco-sustainable project, patented in 2019, literally intercepts debris in river waters.
River Cleaning technology not only operates 24 hours a day, requires little maintenance and energy, has zero impact on the environment, and does not disturb river fauna and flora. The system allows navigability, is adaptable to any waterway, and manages to intercept 85% of floating rubbish.
In January 2022, River Cleaning introduced a system version named V4.22. What is new, however, are not inconsiderable advantages, including meager installation costs and low maintenance requirements, thanks to the structure being located entirely out of the water. Last but not least, there is now the concrete possibility of using the rotation of the buoys to generate electricity and extract it easily – thus powering the automatic parts of the system that will allow self-cleaning, opening as boats pass by, or simply feeding it into the power grid.
The system is innovative, and the project has such enormous potential that last January, it received the Friend of the Sea sustainability certification, an environmental and humanitarian conservation organization.
In addition to plastic, River Cleaning has also devised a technology to recover oils and other polluting liquids spilled into rivers. The system is divided into two versions: the simpler one works thanks to the principle of absorbent sponges and can deal with the problem in small watercourses. The more sophisticated one – designed for large spills and useful in the event of an accident at sea – consists of a centralized mechanical suction and filtering system that allows large volumes of water to be regenerated, radically reducing the count.
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