The black river explained. It happens only in one place in the world

Scientists from the Federal Institute of Technology in Zurich have examined the composition of the water in the darkest river in the world. They managed to discover what is the reason for such a dark color.

The Ruki River, flowing through the Democratic Republic of Congo, is considered the darkest river in the world. A tributary of the Congo River is even darker than the famous Rio Negro, which in turn is the longest left tributary of the Amazon. Larger cities located on the Ruki include Mbandaka and Boende.

Many years ago, scientists from a prestigious Swiss university were intrigued by the extremely dark color of the water in the Ruki River and decided to take a closer look. Since the 1930s, research on the state of the water has been ongoing.

It wasn't until recently that scientists decided to expand their research to analyze the chemical composition of water. In 2019, an international team of scientists set up a measuring station in Mbandaka, just before the confluence of the Ruki and Congo rivers. For a year, every two weeks they meticulously analyzed the water composition. Their research allowed them to draw interesting conclusions.

Ruki is mostly surrounded by virgin rainforests and peatlands. Scientists have discovered that the river has a high concentration of dissolved carbon in its waters, which explains its black color. The carbon enters the waters of Ruki from the surrounding forest. Organic material found on land is poured into the river during heavy rains.

Interestingly, the Ruki River has a four times higher concentration of carbon than the Congo, into which it flows.

The hands are also characterized by a low level of tilt and a small amount of remaining residue.