Researchers from the Vrije Universiteit Brussel and the Université Libre de Bruxelles (ulb to go for a recycling process to be developed, raw materials such as gold and silver contained in the sludge in the Brussels sewer system to be filtered. With their new project, ” Sublimus’, they want to look at the recyclagepotentieel of the existing carry forward of unused waste.

The primary raw materials are becoming more and more scarce, and it is estimated that within 20 years, metals such as lead, tin, zinc, gold and silver will be exhausted. Because of the recycling of metal is also important to the researchers to be a cheap and green way to precious metals is to harvest the sludge from the wastewater treatment plants.

The metals are frequently found in the sludge, through, for example, jewelry, or prescription drugs, and pesticides. Previously, the sludge was used as fertilizer for agricultural use, among others, due to the high metaalconcentraties this practice is now banned in the region.

The Submimus project is a three-stage work. The first tests are performed in order to determine how much of the precious and heavy metals from the sludge sitting there. In a second step, it is investigated how this metal in an environmentally friendly way, out of the mud, may be extracted by, for example, the use of specific bacteria to the metals contained in the sludge is “washed”. The third step is to find an eco-friendly way to create the alloy, to purify, and recycle. An example of this is the development of a specific magnet, that is, the precious metals contained in the sludge filter. The research carried out by the Sublimus project will continue until the end of February, 2022.