Nanyang Technological University (NTU) in Singapore has developed an innovative method that uses solar energy to transform sewage sludge , a byproduct of wastewater treatment , into green hydrogen and single-cell proteins for animal feed.
A sustainable solution for recycling sewage sludge
Sewage sludge is a growing global concern. With increasing urbanization and industry, more than 100 million tons of this waste are generated each year.
Although traditional methods, such as incineration and landfill, are common, they are often inefficient and environmentally friendly. Therefore, NTU scientists have developed a solar process that integrates mechanical, chemical, and biological techniques to transform this waste into useful and sustainable products.
What is the process for transformation?
The process consists of three steps. First, the sludge is mechanically broken down, followed by a chemical treatment that removes heavy metals and other contaminants. Then, a solar- powered electrochemical process converts the organic materials into valuable products such as hydrogen, used as a clean energy source, and acetic acid, useful in various industries. Finally, light-activated bacteria convert the remaining nutrients into single-cell proteins suitable for animal feed.
In laboratory tests, the new process has proven capable of recovering 91.4% of the organic carbon from sludge , making it a much more cost-effective and environmentally friendly option than anaerobic digestion, which recovers only 50% of these materials.
A greener future
NTU researchers believe this method represents an important step toward greener and more sustainable waste management. The use of solar energy offers a clean source of hydrogen and also contributes to the circular economy, transforming sewage sludge from an environmental problem into a valuable resource for energy and food production .
However, while the results are promising, further studies are still needed to determine the feasibility of scaling this process globally. The study has been published in the scientific journal Nature Water .
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Source: Nanyang Technological University (NTU) in Singapore
Photo: Shutterstock
