Scientists at Nanyang Technological University (NTU) in Singapore have made a groundbreaking discovery by developing a solar-powered process that transforms sewage sludge—an environmental burden—into valuable products: green hydrogen and single-cell protein. Sewage sludge, typically a by-product of wastewater treatment, is often discarded or incinerated, contributing to pollution. In this new method, the sludge is first broken down mechanically, then chemically treated to separate harmful heavy metals and other contaminants. The final step involves using solar-powered electrochemical reactions to convert the remaining organic materials into acetic acid and hydrogen gas. The resulting green hydrogen can be used as a clean energy source, while the single-cell protein, derived from the organic carbon in the sludge, serves as a nutritious animal feed.
This innovative technology could transform waste management and energy production on a global scale. The process recovers more than 91% of the organic carbon in sewage sludge, turning 63% of it into single-cell protein, a highly efficient and sustainable protein source. Moreover, it reduces CO₂ emissions by up to 99.5% compared to conventional methods of sludge disposal. With the increasing volume of sewage sludge in growing urban populations, this approach presents a dual solution—reducing environmental pollution while generating renewable energy and nutritious protein. The technology not only supports a circular economy but also offers an eco-friendly alternative to the traditional disposal of wastewater by-products, making it a promising step toward achieving sustainable food and energy systems. More