Black Soldier Fly-based bioconversion of biosolids creates high-value products with low heavy metal concentrations

Annually, over 30 million dry tonnes of biosolids are produced worldwide, most which disposed into landfills or discharged waterbodies, exacerbating eutrophication and water-borne diseases. Bioconversion using Black Soldier Fly larvae (BSFL) can produce high-value biomass (protein, lipids, chitin) while reducing the volume waste that requires disposal. We aimed to determine bioconversion performance BSFL on different types blends analysed bioaccumulation heavy metals in larvae. converted all substrates similar protein content (31–37%). However, growth substrate reduction were significantly lower for unblended compared wheat bran. Blending with other organic such as food bran improved (< 40% after 20 days; < 149 kg larvae/ tonne substrate) fat 31%). Despite initial high concentrations 8700 mg/ kg), largely partitioned residues instead mature BSFL, resulting low those elements 180 kg). These even below limits international guidelines animal feed. Therefore, this study demonstrated BSF-based be an innovative sustainable management resource recovery technology rapidly reduce volumes transforming it metal concentrations.