Evaluating the Microbial Safety of Heat-Treated Fecal Sludge for Black Soldier Fly Larvae Production in South Africa

Incorporation of black soldier fly larvae (BSFL) in fecal sludge management shows promise as a resource recovery strategy. BSFL efficiently convert organic waste into valuable lipids and protein, which can be further processed commercial products. Ensuring the microbial safety waste-derived products is critical to success resource-oriented sanitation requires development effective treatment. This study evaluates treatment efficacy viscous heater (VH) for potential application VH production. The heat-based technology that harnesses viscosity achieve pasteurization temperatures. Inactivation situ Escherichia coli, total coliform, heterotrophic bacteria, somatic coliphage was evaluated treated 1–6 min at temperature set-points 60°C 80°C. inactivated E. below limits detection (1- 5-log10 inactivation) when operated 80°C set-point with 1-min residence time. Both achieved 1- 3-log10 inactivation bacteria. also pretreatment step grown untreated VH-treated demonstrated similar results, indicating little impact on growth by VH-treatment. However, bioconversion rates were low both substrates (1.6% ± 0.6% 2.1 0.4 sludge).