Performance evaluation of black soldier fly larvae fed on human faeces, food waste and their mixture

In this study, Black Soldier Fly Larvae (BSFL)-based technology has been proposed and tested for treatment and valorization of human faeces, food waste and a mixture of 75% human faeces with 25% food waste. Experiments were conducted between 15 and 45 °C and 55-75% relative humidity. BSFL's performance for the degradation of the mixed waste was significantly better than their performances when used for the degradation of either human faeces or food waste fed alone, primarily due to the availability of more conducive pH, and better microbial and nutrient balance. The abiotic factors, temperature and relative humidity impacted the decomposition rate and weight gain pattern of BSFL when they were fed on the waste streams. The results showed that the optimum conditions to conduct the proposed BSFL-based treatment was 31-35 °C and 55-75% RH. The protein content in the BSFL was not impacted significantly by the quality of the waste stream, whereas the fat content varied substantially. The abiotic factors also impacted the protein and fat content of BSFL. The investigation led to the estimation of the decomposition rates over a wide range of temperature and relative humidity conditions, which could be useful for the design of large-scale BSFL-based treatment plants.