Kretsloppsteknik

On the 8^th of June, Alice Isibika successfully defended her thesis Use of pre-treatments and substrate blending to enhance process efficiency in black soldier fly larvae composting of food industry waste. External reviewer was Professor Sven Gjedde Sommer from Aarhus University (Denmark). The evaluation committee was Associate Professor Lara Maistrello from University of Modena and Reggio Emilia Area San Lazzaro (Italy), Dr Chrysantus Tanga from International Centre of Insect Physiology and Ecology (Kenya) and Docent Maria Westerholm from SLU here in Uppsala. The reserve in the committee was Docent Åke Nordberg from our own department. Alice got a lot of questions from both the opponent and the committee members, and the defense lasted from 1 pm till 4:30 pm. We think Alice did a great job and congratulate her on this achievement. We wish Alice the best of luck in her future endeavors, and hope that she will be able to apply what she studied in her thesis work also in practice when she returns home to Tanzania.

On Wednesday the 18^th of May 2022, Alice Isibika nailed her PhD Thesis titled ‘Use of pre-treatments and substrate blending to enhance process efficiency in black soldier fly larvae composting of food industry waste’. Welcome to join her public defence of the Thesis that will take place on 8^th of June 2022 at 13.00.

Abstract: Black soldier fly larvae (BSFL) composting is a biowaste treatment that converts biomass into valuable animal protein and fertiliser, but low protein content and complex molecules (e.g. fibre) in substrate reduce BSFL composting efficiency. This thesis evaluated the impact of using pre-treatments and blending substrates on BSFL process efficiency. The feasibility of using BSFL composting to treat available food industry waste streams in Tanzania and physical-chemical characteristics of these wastes were also assessed. The pre-treatments tested were biological, chemical, heat-based, biochemical and combinations of these, while blending involved mixing banana and orange peels with fish waste. All pre-treatments except heating and all substrate blends improved BSFL conversion efficiency in composting. The conversion efficiency was reduced by high concentrations of tannins, phenols, carbohydrates, fibre and fat, but increased by high protein and nitrogen concentrations. The available food industry waste from single companies in Tanzania, in quantities of ~100,000-1,000,000 kg y^-1, was not sufficiently nutritionally balanced as a standalone feedstock for BSFL composting. However, with pre-treatment and substrate blending, BSFL composting could be successfully implemented to valorise biowaste streams in cities in low and middle-income countries such as Tanzania and other similar settings globally.