High Value Organic Waste Treatment via Black Soldier Fly Bioconversion : Onsite Pilot Study

Abstract: The desire for value addition to the organic waste management chain at Högbytorp using the Black Soldier Fly (BSF) process, as well as the problem of the escalating demand for protein in livestock feed motivated this study. Good quality crop land is devoted to growing feed for animals at the expense of human food, and ironically with a full understanding of the associated environmental footprints. Black Soldier Fly Larvae (BSFL) feed on organic waste voraciously while building their body composition of 40% protein and 30% fat. Their protein can be used in animal feedstock and pet food, replacing the more expensive but nutritionally comparable fishmeal, while their fat can be used for biodiesel production. They can also reduce a waste pile significantly, minimizing possible pollution. In this study, the process was tried on various waste streams (fruits, manure and ‘slurry reject’) at Högbytorp. Biomass conversion, larval fat and protein content, compost by-product characteristics and residence time requirements for each stream were assessed. The study involved literature review, chemical analyses and experimental design (rearing BSFL on waste through their lifecycle). The study yielded waste reduction up to 83% and fat and protein contents up to 42% and 41% respectively, depending on the waste stream. The residence time depended on the age at which the larvae started feeding, but ranged between 8-11 days. If applied in organic waste management chain, the process could contribute to greener energy provision (biodiesel) as well as sustainable protein provision to the animal, fish and pet industries. It could further reduce waste amounts significantly and generate income while contributing to the saving of Earth’s limited resources.