The study evaluated some technical aspects associated with larvae growth, ventilation and drying demands in a pilot sized black soldier fly treatment system treating segregated household food waste and discussed models to describe the treatment process and its energy efficiency.
The aim of the study was to evaluate GHG and ammonia (NH3) emissions from fly larvae composting treatment of food waste and the effects of pre-treatment and seeding of the food waste substrate with BSF larvae-associated bacteria on the efficiency and rate of the fly larvae composting process.
On the 5th and 6th of September Giulio attended to the Isecta conference in Potzdam (Germany). The conference gave valuable insights and the latest finding on the topic of insects for food and feed covering several aspects of the sector, from the legislation point of view to basic research and optimisation of rearing systems. At the event attended more than 230 people between scientist and businesses from 38 countries underling the growth of the sector and public interest on the topic.
Evgheni Ermolaev and Nils Ewald from SLU Kretsloppsteknik together with Vesa Hiltula and Benny Björk from Eskilstuna Strängnäs Energi och Miljö AB presented the latest research results and the large-scale implementation progress of the fly lave composting system developed in the group from 2011. Matology is a yearly exhibition held by SLU in Stockholm with focus highlighting the latest trends in sustainable food systems.
In the last week of May, SLU was arranging the “Thesis Day”-event for the second year in a row. This was an opportunity for bachelor’s and master’s students to present their degree projects in the form of scientific posters. Six students were also chosen to arrange oral presentations of their projects. Nils Ewald was one of these students. As you might remember, Nils finished his master’s thesis about the fatty acid composition of the black soldier fly larvae earlier this spring.
In the past 2
years, the environmental engineering group has been collaborating with the
waste management company of Eskilstuna in order to treat food waste with black
soldier fly larvae. This technology, developed within the group over the past
10 years, aims to recover the nutrients present in organic waste streams and reintroduce
them into the food chain by producing feed for livestock. With this collaboration,
a pilot plant was set up with the goal of treating 1 ton of food waste per day.
After having successfully achieved a stable production of 1 million young
larvae per day in the fly colony at SLU, the next step was to treat 1 ton of
food waste with the larvae at the pilot plant. Not only did we managed to treat
1 ton of food waste per day but recently managed to double the treated food
waste reaching 2 tons per day. Right now, we are back in the lab to analyse the
This year’s event had
the theme below the surface, and
brought up a wide range of interesting topics; from deep-sea research to the psychology
of how we look at and manage the threat of climate change. At dinner Axfoundation presented their vision
of future food and that’s where we came into the picture. On the menu were
cabbage and pumpkin fertilized with frass (insect compost) from our fly larvae reared
on food waste, served with chicken and rainbow trout that had insects as their
main protein source. The larvae used in the feed were reared on reclaimed bread
and vegetable waste from Sorunda grönsakshallar.
On the 12th of March we had a visit from our colleagues at the Norwegian Institute of Bioeconomy Research (NIBIO). On the visit came Trond Mæhlum, Bente Føreid, Thorsten Heidorn and Anders Enoksen. From our group Björn Vinnerås, Jennifer McConville and Cecilia Lalander joined. We presented about our different ongoing projects on safe nutrient recycling: Björn presented on urine drying and Cecilia on fly larvae composting while Jennifer presented her work on the readiness of the Swedish wastewater sector for a technology transition. We were updated on an ongoing project on sustainable and circular urban farming systems that is a collaboration between stakeholders in Europe and China (Sino-European innovative green and smart cities). We were happy to know that the delegation from Norway come to visit us for inspiration on possible technologies. We hope that we in the future will be able to collaborate on some of these exciting technologies.
Just at the end of January, Kristina Lundgren presented her master thesis at Uppsala University. The aim of the thesis was to increase the understanding of how bacteria may affect fly larvae composting with the black soldier fly. The results showed no significant impact on the survival, final biomass or reduction of substrate when bacteria isolated from BSF eggs where inoculated into the substrate (food waste). However, interestingly the variation in resulting biomass and material reduction was decreased when any bacteria or group of bacteria were added to the food waste. Hence, the system became easier to predict, which especially is desirable when scaling up the system. The audience seemed intrigued by fly larvae composting as a waste management tool and had questions both regarding large scale facilities and the possibility that inoculation bacteria might yield positive effects in other substrates.