Challenges

Harnessing flies for recycling food waste in cities

The idea of harnessing flies for recycling waste while creating natural fertilizer and livestock feed is also gaining traction in cities located in Asian countries like China, Indonesia and Singapore.

Requirements to apply this process:

  1. A type of fly called Black Soldier, which is an insect known as Hermetia illucens. However there are also another fly species who can also be used. The decision of the type of fly will depend on the composition of the food waste.
  2. It is recommendable to have an estimated amount of produced food waste in order to dimension and design the facilities.

The process works this way:

The collected kitchen waste will be automatic sorted, crushed, bio-deodorized, processed into Black Soldier Fly’s food, and finally produce the larvae and frass.  A city with the population of 1 million will generate about 100 tons of kitchen waste every day (more or less), including 60 tons dry matter. This can produce 20 tons of larva and 40 tons of fertilizer. The larva can be used as a high-protein feed for Citizen Farm's chickens. There are however research that investigated the feasibility of using the larva as feed for fish. See: https://journals.sagepub.com/doi/abs/10.1177/0734242X09103838?journalCo…

I want to share with all of you this amazing video of how China is working with the kitchen waste, it explains really well what i described lines above.

http://www.climatesolver.org/innovations/eating/kitchen-waste-recycling…

The same way in Singapore, they are not only applying this solution but they continue investigating how to make the process more efficient. A team in the Department of Biological Science at the National University of Singapore is exploring how they can change the black soldier fly's behavior to maximize its food waste processing potential. The aim of the project is to make the larvae efficient feeders, so that half the amount of larvae can eat the same amount of food waste in half the space.

https://www.usnews.com/news/cities/articles/2018-10-25/in-singapore-usi…

Finally, here some more compiled research of different universities in case it wakes up your interest :)

https://www.wageningenacademic.com/doi/pdf/10.3920/JIFF2018.S1

 

 

Comments (2)

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How can this be improved?
Laura Scherer
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  • Interesting! But why do the organic wastes have to be boo-deodorized? How does that work and which steps follow to process the material before the flies can eat it?
    Could these steps also be left out?

    Vanessa Leslie Bolivar Paypay
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  • The bio deodorized works to naturally eliminate the source of bad odors by turning them into nature’s most basic compounds, water and carbon dioxide. If it was not applied odors will appear due to the descomposition of organic matter. However, in a US Patent i saw they also use an air-scrubbing system for deodorizing, so there are alternatives. I would say this step could be left out but that may cause odor problems lately and hygiene issues. In digestion process, this larvae assimilate nutrients o
    f the organic matter.

    Next comes, black soldier fly larva cuts down the amount of organic waste. Soldier flies lay about 600 eggs each before they die five to eight days later. The eggs take four days to hatch into larvae that eat five times their body weight daily. After several days of feeding the larvae can be turned into nutrient-rich feed for fish or chickens. In other facilities, a small percentage of the larvae are also allowed to turn into pupae, which metamorphose into flies a week later, and the cycle begins again. To your question about what should happen to the material before being treated by the flies, this material should be in a room unnder controlled environmental conditions, for example (temperature: 27 ± 2ºC, relative humidity: 65 ± 5%, and photoperiod Light
    :Dark = 12:12 hours), it may vary from facility to facility.

    here the patent https://patents.google.com/patent/US6391620B1/en with insightful technical details of a process.