An innovative continuous self-separation reactor to process rural food waste using black soldier fly larvae

Highlights

	● Rural food waste has stable properties and is suitable as a food source for BSFL.
	● An innovative BSFL continuous self-separation reactor was developed.
	● The single-batch mode operated for 10 d, reducing food waste by 38.9%.
	● The continuous multi-batch mode operated for 32 d, reducing food waste by 56.6%.

Abstract

The utilization of black soldier fly larvae (BSFL) in food waste treatment has garnered significant attention because of its alignment with the principles of a circular economy. However, in rural areas, inadequate management of waste segregation and a high proportion of difficult-to-decompose materials in food waste have reduced the treatment rate by BSFL. After a year-long investigation into rural food waste, we designed a BSFL continuous self-separation reactor, which incorporated microorganisms to enhance waste degradation. The reactor also maintained heat retention, facilitated leachate collection, and enabled the continuous feeding and automated separation of adult black soldier flies. Both single-batch and multi-batch continuous operation modes of the reactor consistently and effectively treated food waste. In the single-batch mode, operation for 10 d resulted in a 38.9% reduction in the wet weight of food waste, with a larval biomass yield of 80.9 g/kg. In the multi-batch continuous mode, operation for 32 d led to a 56.6% reduction in the wet weight of food waste, with a larval biomass yield of 64.7 g/kg. In addition, a 24-h sufficient consumption experiment revealed that the degradation of organic matter in rural food waste was significantly affected by the combined efforts of BSFL and microorganisms. The harvested larvae exhibited high levels of crude protein and crude fat, making them a valuable high-protein, high-fat animal feed. Overall, the reactor demonstrated notable space efficiency and effective waste reduction, providing key insights into the use of BSFL for food waste management.

Graphical abstract

Keywords

Food waste / Black soldier fly larvae / Self-separation reactor / Biomass yield / High-protein animal feed

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Conflict of Interests

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

This work was financially supported by the National Key Research and Development Project (No. 2018YFD1100601-03).

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