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

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

Highlight

	● 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%.

References

[1] Bai L, Deng Y, Li J, Ji M, Ruan W. (2020). Role of the proportion of cattle manure and biogas residue on the degradation of lignocellulose and humification during composting. Bioresource Technology, 307: 122941

[2] Cheng J Y K, Chiu S L H, Lo I M C. (2017). Effects of moisture content of food waste on residue separation, larval growth and larval survival in black soldier fly bioconversion. Waste Management, 67: 315–323

[3] Du S, Zhang M, Zhang S, Wen X, Wang Y, Wu D. (2024). Evaluation of the quality of products from multiple industrial-scale composting treatment facilities for kitchen waste and exploration of influencing factors. Environmental Research, 262: 119899

[4] Falabella P, Chia S Y, Tanga C M, Khamis F M, Mohamed S A, Salifu D, Sevgan S, Fiaboe K K M, Niassy S, Van Loon J J A. . (2018). Threshold temperatures and thermal requirements of black soldier fly Hermetia illucens: implications for mass production. PLoS One, 13(11): e0206097

[5] Gold M, Cassar C M, Zurbrügg C, Kreuzer M, Boulos S, Diener S, Mathys A. (2020). Biowaste treatment with black soldier fly larvae: increasing performance through the formulation of biowastes based on protein and carbohydrates. Waste Management, 102: 319–329

[6] Hopkins I, Newman L P, Gill H, Danaher J. (2021). The influence of food waste rearing substrates on black soldier fly larvae protein composition: a systematic review. Insects, 12(7): 608

[7] Isibika A, Simha P, Vinnerås B, Zurbrügg C, Kibazohi O, Lalander C. (2023). Food industry waste: an opportunity for black soldier fly larvae protein production in Tanzania. Science of the Total Environment, 858: 159985

[8] Jiang C L, Jin W Z, Tao X H, Zhang Q, Zhu J, Feng S Y, Xu X H, Li H Y, Wang Z H, Zhang Z J. (2019). Black soldier fly larvae (Hermetia illucens) strengthen the metabolic function of food waste biodegradation by gut microbiome. Microbial Biotechnology, 12(3): 528–543

[9] Lalander C, Diener S, Zurbrügg C, Vinnerås B. (2019). Effects of feedstock on larval development and process efficiency in waste treatment with black soldier fly (Hermetia illucens). Journal of Cleaner Production, 208: 211–219

[10] Ma C, Huang Z, Feng X, Memon F U, Cui Y, Duan X, Zhu J, Tettamanti G, Hu W, Tian L. (2024). Selective breeding of cold-tolerant black soldier fly (Hermetia illucens) larvae: gut microbial shifts and transcriptional patterns. Waste Management, 177: 252–265

[11] Mohan K, Sathishkumar P, Rajan D K, Rajarajeswaran J, Ganesan A R. (2023). Black soldier fly (Hermetia illucens) larvae as potential feedstock for the biodiesel production: recent advances and challenges. Science of the Total Environment, 859: 160235

[12] Nguyen T T X, Tomberlin J K, Vanlaerhoven S. (2015). Ability of black soldier fly (Diptera: Stratiomyidae) larvae to recycle food waste. Environmental Entomology, 44(2): 406–410

[13] Parra-Orobio B A, Soto-Paz J, Hernández-Cruz J A, Gómez-Herreño M C, Domínguez-Rivera I C, Ocaña-Oviedo E R. (2023). Evaluation of biochar as an additive in the co-composting of green waste and food waste. Sustainability, 15(9): 7437

[14] ProgrammeU N E (2024). Food Waste Index Report 2024. Nairobi: United Nations Environment Programme

[15] Salemdeeb R, Zu Ermgassen E K H J, Kim M H, Balmford A, Al-Tabbaa A. (2017). Environmental and health impacts of using food waste as animal feed: a comparative analysis of food waste management options. Journal of Cleaner Production, 140: 871–880

[16] Shumo M, Osuga I M, Khamis F M, Tanga C M, Fiaboe K K M, Subramanian S, Ekesi S, Van Huis A, Borgemeister C. (2019). The nutritive value of black soldier fly larvae reared on common organic waste streams in Kenya. Scientific Reports, 9(1): 10110

[17] Siddiqui S A, Ristow B, Rahayu T, Putra N S, Widya Yuwono N, Nisa K, Mategeko B, Smetana S, Saki M, Nawaz A. . (2022). Black soldier fly larvae (BSFL) and their affinity for organic waste processing. Waste Management, 140: 1–13

[18] Singh A, Srikanth B H, Kumari K. (2021). Determining the black soldier fly larvae performance for plant-based food waste reduction and the effect on biomass yield. Waste Management, 130: 147–154

[19] Taufek N M, Mohamad Zulkifli N F N, Hamizah A N. (2024). Upcycling of food waste generated from the fresh market by utilising black soldier fly larvae: influence on growth, bioconversion, and nutritional composition. Journal of Environmental Management, 349: 119467

[20] Wald C. (2017). The new economy of excrement. Nature, 549(7671): 146–148

[21] Wang H, Qin Y, Xin L, Zhao C, Ma Z, Hu J, Wu W. (2023). Preliminary techno-economic analysis of three typical decentralized composting technologies treating rural kitchen waste: a case study in China. Frontiers of Environmental Science & Engineering, 17(4): 47

[22] Xiang F, Zhang Q, Xu X, Zhang Z. (2024). Black soldier fly larvae recruit functional microbiota into the intestines and residues to promote lignocellulosic degradation in domestic biodegradable waste. Environmental Pollution, 340: 122676

[23] Xue Y, Xiao K, Wu X, Sun M, Liu Y, Ou B, Yang J. (2023). Insights into the changes of amino acids, microbial community, and enzymatic activities related with the nutrient quality of product during the composting of food waste. Frontiers of Environmental Science & Engineering, 17(3): 35

[24] Zhan S, Fang G, Cai M, Kou Z, Xu J, Cao Y, Bai L, Zhang Y, Jiang Y, Luo X. . (2020). Genomic landscape and genetic manipulation of the black soldier fly Hermetia illucens, a natural waste recycler. Cell Research, 30(1): 50–60

[25] Zhao S, Schmidt S, Gao H, Li T, Chen X, Hou Y, Chadwick D, Tian J, Dou Z, Zhang W. . (2022). A precision compost strategy aligning composts and application methods with target crops and growth environments can increase global food production. Nature Food, 3(9): 741–752

[26] Zulkifli S, Jayanegara A, Pramudya B, Fahmi M R, Rahmadani M. (2023). Alleviation of selected environmental waste through biodegradation by black soldier fly (Hermetia illucens) larvae: a meta-analysis. Recycling, 8(6): 83

RIGHTS & PERMISSIONS

Higher Education Press 2025