Biodegradation of waste refrigerator polyurethane by mealworms

Highlights

● Waste refrigerator polyurethane (WRPU) was ingested and biodegraded by mealworms.

● The carbon in WRPU-based frass was lower than that in WRPU.

● Urethane groups in WRPU were broken down after ingestion by mealworms.

● Thermal stability of WRPU-based frass were deteriorated compared to that of WRPU.

● Gut microbiomes of mealworms fed using WRPU were distinct from that fed using bran.

Abstract

Refrigerator insulation replacement results in discarding a large amount of waste refrigerator polyurethane (WRPU). Insect larvae like mealworms have been used to biodegrade pristine plastics. However, knowledge about mealworms degrading WRPU is scarce. This study presents an in-depth investigation of the degradation of WRPU by mealworms using the micro-morphology, composition, and functional groups of WRPU and the egested frass characteristics. It was found that the WRPU debris in frass was scoured, implying that WRPU was ingested and degraded by mealworms. The carbon content of WRPU-based frass was lower than that of WRPU, indicating that mealworms utilized WRPU as a carbon source. The urethane groups in WRPU were broken, and benzene rings’ C=C and C–H bonds in the isocyanate disappeared after being ingested by mealworms. Thermal gravimetric-differential thermal gravimetry analysis showed that the weight loss temperature of WRPU-based frass was 300 °C lower than that of WRPU, indicating that the thermal stability of WRPU deteriorated after being ingested. The carbon balance analysis confirmed that carbon in the ingested WRPU released as CO₂ increased from 18.84 % to 29.80 %, suggesting that WRPU was partially mineralized. The carbon in the mealworm biomass ingesting WRPU decreased. The possible reason is that WRPU does not supply sufficient nutrients for mealworm growth, and the impurities and odor present in WRPU affect the appetite of the mealworms. The microbial community analysis indicated that WRPU exerts a considerable effect on the gut microorganism of mealworms. These findings confirm that mealworms degrade WRPU.

Graphical abstract

Keywords

Waste refrigerator polyurethane / Mealworms / Biodegradation / Carbon balance / Gut microorganism

References

[1] Akindoyo J O , Beg M D H , Ghazali S , Islam M R , Jeyaratnam N , Yuvaraj A R . (2016). Polyurethane types, synthesis and applications: a review. RSC Advances, 6(115): 114453–114482

[2] Badola N , Bahuguna A , Sasson Y , Chauhan J S . (2022). Microplastics removal strategies: a step toward finding the solution. Frontiers of Environmental Science & Engineering, 16(1): 7

[3] Beran R , Zarybnicka L , Machova D . (2020). Recycling of rigid polyurethane foam: Micro-milled powder used as active filler in polyurethane adhesives. Journal of Applied Polymer Science, 137(1): e49095

[4] Brandon A M , Gao S H , Tian R M , Ning D L , Yang S S , Zhou J Z , Wu W M , Criddle C S . (2018). Biodegradation of polyethylene and plastic mixtures in mealworms (larvae of Tenebrio molitor) and effects on the gut microbiome. Environmental Science & Technology, 52(11): 6526–6533

[5] Bulak P , Proc K , Pytlak A , Puszka A , Gawdzik B , Bieganowski A . (2021). Biodegradation of different types of plastics by Tenebrio molitor insect. Polymers, 13(20): 3508

[6] Caravelli A , Giannuzzi L , Zaritzky N . (2004). Effect of chlorine on filamentous microorganisms present in activated sludge as evaluated by respirometry and INT-dehydrogenase activity. Water Research, 38(9): 2395–2405

[7] Charitopoulou M A , Kalogiannis K G , Lappas A A , Achilias D S . (2021). Novel trends in the thermo-chemical recycling of plastics from WEEE containing brominated flame retardants. Environmental Science and Pollution Research International, 28(42): 59190–59213

[8] Dement’ev A G , Khlystalova T K , Demina A I , Zinger P A . (1991). Structural-physical properties of foam polyurethanes with various foaming agents. Polymer Science USSR, 33(10): 2125–2134

[9] Demets R, Roosen M, Vandermeersch L, Ragaert K, Walgraeve C, De Meester S (2020). Development and application of an analytical method to quantify odour removal in plastic waste recycling processes. Resources, Conservation& Recycling, 161: 104907

[10] Fesseha H , Abebe F . (2019). Degradation of plastic materials using microorganisms: a review. Public Health – Open Journal, 4(2): 57–63

[11] Gong W , Xing Y , Han L , Lu A , Qu H , Xu L . (2022). Occurrence and distribution of micro- and mesoplastics in the high-latitude nature reserve, northern China. Frontiers of Environmental Science & Engineering, 16(9): 113

[12] Guo B , Yin J , Hao W , Jiao M . (2019). Polyurethane foam induces epigenetic modification of mitochondrial DNA during different metamorphic stages of Tenebrio molitor. Ecotoxicology and Environmental Safety, 183: 109461

[13] Kang J J , Lee J S , Yang W S , Park S W , Alam M T , Back S K , Choi H S , Seo Y C , Yun Y S , Gu J H , Saravanakumar A , Kumar K V . (2016). A study on environmental assessment of residue from gasification of polyurethane waste in E-Waste recycling process. Procedia Environmental Sciences, 35: 639–642

[14] Kay M J , Morton L H G , Prince E L . (1991). Bacterial degradation of polyester polyurethane. International Biodeterioration, 27(2): 205–222

[15] Khan S , Nadir S , Dong Y , Schaefer D A , Mortimer P E , Gui H , Khan A , Yu M , Iqbal S , Sheng J , Xu J . (2020). Biodegradation of polyester polyurethane by Aspergillus flavus G10. BioRxiv, 2020: 170654

[16] Khan S , Nadir S , Shah Z U , Shah A A , Karunarathna S C , Xu J , Khan A , Munir S , Hasan F . (2017). Biodegradation of polyester polyurethane by Aspergillus tubingensis. Environmental Pollution, 225: 469–480

[17] Kim H R , Lee H M , Yu H C , Jeon E , Lee S , Li J , Kim D H . (2020). Biodegradation of polystyrene by Pseudomonas sp. isolated from the gut of superworms (larvae of Zophobas atratus). Environmental Science & Technology, 54(11): 6987–6996

[18] Kwadha C A , Mutunga J M , Irungu J , Ongamo G , Ndegwa P , Raina S , Fombong A T . (2019). Decanal as a major component of larval aggregation pheromone of the greater wax moth, Galleria mellonella. Journal of Applied Entomology, 143(4): 417–429

[19] Li Q , Wang J , Chen L , Shi H , Hao J . (2019). Ammonium polyphosphate modified with β-cyclodextrin crosslinking rigid polyurethane foam: enhancing thermal stability and suppressing flame spread. Polymer Degradation & Stability, 161: 166–174

[20] Li X , Li M , Mei Q , Niu S , Wang X , Xu H , Dong B , Dai X , Zhou J L . (2021). Aging microplastics in wastewater pipeline networks and treatment processes: physicochemical characteristics and Cd adsorption. Science of the Total Environment, 797: 148940

[21] Liu J , He J , Xue R , Xu B , Qian X , Xin F , Blank L M , Zhou J , Wei R , Dong W , Jiang M . (2021). Biodegradation and up-cycling of polyurethanes: progress, challenges, and prospects. Biotechnology Advances, 48: 107730

[22] Liu P , Zhan X , Wu X , Li J , Wang H , Gao S . (2020). Effect of weathering on environmental behavior of microplastics: properties, sorption and potential risks. Chemosphere, 242: 125193

[23] Lou Y , Ekaterina P , Yang S S , Lu B , Liu B , Ren N , Corvini P F X , Xing D . (2020). Biodegradation of polyethylene and polystyrene by greater wax moth larvae (Galleria mellonella L.) and the effect of Co-diet supplementation on the core gut microbiome. Environmental Science & Technology, 54(5): 2821–2831

[24] Luo L , Wang Y , Guo H , Yang Y , Qi N , Zhao X , Gao S , Zhou A . (2021). Biodegradation of foam plastics by zophobas atratus larvae (Coleoptera: Tenebrionidae) associated with changes of gut digestive enzymes activities and microbiome. Chemosphere, 282: 131006

[25] Magnin A , Hoornaert L , Pollet E , Laurichesse S , Phalip V , Averous L . (2019). Isolation and characterization of different promising fungi for biological waste management of polyurethanes. Microbial Biotechnology, 12(3): 544–555

[26] Magnin A , Pollet E , Phalip V , Averous L . (2020). Evaluation of biological degradation of polyurethanes. Biotechnology Advances, 39: 107457

[27] Maitra J , Shukla V K . (2014). Cross-linking in hydrogels: a review. American Journal of Political Science, 4(2): 25–31

[28] National Bureau of Statistics of China (2009). China Statistical Yearbook. Output of Industrial Products. 2009. Beijing: China Statistics Press (in Chinese)

[29] National Bureau of Statistics of China (2021). China Statistical Yearbook. Output of Industrial Products. 2021. Beijing: China Statistics Press (in Chinese)

[30] Nowak V , Persijn D , Rittenschober D , Charrondiere U R . (2016). Review of food composition data for edible insects. Food Chemistry, 193: 39–46

[31] Oprea S . (2010). Dependence of fungal biodegradation of PEG/castor oil-based polyurethane elastomers on the hard-segment structure. Polymer Degradation & Stability, 95(12): 2396–2404

[32] Oprea S , Potolinca V O , Gradinariu P , Oprea V . (2018). Biodegradation of pyridine-based polyether polyurethanes by the Alternaria tenuissima fungus. Journal of Applied Polymer Science, 135(14): 46096

[33] Panda S S , Panda B P , Nayak S K , Mohanty S . (2018). A review on waterborne thermosetting polyurethane coatings based on castor oil: synthesis, characterization, and application. Polymer-Plastics Technology and Engineering, 57(6): 500–522

[34] Park J , Jung I , Lee K , Kim M , Hwang J , Choi W . (2018). Case study in Korea of manufacturing SRF for polyurethanes recycling in e-wastes. Journal of Material Cycles and Waste Management, 20(4): 1950–1960

[35] Pellizzi E , Lattuati-Derieux A , Lavédrine B , Cheradame H . (2014). Degradation of polyurethane ester foam artifacts: chemical properties, mechanical properties and comparison between accelerated and natural degradation. Polymer Degradation & Stability, 107: 255–261

[36] Peng B Y , Chen Z , Chen J , Yu H , Zhou X , Criddle C S , Wu W M , Zhang Y . (2020). Biodegradation of polyvinyl chloride (PVC) in Tenebrio molitor (Coleoptera: Tenebrionidae) larvae. Environment International, 145: 106106

[37] Peng B Y , Chen Z , Chen J , Zhou X , Wu W M , Zhang Y . (2021). Biodegradation of polylactic acid by yellow mealworms (larvae of Tenebrio molitor) via resource recovery: a sustainable approach for waste management. Journal of Hazardous Materials, 416: 125803

[38] Peng B Y , Su Y , Chen Z , Chen J , Zhou X , Benbow M E , Criddle C S , Wu W M , Zhang Y . (2019). Biodegradation of polystyrene by dark (Tenebrio obscurus) and yellow (Tenebrio molitor) mealworms (Coleoptera: Tenebrionidae). Environmental Science & Technology, 53(9): 5256–5265

[39] Peng Y H , Shih Y H , Lai Y C , Liu Y Z , Liu Y T , Lin N C . (2014). Degradation of polyurethane by bacterium isolated from soil and assessment of polyurethanolytic activity of a Pseudomonas putida strain. Environmental Science and Pollution Research International, 21(16): 9529–9537

[40] Shilpa N , Basak S S . (2022). Microbial biodegradation of plastics: challenges, opportunities, and a critical perspective. Frontiers of Environmental Science & Engineering, 16(12): 161

[41] Sun Q , Li J , Wang C , Chen A , You Y , Yang S , Liu H , Jiang G , Wu Y , Li Y . (2022). Research progress on distribution, sources, identification, toxicity, and biodegradation of microplastics in the ocean, freshwater, and soil environment. Frontiers of Environmental Science & Engineering, 16(1): 1

[42] Tantisattayakul T , Kanchanapiya P , Methacanon P . (2018). Comparative waste management options for rigid polyurethane foam waste in Thailand. Journal of Cleaner Production, 196: 1576–1586

[43] Terakado O , Yanase H , Hirasawa M . (2014). Pyrolysis treatment of waste polyurethane foam in the presence of metallic compounds. Journal of Analytical and Applied Pyrolysis, 108: 130–135

[44] Wu Q , Tao H , Wong M H . (2019). Feeding and metabolism effects of three common microplastics on Tenebrio molitor L. Environmental Geochemistry and Health, 41(1): 17–26

[45] Yang L , Gao J , Liu Y , Zhuang G , Peng X , Wu W M , Zhuang X . (2021a). Biodegradation of expanded polystyrene and low-density polyethylene foams in larvae of Tenebrio molitor Linnaeus (Coleoptera: Tenebrionidae): Broad versus limited extent depolymerization and microbe-dependence versus independence. Chemosphere, 262: 127818

[46] Yang S S , Brandon A M , Andrew Flanagan J C , Yang J , Ning D , Cai S Y , Fan H Q , Wang Z Y , Ren J , Benbow E , Ren N Q , Waymouth R M , Zhou J , Criddle C S , Wu W M . (2018). Biodegradation of polystyrene wastes in yellow mealworms (larvae of Tenebrio molitor Linnaeus): Factors affecting biodegradation rates and the ability of polystyrene-fed larvae to complete their life cycle. Chemosphere, 191: 979–989

[47] Yang S S , Chen Y D , Kang J H , Xie T R , He L , Xing D F , Ren N Q , Ho S H , Wu W M . (2019a). Generation of high-efficient biochar for dye adsorption using frass of yellow mealworms (larvae of Tenebrio molitor Linnaeus) fed with wheat straw for insect biomass production. Journal of Cleaner Production, 227: 33–47

[48] Yang S S , Ding M Q , He L , Zhang C H , Li Q X , Xing D F , Cao G L , Zhao L , Ding J , Ren N Q , Wu W M . (2021b). Biodegradation of polypropylene by yellow mealworms (Tenebrio molitor) and superworms (Zophobas atratus) via gut-microbe-dependent depolymerization. Science of the Total Environment, 756: 144087

[49] Yang S S , Ding M Q , Zhang Z R , Ding J , Bai S W , Cao G L , Zhao L , Pang J W , Xing D F , Ren N Q , Wu W M . (2021c). Confirmation of biodegradation of low-density polyethylene in dark- versus yellow- mealworms (larvae of Tenebrio obscurus versus Tenebrio molitor) via. gut microbe-independent depolymerization. Science of the Total Environment, 789: 147915

[50] Yang S S, Wu W M (2020). Microplastics in terrestrial environments - emerging contaminants and major challenges. In: He D F, Luo Y M, eds. Control approaches for microplastics in terrestrial environments. Part V. Biodegradation of Plastics in Tenebrio Genus (mealworms). Cham: Springer Nature Switzerland AG, 385–422

[51] Yang W , Dong Q , Liu S , Xie H , Liu L , Li J . (2012). Recycling and disposal methods for polyurethane foam wastes. Procedia Environmental Sciences, 16: 167–175

[52] Yang X , Song Z , Zhou S , Guo H , Geng B , Peng X , Zhao G , Xie Y . (2019b). Insights into functional microbial succession during nitrogen transformation in an ectopic fermentation system. Bioresource Technology, 284: 266–275

[53] Yang Y , Yang J , Wu W M , Zhao J , Song Y , Gao L , Yang R , Jiang L . (2015a). Biodegradation and mineralization of polystyrene by plastic-eating mealworms: Part 1. Chemical and physical characterization and isotopic tests. Environmental Science & Technology, 49(20): 12080–12086

[54] Yang Y , Yang J , Wu W M , Zhao J , Song Y , Gao L , Yang R , Jiang L . (2015b). Biodegradation and mineralization of polystyrene by plastic-eating mealworms: Part 2. Role of gut microorganisms. Environmental Science & Technology, 49(20): 12087–12093

[55] Yazici B, Can Z S, Calli B (2014). Prediction of future disposal of end-of-life refrigerators containing CFC-11. Waste Management (New York, N.Y.), 34(1): 162–166

[56] Yuan Y , Ma C , Shi Y , Song L , Hu Y , Hu W . (2018). Highly-efficient reinforcement and flame retardancy of rigid polyurethane foam with phosphorus-containing additive and nitrogen-containing compound. Materials Chemistry and Physics, 211: 42–53

[57] Zhang J , Gao D , Li Q , Zhao Y , Li L , Lin H , Bi Q , Zhao Y . (2020a). Biodegradation of polyethylene microplastic particles by the fungus Aspergillus flavus from the guts of wax moth Galleria mellonella. Science of the Total Environment, 704: 135931

[58] Zhang M , Luo Z , Zhang J , Chen S , Zhou Y . (2015). Effects of a novel phosphorus-nitrogen flame retardant on rosin-based rigid polyurethane foams. Polymer Degradation & Stability, 120: 427–434

[59] Zhang Y , Li F , Peng N , Peng L . (2020b). Environmental impact assessment of air-permeable plastic runway production in China. Science of the Total Environment, 730: 139073

[60] Zhao X, Duan H, Li J (2011). An evaluation on the environmental consequences of residual CFCs from obsolete household refrigerators in China. Waste Management (New York, N.Y.), 31(3): 555–560

[61] Zhu P , Pan X , Li X , Liu X , Liu Q , Zhou J , Dai X , Qian G . (2021). Biodegradation of plastics from waste electrical and electronic equipment by greater wax moth larvae (Galleria mellonella). Journal of Cleaner Production, 310: 127346

[62] Zhu P , Shen Y , Li X , Liu X , Qian G , Zhou J . (2022). Feeding preference of insect larvae to waste electrical and electronic equipment plastics. Science of the Total Environment, 807: 151037

Acknowledgements

The authors are grateful for support from the National Key R&D Program of China (Nos. 2019YFC0408204, 2018YFC1903201, and 2018YFC0213605), the Shanghai Committee of Science and Technology (China) (No. 19DZ1204702), the National Natural Scientific Foundation of China (No. 52070126) and the Joint Projects of Shanghai University grant (China) 202142.

Electronic Supplementary Material

Supplementary material is available in the online version of this article at https://doi.org/10.1007/s11783-023-1638-8 and is accessible for authorized users.

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