(2025) Journal of Environmental Management_Sustainable management of antibiotic-contaminated livestock carcasses for climate change mitigation

Lee D.-J.; Park J.; Kim J.Y.; Kim H.-B.; Kim K.Y.; Kim J.K.; Kwon E.E.

(Academic Press) Journal of Environmental Management ISSN: 3014797 Vol.393 Issue. Article No.126951 DOI: 10.1016/j.jenvman.2025.126951

 Using antibiotics in livestock farming has raised serious concerns, particularly about greenhouse gas (GHG) emissions and the discharge of residual antibiotics from livestock carcasses (LSC). Due to the low C-to-N ratio (≤4.4) and persistent antibiotic residues post-rendering, dead livestock are not suitable for conventional treatments such as composting and anaerobic digestion. This study presents a thermochemical conversion strategy using carbon dioxide (CO₂) as a mild oxidant. CO₂ facilitated gas-phase reactions with pyrolytic volatile matter, shifting carbon distribution toward valuable syngas production and minimising unwanted condensable products. Multi-stage pyrolysis yielded only modest gains due to reaction rate limitation, catalytic pyrolysis with a Ni-based catalyst increased syngas production to 25.91 mmol g−1 under CO₂ (an increase of 28 % over N₂ conditions). CO₂ contributes to the degradation of polycyclic aromatic hydrocarbons (PAHs) and residual antibiotics, improving the environmental safety of the pyrolysis process. The CO₂-assisted pyrolysis had a lower carbon footprint (−0.42 g CO₂-eq g−1), compared to landfilling, which had higher emissions (16.48 g CO₂-eq g−1). These findings reveal a carbon-negative, resource-efficient method for safely and sustainably treating antibiotic-contaminated carcass waste. © 2025 Elsevier Ltd

This study was supported by the "Cooperative Research Program for Agriculture Science and Technology Development" (grant number RS-2022-RD010000) of the Rural Development Administration of the Republic of Korea.