The potential role of biochar in mitigating gaseous emissions from livestock waste - A mini-review

Authors: CHEN, BAITONG - Iowa State University; Koziel, Jacek; BIALOWIEC, ANDRZEJ - Wroclaw University Of Environmental And Life Sciences; O'BRIEN, SAMUEL - Iowa State University

Submitted to: Journal of Environmental Management
Publication Type: Review Article
Publication Acceptance Date: 9/26/2024
Publication Date: 10/13/2024
Citation: Chen, B., Koziel, J.A., Bialowiec, A., O'Brien, S.C. 2024. The potential role of biochar in mitigating gaseous emissions from livestock waste - A mini-review. Journal of Environmental Management. 370(2024):1-15. https://doi.org/10.1016/j.jenvman.2024.122692.
DOI: https://doi.org/10.1016/j.jenvman.2024.122692

Interpretive Summary: The livestock industry plays a significant role in the economic well-being of many parts of the world with a host of environmental challenges. Key amongst them is decreasing the gaseous emissions from livestock manure. Biochar, a low-cost byproduct of biorenewable energy and thermochemical waste processing, has been actively researched as a potential treatment to mitigate emissions from stored manure. Yet, the efficacy of mitigation differs, partly because biochar properties vary with feedstock and thermochemical processing conditions. Therefore, this review by scientists from ARS-Bushland Texas, Iowa State University and Wroclaw University of Environmental and Life Sciences (Poland) to summarize current knowledge related to mitigating gaseous emissions from manure treated with biochar and has identified a potential synergy between mitigating emissions, improving manure quality, carbon and nitrogen cycling in animal and crop production agriculture. Biochar can be a comprehensive solution to gaseous emissions while also upgrading manure as a high-quality additive that could improve the sustainability of animal and crop production systems.

Technical Abstract: The livestock industry plays a significant role in the economic well-being of many parts of the world with a host of environmental challenges. Key amongst them is the management of gaseous emissions emitted from livestock manure. Mitigation of gaseous emissions from livestock operations such as odor, odorous volatile organic compounds (VOCs), ammonia (NH3), hydrogen sulfide (H2S), and greenhouse gases (GHGs) have been of research interest for the last couple of decades. Biochar, a low-cost byproduct of biorenewable energy and thermochemical waste processing, has been actively researched as a potential surficial treatment of manure and emissions from stored or co-composted manure. Yet, the efficacy of biochar treatment differs, partly because biochar properties vary with feedstock and thermochemical processing conditions. To date, the results from laboratory-scale trials are encouraging, but a more focused effort is needed to bring this technology closer to farm-scale applications. Therefore, this review aims to summarize and highlight current research related to mitigating gaseous emissions from manure treated with biochar. Various types of biochar, and modes of biochar applications, e.g., manure additives and co-composting, dosage, and timing, are discussed in the context of targeted gas emissions mitigation. Gaps in knowledge remain, including demonstrated larger-scale mitigation performance and verifiable technoecomics. Standardization and certification of biochar properties suitable for specific environmental management applications are recommended. The potential synergy between mitigating emissions, improving manure quality, carbon, and nitrogen cycling in animal and crop production agriculture is found. Biochar can be a comprehensive solution to gaseous emissions while also upgrading manure as a high-quality additive that could improve the sustainability of animal and crop production systems.