Skip to main content
ARS Home » Plains Area » Bushland, Texas » Conservation and Production Research Laboratory » Livestock Nutrient Management Research » Research » Publications at this Location » Publication #418163

Research Project: Strategies to Manage Feed Nutrients, Reduce Gas Emissions, and Promote Soil Health for Beef and Dairy Cattle Production Systems of the Southern Great Plains

Location: Livestock Nutrient Management Research

Title: Qualitative assessment of hazardous gas emissions from sewage sludge-derived biochar

Author
item SYGULA, EWA - Wroclaw University Of Environmental And Life Sciences
item LESNIAK, MALGORZATA - Wroclaw University Of Environmental And Life Sciences
item BOBAK, LUKASZ - Wroclaw University Of Environmental And Life Sciences
item Koziel, Jacek
item BIALOWIEC, ANDRZEJ - Wroclaw University Of Environmental And Life Sciences

Submitted to: Water
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/27/2024
Publication Date: 12/29/2024
Citation: Sygula, E., Lesniak, M., Bobak, L., Koziel, J.A., Bialowiec, A. 2025. Qualitative assessment of hazardous gas emissions from sewage sludge-derived biochar. Water. 17(1):Article w17010058. Available: https://doi.org/10.3390/w17010058.
DOI: https://doi.org/10.3390/w17010058

Interpretive Summary: Adding value to abundant waste materials have been proposed to improve the economic well-being of many parts of the world and environmental sustainability. Thermal treatment of sewage sludge generates biochar that can potentially be used in agriculture or as an alternative fuel. Yet, the biochar production itself carries the risk of emitting harmful volatile organic compounds (VOCs). Unfortunately, safety of biochar production is poorly understood. Accordingly, researchers from ARS (Bushland) and Wroclaw University of Environmental and Life Sciences (Poland) demonstrated a release of hazardous VOC emissions during biochar storage. This finding helps improving biochar storage design aiming to lower the risk of occupational exposure to VOCs. Monitoring air pollutants, tracking the highest permissible concentrations and workers exposure, as well as the use of personal protective equipment is recommended.

Technical Abstract: Approximately 10 million megagrams of sewage sludge is produced each year in the European Union alone. To date, options to utilize sewage sludge are limited. Local regulations and sludge characteristics strictly determine waste management options. Thermal disposal methods are recommended for highly contaminated sludge. Pyrolyzed sewage sludge generates biochar that can be used as a value-added agricultural product or as an alternative fuel. The biochar production itself carries the risk of emitting harmful compounds. Unfortunately, these important safety considerations are rarely addressed in the literature. This research investigates the mechanistic effects of the storage headspace-to-biochar volume ratio and stored biochar headspace ventilation on hazardous gas emissions. Five hazardous organic compounds were emitted by biochar. However, based on this initial proof-of-the-concept research, we could not derive conclusive trends for the effects of the headspace-to-biochar volume ratio or air exchanges in the biochar headspace. Further research, which is broader in scope (feedstock type, pyrolysis conditions), should be carried out. Nevertheless, caution should be exercised when designing biochar storage, aiming to lower the risk of occupational exposure to hazardous gas emissions. Monitoring air pollutants, tracking the highest permissible concentrations and workers’ exposure, and using personal protective equipment are recommended.