Smoldering of crop residues emits a large amount of intermediate volatility organic compounds to the atmosphere

Hui Sun; Jinlong Wang; Wei Liu; Ling Ruan; Zhaomin Yang; Xueqi Ma; Xiaowen Chen; Li Xu; Lin Du; Qifan Liu; Kun Li

doi:10.1016/j.jhazmat.2026.141877

Smoldering of crop residues emits a large amount of intermediate volatility organic compounds to the atmosphere

J Hazard Mater. 2026 May 1:508:141877. doi: 10.1016/j.jhazmat.2026.141877. Epub 2026 Mar 26.

Authors

Hui Sun¹, Jinlong Wang², Wei Liu², Ling Ruan², Zhaomin Yang³, Xueqi Ma¹, Xiaowen Chen¹, Li Xu⁴, Lin Du⁵, Qifan Liu⁶, Kun Li⁷

Affiliations

¹ Qingdao Key Laboratory for Prevention and Control of Atmospheric Pollution in Coastal Cities, Environment Research Institute, Shandong University, Qingdao 266237, China.
² Department of Environmental Science and Engineering, State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei 230026, China.
³ Qingdao Key Laboratory for Prevention and Control of Atmospheric Pollution in Coastal Cities, Environment Research Institute, Shandong University, Qingdao 266237, China; Department of Chemistry, University of California, Irvine, Irvine, CA 92697, United States.
⁴ School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China.
⁵ Qingdao Key Laboratory for Prevention and Control of Atmospheric Pollution in Coastal Cities, Environment Research Institute, Shandong University, Qingdao 266237, China; School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China.
⁶ Department of Environmental Science and Engineering, State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei 230026, China; Beijing National Laboratory for Molecular Sciences (BNLMS), Beijing 100190, China. Electronic address: liuqifan@ustc.edu.cn.
⁷ Qingdao Key Laboratory for Prevention and Control of Atmospheric Pollution in Coastal Cities, Environment Research Institute, Shandong University, Qingdao 266237, China; Shandong Key Laboratory of Environmental Processes and Health, Shandong University, Qingdao 266237, China. Electronic address: kun.li@sdu.edu.cn.

PMID: 41916179
DOI: 10.1016/j.jhazmat.2026.141877

Abstract

Intermediate volatility organic compounds (IVOCs) released from biomass combustion serve as significant precursors for secondary organic aerosol (SOA). As a biomass fuel with distinctive usage characteristics in China, combustion of crop residues under smoldering conditions still lacks quantitative investigation. In this study, emissions from the smoldering combustion of three typical crop residues (corn, rice, and wheat straw) in China were investigated in controlled smoldering experiments, using a FUSION proton transfer reaction time-of-flight mass spectrometry (FUSION PTR-TOF-MS) for online high-resolution detection of non-methane organic gases (NMOGs). A total of 97 NMOGs were identified, with IVOCs exhibiting emission factors (EFs) significantly higher than those reported under flaming or flaming-smoldering mixed combustion conditions. The contribution of IVOCs to the secondary organic aerosol formation potential (SOAFP) ranged from 35.2% to 55.1%, underscoring their role as dominant precursors of SOA. Moreover, model-predicted toxicity probabilities of the emitted IVOCs indicated a non-negligible potential for adverse health effects, emphasizing the importance of addressing crop residue smoldering. These findings highlight the critical role of IVOCs emitted during the smoldering of crop residues and suggest that IVOC emissions should be explicitly considered in assessments of the atmospheric and health impacts of crop residue burning.

Keywords: Biomass burning; Crop residues; Emission factors; Intermediate volatility organic compounds; Smoldering.