Distribution of environmentally persistent free radicals in size-segregated PMs emitted from residential biomass fuel combustion

Jinfeng Zhao; Lin Shi; Jianwu Shi; Hao Li; Di Lang; Zhuo Wei; Shunling Li; Bo Pan

doi:10.1016/j.jhazmat.2023.130956

Distribution of environmentally persistent free radicals in size-segregated PMs emitted from residential biomass fuel combustion

J Hazard Mater. 2023 May 5:449:130956. doi: 10.1016/j.jhazmat.2023.130956. Epub 2023 Feb 6.

Authors

Jinfeng Zhao¹, Lin Shi², Jianwu Shi¹, Hao Li¹, Di Lang¹, Zhuo Wei¹, Shunling Li¹, Bo Pan³

Affiliations

¹ Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming 650500, Yunnan, China.
² Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming 650500, Yunnan, China; Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection, College of Resources and Environment, Linyi University, Linyi 276005, China.
³ Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming 650500, Yunnan, China. Electronic address: panbocai@gmail.com.

PMID: 36812726
DOI: 10.1016/j.jhazmat.2023.130956

Abstract

Environmentally persistent free radicals (EPFRs) are considered as an emerging pollutant due to their potential environmental risks, but the distribution characteristics of particulate matters (PMs)-EPFRs from residential combustion source are poorly understood. In this study, biomass (corn straw, rice straw, pine and jujube wood) combustion was studied in lab-controlled experiments. More than 80% of PM-EPFRs were distributed in PMs with aerodynamic diameter (d_ae) ≤ 2.1 µm, and their concentration in fine PMs was about 10 times that in coarse PM (2.1 µm ≤ d_ae ≤ 10 µm). The detected EPFRs were carbon-centered free radicals adjacent to oxygen atoms or a mixture of oxygen- and carbon-centered radicals. The concentrations of EPFRs in coarse and fine PMs were positively correlated with char-EC, but the EPFRs in fine PMs exhibited a negative correlation with soot-EC (p < 0.05). The increase of PM-EPFRs signals with the increased dilution ratio during pine wood combustion was more significant than that from rice straw, which may be resulted from the interactions between the condensable volatiles and the transition metals. Our study provides useful information for better understanding the formation of combustion-derived PM-EPFRs, and will be instructive for its purposeful emissions control.

Keywords: Dilution ratio; EPFRs; Generation; Particle size distributions; Solid fuel.