Keywords: biomass burning, aerosol, isotopic fractionation.
Biomass burning is a major contributor to atmospheric aerosols, releasing a variety of particles and gases that have significant environmental impacts. These aerosols not only affect local and regional air quality but also can be transported globally, influencing climate and atmospheric conditions in distant areas. This study investigates the aerosols produced from 17 different wood species and coal, focusing on their isotopic signatures of total carbon, elemental carbon, and organic carbon at varying combustion temperatures. The experimental setup was designed to replicate typical domestic heating practices in Lithuania during the winter months. Our findings reveal a wide range of isotopic variations in the carbon isotopes (δ13C) across the biomass fuels used in the burning experiments. Lower temperature combustion (below 350 °C) showed more diverse isotopic signatures compared to higher temperature stages (350 °C and 650 °C). Notably, distinct isotopic patterns emerged between C3 and C4 plants, with C4 species like corn exhibiting less negative δ13C values (-12‰), whereas C3 species, such as willow and oak, presented more negative values (-29‰ to -31‰). Elemental carbon (EC) consistently displayed more negative δ13C values compared to total carbon (TC) across most plant species, suggesting isotopic fractionation during EC formation. Additionally, the fractionation factor (ε) analysis revealed that, while most biomass materials showed ε values close to zero (indicating minimal fractionation), coal displayed unique isotopic behaviour with noticeably higher positive ε values. Overall, our study underscores the distinct isotopic signatures of different biomass fuels and coal, contributing to a deeper understanding of biomass burning aerosols and their environmental effects.