Optical properties and oxidative potential of water- and alkaline-soluble brown carbon in smoke particles emitted from laboratory simulated biomass burning

Fan, Xingjun; Li, Meiju; Cao, Tao; Cheng, Chongchong; Li, Feiyue; Xie, Yue; Wei, Siye; Song, Jianzhong; Peng, Ping’an

doi:10.1016/j.atmosenv.2018.09.025

Cited by 53 publications

(38 citation statements)

References 81 publications

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“…Taken together, it can be concluded that the protein-like substances were susceptible fluorophores, which were primarily oxidized before the longer-wavelength fulvic-like substances. This, however, is in contrast with the results from the dark OH radical oxidation of BB BrC reported in our recent study (Fan et al, 2019), suggesting that the fluorophores within the BrC oxidized by OH in the aqueous phase and those by O 3 in the particle phase are different. The main changes in the FTIR spectra of the BB BrC upon O 3 aging are displayed in the range 1800-1000 cm −1 (Fig.…”

Section: D-cos Combined With Fluorescence and Ftir Spectracontrasting

confidence: 99%

“…Furthermore, the O 3 aging mechanism of BB BrC is explored using EEM combined with a parallel factor analysis (PARAFAC) and a two-dimensional correlation analysis (2D-COS) applied on the synchronous fluorescence spectra and FTIR. These approaches have allowed us to investigate the levels and types of independent underlying fluorophores of BrC (Chen et al, 2016b;Fan et al, 2019) and explore the dynamic spectral behavior of chromophores and molecular structures of BrC (Fan et al, 2019;Duarte et al, 2015). Our results have great importance in terms of furthering source apportionment of atmospheric BrC and of improving the accuracy of predicting their effects in atmospheric environments and on climate change.…”

Section: Introductionmentioning

confidence: 89%

“…Recently, primary BB BrC has been widely studied, which has provided deep insights into its BB source-dependent chemical and optical properties (Fan et al, 2016(Fan et al, , 2018Park and Yu, 2016). Moreover, both laboratory and field studies have demonstrated that atmospheric aging processes will lead to a transformation of the chemical composition and optical properties of BB BrC once it is emitted into the atmosphere (Fan et al, 2019;Pillar et al, 2014Pillar et al, , 2015Pillar et al, , 2017Saleh et al, 2013;Schnitzler and Abbatt, 2018;Sumlin et al, 2017;Wong et al, 2017Wong et al, , 2019Zhong and Jang, 2014). The relevant processes mainly occur in either the atmospheric aqueous phase (Fan et al, 2019;Wong et al, 2017Wong et al, , 2019Zhao et al, 2015), gas phase (Schnitzler and Abbatt, 2018;Sumlin et al, 2017; Zhong and Jang, 2014), or air-particle interface (Pillar-Little and Guzma, 2018, and references therein) with homogeneous or heterogeneous oxidation.…”

Section: Introductionmentioning

confidence: 99%

“…The results suggest that the chromophoric characteristics of aged BrC are highly variable across different precursors and oxidation conditions. Many recent laboratory simulation studies have also tentatively explored the evolution and oxidation mechanisms of water-soluble BB BrC in the aqueous phase with or without light (Fan et al, 2019;Wong et al, 2017Wong et al, , 2019. These studies have observed that BB BrC undergoes both enhancement and bleaching, but a significant bleaching of BrC dominantly occurs over a long aging time.…”

Section: Introductionmentioning

confidence: 99%

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The evolutionary behavior of chromophoric brown carbon during ozone aging of fine particles from biomass burning

Fan

Cao

et al. 2020

Atmos. Chem. Phys.

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Abstract. Biomass burning (BB) emits large amounts of brown carbon (BrC); however, the evolutionary behavior of BrC in BB emissions (BB BrC) resulting from complex atmospheric processes is poorly understood. In this study, the transformation of contents and the chromophoric characteristics of BrC in smoke particles emitted by the burning of rice straw (RS), corn straw (CS), and pinewood (PW) under O3 aging are investigated. The O3 aging induced the reduction of light absorption and fluorescence for the BB BrC, suggesting the decomposition of chromophores and fluorophores. These changes were accompanied by a decrease in aromaticity, average molecular weight, and the light absorption capacity for the chromophores, as well as an increase in humification for the fluorophores. The excitation emission matrix combined with a parallel factor analysis revealed that protein-like components (C3) were predominantly decomposed by O3 aging, while the relative distribution of a humic-like component with highly oxygenated chromophores (C4) gradually increased. In general, the humic-like substances (C1 + C2 + C4) were transformed to be the most abundant fluorophores for all the BB BrC samples, which accounted for 84 %–87 % of the total fluorophores in final O3-aged BB BrC. Two-dimensional correlation spectroscopy (2D-COS) was performed on the synchronous fluorescence, which suggested that the RS and CS BrC exhibits the same susceptible fluorophores changes upon O3 aging. It showed that O3 firstly reacted with protein-like fractions (263–289 nm) and then with fulvic-like fractions (333–340 nm). In comparison, the changing sequence of susceptible fluorophores in the PW BrC to O3 was in the order of fulvic-like fluorophores with shorter wavelengths (309 nm), protein-like fluorophores (276 nm), and fulvic-like fluorophores with longer wavelengths (358 nm). The 2D-FTIR-COS (2D-COS combined with FTIR) analysis showed conjugated C=O and aromatic C=C and C=O groups were the most susceptible functional groups to O3 aging for all BB BrC. Moreover, it also revealed a consistent sequential change, which is in the order of aromatic OH; conjugated C=O groups and aromatic C=O; aromatic COO−; and finally lignin-derived C–C, C–H, and C–O groups. Our results provide new insights into the evolutionary behavior of the chromophoric and fluorescent properties of BB BrC during O3 aging, which are of great significance for better understanding the heterogeneous oxidation pathways of BB-derived BrC in the atmospheric environment.

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Section: D-cos Combined With Fluorescence and Ftir Spectracontrasting

confidence: 99%

Section: Introductionmentioning

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The evolutionary behavior of chromophoric brown carbon during ozone aging of fine particles from biomass burning

Fan

Cao

et al. 2020

Atmos. Chem. Phys.

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“…The light absorption capabilities of different BBOA fractions are compared in Figure 6. The estimated MAE 365 values of straw burning-generated BrC in this study are comparable to those reported in previous studies (Fan et al, 2018;Xie et al, 2017). The MAE of WISOC are higher than water-soluble BBOA (WSOC and HULIS) among the measured wavelength ranges for both corn and wheat burning aerosols.…”

Section: Light Absorption Of Bboasupporting

confidence: 87%

Chemical composition and light absorption of carbonaceous aerosols emitted from crop residue burning: Influence of combustion efficiency

Wang¹,

Hu²,

Xu³

et al. 2020

Preprint

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Abstract. Biomass burning is one of the major sources of carbonaceous aerosols, which affects air quality, radiation budget and human health. Field straw residue burning is a widespread type of biomass burning in Asia, while its emissions are poorly understood compared with the wood burning emissions. In this study, lab-controlled straw (wheat and corn) burning experiments were designed to investigate the emission factors and light absorption properties of different biomass burning organic aerosol (BBOA) fractions, including water soluble organic carbon (WSOC), humic-like substances (HULIS) and water insoluble organic carbon (WISOC). The influences of biofuel moisture content and combustion efficiency on emissions are comprehensively discussed. The emission factors of PM2.5, OC and EC were 9.3 ± 3.4, 4.6 ± 1.9 and 0.21 ± 0.07 g/kg for corn burning and 8.7 ± 5.0, 3.9 ± 2.8 and 0.22 ± 0.05 g/kg for wheat burning, generally lower than wood or forest burning emissions. Though the mass contribution of WISOC among OC (32 %–43 %) was lower than WSOC, the light absorption contribution of WISOC (57 %–84 % @ 300–400 nm) surpassed WSOC due to the higher mass absorption eﬃciency (MAE) of WISOC. The results suggested that BBOA light absorption would be largely underestimated if only considering the water soluble fractions. However, the light absorption of WSOC among near-UV ranges, occupying 39 %–43 % of the total extracted OC absorption at 300 nm, cannot be negligible due to the sharper increase of absorption towards shorter wavelength compared with WISOC. HULIS were the major light absorption contributors among WSOC, due to the higher MAE of HULIS than other high-polarity WSOC components. The emission levels and light absorption of BBOA were largely influenced by the burning conditions, indicated by modified combustion efficiency (MCE) calculated by measured CO and CO2 in this work. The emission factors of PM2.5, OC, WSOC, HULIS and organic acids were enhanced under lower-MCE conditions or during higher-moisture straw burning experiments. Light absorption coefficients of BBOA at 365 nm were also observed higher under lower-MCE conditions, which was mainly due to the elevated mass emission factors. Our results suggested that the influence of varied combustion efficiency on particle emissions could surpass the differences caused by different types of biofuels. Thus, the burning efficiency or conditions should be taken into consideration when estimating the influence of biomass burning. In addition, we observed that the K+ / OC and Cl− / OC ratios increased under higher-MCE conditions due to the enhancement of released potassium and chlorine under higher fire temperatures during flaming combustion. This indicates that potassium ion, as a commonly used biomass burning tracer, may lead to estimation uncertainty if without considering the burning conditions.

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Plant and algal toxicity of persistent free radicals and reactive oxygen species generated by heating anthracene-contaminated soils from 100 to 600 °C

et al. 2021

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Persistent free radicals (PFRs) are emerging contaminants of increasing concern, yet their formation, fate, toxicity and health risk are poorly known. Thermal treatment, a common remediation technique to clean industrial soils, induces the formation of PFRs, which could paradoxically increase soil toxicity, contrary to the original objective of remediation. Actually, there is little knowledge on the formation and toxicity of PFRs in soils contaminated by polycyclic aromatic hydrocarbons (PAHs). Here we studied the generation of PFRs of soils spiked with anthracene and heated 1 h from 100 to 600 °C, using electron paramagnetic resonance. We also investigated the formation of reactive oxygen species (ROS), e.g. superoxide radical (O 2•− ), hydrogen peroxide (H 2 O 2 ) and hydroxyl radical (•OH), in the aqueous phase of thermal-treated soil, and the impact of heating on soil oxidative potential, wheat growth and green algae activity. Results showed that PFRs, ROS, soil oxidative potential, plant toxicity and algal toxicity show a similar trend with an increase from 100 to 300 °C, followed by a decrease to 600 °C. Scavenger trapping tests reveal that algal toxicity is mainly due to the generation of O 2•− , •OH and H 2 O 2 induced by anthracene-PFRs and that anthracene and anthracene-PFRs have negligible direct algal toxicity. Overall, our findings reveal the unintended formation of toxic compounds peaking at 300 °C during the thermal remediation of PAHcontaminated soils. These results should help to assess the environmental risk of thermally treated PAH-contaminated soils.

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Optical properties and oxidative potential of water- and alkaline-soluble brown carbon in smoke particles emitted from laboratory simulated biomass burning

Cited by 53 publications

References 81 publications

The evolutionary behavior of chromophoric brown carbon during ozone aging of fine particles from biomass burning

The evolutionary behavior of chromophoric brown carbon during ozone aging of fine particles from biomass burning

Chemical composition and light absorption of carbonaceous aerosols emitted from crop residue burning: Influence of combustion efficiency

Plant and algal toxicity of persistent free radicals and reactive oxygen species generated by heating anthracene-contaminated soils from 100 to 600 °C

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