Burn Intensity Drives the Alteration of Phenolic Lignin to (Poly) Aromatic Hydrocarbons as Revealed by Pyrolysis Gas Chromatography–Mass Spectrometry (Py-GC/MS),Environmental Science & Technology

当前位置： X-MOL 学术 › Environ. Sci. Technol. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Burn Intensity Drives the Alteration of Phenolic Lignin to (Poly) Aromatic Hydrocarbons as Revealed by Pyrolysis Gas Chromatography–Mass Spectrometry (Py-GC/MS)
Environmental Science & Technology ( IF 10.8 ) Pub Date : 2022-08-10 , DOI: 10.1021/acs.est.2c00426
Huan Chen ₁ , Jun-Jian Wang _{2,

3} , Pei-Jia Ku ₄ , Martin Tsz-Ki Tsui ₅ , Rebecca B Abney ₆ , Asmeret Asefaw Berhe ₇ , Qiang Zhang _{2,

3} , Sarah D Burton ₈ , Randy A Dahlgren ₉ , Alex T Chow ₁

Affiliation

Biogeochemistry & Environmental Quality Research Group, Clemson University, Georgetown, South Carolina 29442, United States.
Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.
School of Life Sciences, State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong SAR, China.
D.B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, Georgia 30602, United States.
Department of Life and Environmental Sciences, University of California, Merced, California 95343, United States.
Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States.
Department of Land, Air, and Water Resources, University of California, Davis, California 95616, United States.

High-intensity wildfires alter the chemical composition of organic matter, which is expected to be distinctly different from low-intensity prescribed fires. Herein, we used pyrolysis gas chromatography/mass spectrometry (Py-GC/MS), in conjunction with solid-state ¹³C nuclear magnetic resonance (NMR) and Fourier transform infrared (FT-IR) spectroscopy, to assess chemical alterations from three wildfires and a long-term frequent prescribed fire site. Our results showed that black ash formed under moderate intensity burns contained less aromatic (ArH), polyaromatic hydrocarbon (PAH), and nitrogen-containing compounds (Ntg) but more lignin (LgC) and phenol compounds (PhC), compared to white ash formed under high intensity burns. Both ¹³C NMR and FT-IR confirmed a higher relative percentage of carboxyl carbon in white ash, indicating the potential for higher water solubility and more mobile carbon, relative to black ash. Compared to wildfires, ash from low-intensity prescribed fire contained less ArH, PAH, and Ntg and more LgC and PhC. Controlled laboratory burning trials indicated that organic matter alteration was sensitive to the burn temperature, but not related to the fuel type (pine vs fir) nor oxygen absence/presence at high burn temperatures. This study concludes that higher burn temperatures resulted in higher (poly)aromatic carbon/nitrogen and lower lignin/phenol compounds.

中文翻译：

热解气相色谱-质谱 (Py-GC/MS) 揭示燃烧强度推动酚类木质素向（多）芳香烃的转变

高强度野火改变了有机物的化学成分，预计这与低强度规定的火灾明显不同。在这里，我们使用热解气相色谱/质谱 (Py-GC/MS) 结合固态¹³ C 核磁共振 (NMR) 和傅里叶变换红外 (FT-IR) 光谱来评估三场野火的化学变化和一个长期频繁的规定火灾地点。我们的研究结果表明，与形成的白灰相比，在中等强度燃烧下形成的黑灰含有较少的芳香族 (ArH)、多环芳烃 (PAH) 和含氮化合物 (Ntg)，但含有较多的木质素 (LgC) 和酚类化合物 (PhC)在高强度烧伤下。两个¹³C NMR 和 FT-IR 证实了白灰中羧基碳的相对百分比较高，表明相对于黑灰，具有更高水溶性和更多移动碳的潜力。与野火相比，低强度规定火灾产生的灰烬含有较少的 ArH、PAH 和 Ntg，而含有较多的 LgC 和 PhC。受控的实验室燃烧试验表明，有机物的变化对燃烧温度很敏感，但与燃料类型（松树与冷杉）无关，也与高燃烧温度下的氧气缺乏/存在无关。该研究得出结论，较高的燃烧温度导致较高的（多）芳香族碳/氮和较低的木质素/酚类化合物。

更新日期：2022-08-10

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11