State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China.
State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
Environ Pollut. 2020 Jul;262:114266. doi: 10.1016/j.envpol.2020.114266. Epub 2020 Feb 29.
Humic-like substances (HULIS) are complex mixtures that are highly associated with brown carbon (BrC) and are important components of biomass burning (BB) emissions. In this study, we investigated the light absorption, emission factors (EFs), and amounts of HULIS emitted from the simulated burning of 27 types of regionally important rainforest biomass in Southeast Asia. We observed that HULIS had a high mass absorption efficiency at 365 nm (MAE), with an average value of 2.6 ± 0.83 m g C. HULIS emitted from BB accounted for 65% ± 13% of the amount of water-soluble organic carbon (WSOC) and 85% ± 10% of the light absorption of WSOC at 365 nm. The EFs of HULIS from BB averaged 2.3 ± 2.1 g kg fuel, and the burning of the four vegetation subtypes (herbaceous plants, shrubs, evergreen trees, and deciduous trees) exhibited different characteristics. The differences in EFs among the subtypes were likely due to differences in lignin content in the vegetation, the burning conditions, or other factors. The light absorption characteristics of HULIS were strongly associated with the EFs. The annual emissions (minimum-maximum) of HULIS from BB in this region in 2016 were 200-371 Gg. Furthermore, the emissions from January to April accounted for 99% of the total annual emissions of HULIS, which is likely the result of the burning activities during this season. The most significant emission regions were Cambodia, Burma, Thailand, and Laos. This study, which evaluated emissions of HULIS by simulating open BB, contributes to a better understanding of the light-absorbing properties and regional budgets of BrC in this region.
腐殖质类似物（HULIS）是与棕色碳（BrC）高度相关的复杂混合物，是生物质燃烧（BB）排放的重要组成部分。在这项研究中，我们调查了 27 种东南亚地区重要热带雨林生物质模拟燃烧过程中 HULIS 的光吸收、排放因子（EF）和排放量。我们观察到 HULIS 在 365nm 处具有高质量吸收效率（MAE），平均值为 2.6±0.83m g C。BB 排放的 HULIS 占水溶性有机碳（WSOC）总量的 65%±13%，占 WSOC 在 365nm 处光吸收的 85%±10%。BB 排放的 HULIS 的 EF 平均为 2.3±2.1g kg 燃料，四种植被亚型（草本植物、灌木、常绿树木和落叶树木）的燃烧表现出不同的特征。亚型之间 EF 的差异可能归因于植被中木质素含量、燃烧条件或其他因素的差异。HULIS 的光吸收特性与 EF 密切相关。2016 年该地区 BB 排放的 HULIS 年排放量（最小-最大）为 200-371Gg。此外，1 月至 4 月的排放量占 HULIS 年总排放量的 99%，这可能是该季节燃烧活动的结果。排放量最大的地区是柬埔寨、缅甸、泰国和老挝。本研究通过模拟开放式 BB 排放评估 HULIS 的排放，有助于更好地了解该地区 BrC 的光吸收特性和区域预算。
