DOI: 10.1016/j.scitotenv.2019.136444
论文题名: Hydrophobicity of peat soils: Characterization of organic compound changes associated with heat-induced water repellency
作者: Wu Y. ; Zhang N. ; Slater G. ; Waddington J.M. ; de Lannoy C.-F.
刊名: Science of the Total Environment
ISSN: 489697
出版年: 2020
卷: 714 语种: 英语
英文关键词: Chemical characterization
; Feather moss
; GC–MS analysis
; Hydrophilicity
; Moisture content
; Wildfire
Scopus关键词: Climate change
; Degradation
; Ecosystems
; Fatty acids
; Fires
; Fourier transform infrared spectroscopy
; Gas chromatography
; Heating
; Hydrocarbons
; Hydrophilicity
; Hydrophobicity
; Mass spectrometry
; Moisture
; Peat
; Surface chemistry
; Wetlands
; Aliphatic hydrocarbons
; Chemical characterization
; Fatty acid contents
; Feather moss
; Gas chromatography-mass spectrometry
; Polycyclic compounds
; Short-chain molecules
; Wildfire
; Soils
; aliphatic hydrocarbon
; aromatic carboxylic acid
; carbohydrate
; lignin
; long chain fatty acid
; organic compound
; polycyclic hydrocarbon
; chemical composition
; gas chromatography
; hydrophobicity
; mass spectrometry
; moisture content
; moss
; organic compound
; peat soil
; soil chemistry
; wildfire
; Article
; chemical modification
; evaporation
; fatty acid analysis
; forest fire
; Fourier transform infrared spectroscopy
; geochemical analysis
; geochemistry
; heat treatment
; high temperature
; hydrophilicity
; hydrophobicity
; mass fragmentography
; moisture
; peatland
; priority journal
; scanning electron microscopy
; soil chemistry
; soil degradation
; soil property
; soil structure
; taiga
; Degradation
; Ecosystems
; Fatty Acids
; Fires
; Gas Chromatography
; Heating
; Water
; Wettability
; Bryophyta
英文摘要: Boreal peatlands provide critical global and regional ecosystem functions including climate regulation and nutrient and water retention. Wildfire represents the largest disturbance to these ecosystems. Peatland resilience depends greatly on the extent of post-fire peat soil hydrophobicity. Climate change is altering wildfire intensity and severity and consequently impacting post-fire peat soil chemistry and structure. However, research on fire-impacted peatlands has rarely considered the influence of peat soil chemistry and structure on peatland resilience. Here we characterized the geochemical and physical properties of natural peat soils under laboratory heating conditions. The general trend observed is that hydrophilic peat soils become hydrophobic under moderate heating and then become hydrophilic again after heating for longer, or at higher, temperatures. The loss of peat soil hydrophilicity initially occurs due to evaporative water loss (250 °C and 300 °C for <5 min). Gently but thoroughly dried peat soils (105 °C for 24 h) also show mass losses after heating, indicating the loss of organic compounds through thermal degradation. Gas chromatography-mass spectrometry (GC–MS) and Fourier transform infrared (FTIR) spectroscopy were used to characterize the chemistry of unburned and 300 °C burned peat soils, and various fatty acids, polycyclic compounds, saccharides, aromatic acids, short-chain molecules, lignin and carbohydrates were identified. We determined that the heat-induced degradation of polycyclic compounds and aliphatic hydrocarbons, especially fatty acids, caused dried, hydrophobic peat soils to become hydrophilic after only 20 min of heating at 300 °C. Furthermore, peat soils became hydrophilic more quickly (20 min vs 6 h) with an increase in heat from 250 °C to 300 °C. Minimal structural changes occurred, as characterized by BET and SEM analyses, confirming that surface chemistry, in particular fatty acid content, rather than structure govern changes in peat soil hydrophobicity. © 2020 Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/158352
Appears in Collections: 气候变化与战略
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作者单位: Department of Chemical Engineering, McMaster University, Hamilton, Ontario, Canada; School of Geography & Earth Sciences, McMaster University, Hamilton, Ontario, Canada
Recommended Citation:
Wu Y.,Zhang N.,Slater G.,et al. Hydrophobicity of peat soils: Characterization of organic compound changes associated with heat-induced water repellency[J]. Science of the Total Environment,2020-01-01,714