Advanced search
1 file | 2.71 MB

Methane bubble growth and migration in aquatic sediments observed by X-ray μCT

Author
Organization
Abstract
Methane bubble formation and transport is an important component of biogeochemical carbon cycling in aquatic sediments. To improve understanding of how sediment mechanical properties influence bubble growth and transport in freshwater sediments, a 20-day laboratory incubation experiment using homogenized natural clay and sand was performed. Methane bubble development at high resolution was characterized by mu CT. Initially, capillary invasion by micro bubbles (<0.1 mm) dominated bubble formation, with continued gas production (4 days for clay; 8 days for sand), large bubbles formed by deforming the surrounding sediment, leading to enhanced of macropore connectivity in both sediments. Growth of large bubbles (>1 mm) was possible in low shear yield strength sediments (<100 Pa), where excess gas pressure was sufficient to displace the sediment. Lower within the sand, higher shear yield strength (>360 Pa) resulted in a predominance of microbubbles where the required capillary entry pressure was low. Enhanced bubble migration, triggered by a controlled reduction in hydrostatic head, was observed throughout the clay column, while in sand mobile bubbles were restricted to the upper 6 cm. The observed macropore network was the dominant path for bubble movement and release in both sediments.
Keywords
LARGE GAS-BUBBLES, GRAINED SEDIMENTS, SOLUTE TRANSPORT, SOFT SEDIMENTS, WATER-FLOW, EBULLITION, SOILS, QUANTIFICATION, MACROPORES, MICROTOMOGRAPHY

Downloads

  • (...).pdf
    • full text
    • |
    • UGent only
    • |
    • PDF
    • |
    • 2.71 MB

Citation

Please use this url to cite or link to this publication:

Chicago
Liu, Liu, Tim De Kock, Jeremy Wilkinson, Veerle Cnudde, Shangbin Xiao, Christian Buchmann, Daniel Uteau, Stephan Peth, and Andreas Lorke. 2018. “Methane Bubble Growth and Migration in Aquatic Sediments Observed by X-ray μCT.” Environmental Science & Technology 52 (4): 2007–2015.
APA
Liu, Liu, De Kock, T., Wilkinson, J., Cnudde, V., Xiao, S., Buchmann, C., Uteau, D., et al. (2018). Methane bubble growth and migration in aquatic sediments observed by X-ray μCT. ENVIRONMENTAL SCIENCE & TECHNOLOGY, 52(4), 2007–2015.
Vancouver
1.
Liu L, De Kock T, Wilkinson J, Cnudde V, Xiao S, Buchmann C, et al. Methane bubble growth and migration in aquatic sediments observed by X-ray μCT. ENVIRONMENTAL SCIENCE & TECHNOLOGY. 2018;52(4):2007–15.
MLA
Liu, Liu, Tim De Kock, Jeremy Wilkinson, et al. “Methane Bubble Growth and Migration in Aquatic Sediments Observed by X-ray μCT.” ENVIRONMENTAL SCIENCE & TECHNOLOGY 52.4 (2018): 2007–2015. Print.
@article{8551502,
  abstract     = {Methane bubble formation and transport is an important component of biogeochemical carbon cycling in aquatic sediments. To improve understanding of how sediment mechanical properties influence bubble growth and transport in freshwater sediments, a 20-day laboratory incubation experiment using homogenized natural clay and sand was performed. Methane bubble development at high resolution was characterized by mu CT. Initially, capillary invasion by micro bubbles ({\textlangle}0.1 mm) dominated bubble formation, with continued gas production (4 days for clay; 8 days for sand), large bubbles formed by deforming the surrounding sediment, leading to enhanced of macropore connectivity in both sediments. Growth of large bubbles ({\textrangle}1 mm) was possible in low shear yield strength sediments ({\textlangle}100 Pa), where excess gas pressure was sufficient to displace the sediment. Lower within the sand, higher shear yield strength ({\textrangle}360 Pa) resulted in a predominance of microbubbles where the required capillary entry pressure was low. Enhanced bubble migration, triggered by a controlled reduction in hydrostatic head, was observed throughout the clay column, while in sand mobile bubbles were restricted to the upper 6 cm. The observed macropore network was the dominant path for bubble movement and release in both sediments.},
  author       = {Liu, Liu and De Kock, Tim and Wilkinson, Jeremy and Cnudde, Veerle and Xiao, Shangbin and Buchmann, Christian and Uteau, Daniel and Peth, Stephan and Lorke, Andreas},
  issn         = {0013-936X},
  journal      = {ENVIRONMENTAL SCIENCE \& TECHNOLOGY},
  language     = {eng},
  number       = {4},
  pages        = {2007--2015},
  title        = {Methane bubble growth and migration in aquatic sediments observed by X-ray \ensuremath{\mu}CT},
  url          = {http://dx.doi.org/10.1021/acs.est.7b06061},
  volume       = {52},
  year         = {2018},
}

Altmetric
View in Altmetric
Web of Science
Times cited: