Methane Bubble Growth and Migration in Aquatic Sediments Observed by X-ray μCT.
Methane Bubble Growth and Migration in Aquatic Sediments Observed by X-ray μCT.
复制标题
X 射线μCT 观察水生沉积物中甲烷气泡的生长和迁移
DOI：
10.1021/acs.est.7b06061
复制
发表时间：
2015
影响因子：
11.4
通讯作者：
A. Lorke
中科院分区：
文献类型：
--
作者：
T. De Kock;J. Wilkinson;V. Cnudde;S. Xiao;C. Buchmann;D. Uteau;S. Peth;A. Lorke
甲烷气泡的形成和运移是水生沉积物生态地球化学碳循环的重要组成部分。为了更好地了解沉积物的机械性能如何影响气泡的生长和运输在淡水沉积物中，20天的实验室培养实验，使用均质天然粘土和沙子进行。利用μCT对甲烷气泡的高分辨率发展进行了表征。最初，微气泡（<0.1 mm）的毛细管侵入主导气泡形成，持续产气（粘土4天;砂8天），周围沉积物变形形成大气泡，导致两种沉积物中大孔隙连通性增强。在低剪切屈服强度的沉积物（<100 Pa）中，大气泡（>1 mm）的生长是可能的，其中过量的气体压力足以置换沉积物。在砂内较低的位置，较高的剪切屈服强度（>360 Pa）导致微泡占优势，其中所需的毛细管进入压力较低。增强气泡迁移，引发的控制减少静水头，观察到整个粘土柱，而在砂移动的气泡被限制在上部6厘米。所观察到的大孔隙网络是气泡运动和释放的主要途径。
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 μCT. Initially, capillary invasion by microbubbles (<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.
影响因子：
--
作者：
C. Algar;B. Boudreau;Mark A. Barry
通讯作者：
C. Algar;B. Boudreau;Mark A. Barry
泥浆中气泡的形态：微计算机断层扫描评估
DOI：
--
发表时间：
2005
期刊：
影响因子：
--
作者：
A. Reed;B. Boudreau;C. Algar;Y. Furukawa
通讯作者：
Y. Furukawa
沸腾过程中沉积物孔隙水交换和溶质释放
影响因子：
3
作者：
S. Klein
通讯作者：
S. Klein