Many consolidated sediments experience in situ gas generation from methanogenesis, corrosion, or radiolysis reactions and can retain bubbles for long periods. Particular interest is motivated by the retention and acute release of flammable hydrogen from nuclear legacy waste sludge. X‐ray computed tomography was employed to observe 0.07–10 mm bubble populations within 30–1112 Pa yield strength Mg(OH)₂ sediments. High rates of partial coalescence were observed among sub‐millimeter microvoids, forming extensive bubble networks which spanned the 32 mm field of view. Lattice Boltzmann and Monte Carlo modeling demonstrated these networks to be highly pervious to gas, with effective diffusivities for hydrogen of 3.7–12.5 × 10⁻⁵ m² s⁻¹. Continuous vessel‐spanning bubble networks, dynamic connectivity between ganglia of coalesced bubbles, Haines jumps, and composite diffusion through the gas and aqueous phase can account for enhanced gas migration over length‐scales of several meters, thus enabling chronic gas release from low‐intermediate strength sediments ( kPa) too strong for buoyant bubble ebullition and too weak for vertical channel formation. © 2018 The Authors. AIChE Journal published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers. AIChE J, 64: 4131–4147, 2018

中文翻译：

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通过固结软沉积物中的可渗透气泡网络增强气体迁移

许多固结的沉积物会因甲烷生成，腐蚀或放射分解反应而产生原位气体，并且会长时间保留气泡。保留和急性释放核废旧污泥中的可燃氢引起了人们的特别兴趣。X射线计算机断层摄影术用于观察屈服强度Mg（OH）₂沉积物在30-1112 Pa内的0.07-10 mm气泡数量。在亚毫米的微孔之间观察到较高的部分聚结率，形成了跨越32毫米视场的广泛的气泡网络。Lattice Boltzmann和蒙特卡洛模型证明这些网络对气体具有高度的渗透性，氢的有效扩散率为3.7–12.5×10 ^-5 m ² s ^-1。连续的跨容器气泡网络，聚结的气泡神经节之间的动态连通性，Haines跳跃以及通过气相和水相的复合扩散可以解释气体在几米长的尺度上的运移，从而实现了从中低层的长期气体释放强度沉积物（kPa）对于浮泡气泡太强而对于垂直通道形成来说太弱。©2018作者。Wiley Periodicals，Inc.代表美国化学工程师学会出版的AIChE Journal。AIChE J，64：4131–4147，2018