Different behavior of uranium(VI) on two clay minerals: montmorillonite and kaolinite

Zhang, Bo; Gao, Bai; Ma, Wenjie; Wang, Shiqi; Qi, Wenbin; Wu, Junzhe; Wang, Rong; Zhou, Yujuan; Liu, Yuanyuan

doi:10.1007/s10967-023-09119-5

Cited by 4 publications

(2 citation statements)

References 33 publications

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“…77 The main difference between them is that montmorillonite is a typical expansive clay and its sheetlayer spacing can accommodate various cations as well as water molecules, while kaolinite is nonexpansive and its sheet-layer spacing can barely hold cations and water molecules. 78,79 The effects of clay type and content on CH 4 hydrate formation in the clay-silt slurries is illustrated in Figure 3. One can see that the induction time decreased with increasing the montmorillonite content (Figure 3a), indicating that it had a positive effect on promoting CH 4 hydrate nucleation.…”

Section: Effects Of Clay Type and Content On Ch 4 Hydrate Formationmentioning

confidence: 99%

Methane Hydrate Formation and Decomposition Process in Clay-Silt Slurries

Mu,

Lai,

et al. 2024

Energy Fuels

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The gas-hydrate-sediment-water multiphase flow is often involved in drilling and exploitation of natural gas hydrate (NGH) reservoirs in seabed due to its weak cementation; therefore, understanding hydrate formation and decomposition in sediment-contained slurries is important. In this work, CH 4 hydrate formation and decomposition in clay-silt slurries was explored, the effects of clay type and content, stirring rate, additives, experimental temperature, and pressure were systematically investigated. The presence of clay notably accelerated CH 4 hydrate formation in slurries, and the montmorillonite exhibited a more obvious promotion effect than kaolinite. As the stirring rate increased, the induction time and reaction time were shortened, while the gas consumption rate and water conversion increased. The addition of 500 ppm sodium dodecyl sulfate (SDS) and 1.0 wt % fulvic acid (FA) significantly reduced the induction time and increased hydrate formation rate. During the interaction of SDS and sediment, CH 4 hydrate formed in the slurries instantaneously. The CH 4 hydrate decomposition rate in slurries increased as the experimental temperature increased or the pressure decreased. The temperature had a limited impact on the decomposition time above freezing point, while it was significant below freezing point. The presence of clay notably decreased the CH 4 hydrate decomposition rate in slurries. Compared to the clay-free system, the ΔT d values (temperature decreased during hydrate decomposition) in the montmorillonite systems were decreased, while they were increased in the kaolinite systems. The findings provide valuable insights for the exploitation of marine NGH.

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Section: Effects Of Clay Type and Content On Ch 4 Hydrate Formationmentioning

confidence: 99%

Methane Hydrate Formation and Decomposition Process in Clay-Silt Slurries

Mu,

Lai,

et al. 2024

Energy Fuels

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“…There are hydrated cations, such as calcium or sodium, between the layers, which balance the negative charges of the layer [39,40]. This structure endows montmorillonite with a good swelling and ion exchange capacity, resulting in an excellent adsorption and removal efficiency of many cationic pollutants, including heavy metals [41][42][43][44].…”

Section: Introductionmentioning

confidence: 99%

Influence of Sulfate and Nitrate for Lanthanum (III) Adsorption on Bentonite: Implications for Rare Earth Wastewater Disposal

Zhou,

Wan,

et al. 2024

Minerals

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The direct discharge of rare earth wastewater causes the waste of resources and heavy metal pollution. This paper compared the adsorption behaviors of lanthanide ions on bentonite under sulfate and nitrate systems by examining the factors affecting the adsorption, such as adsorption time, pH, background electrolyte concentration, and initial rare earth ion concentration. It was shown that the sulfate system was more favorable for the adsorption of rare earth ions on the bentonite surface. The maximum adsorption capacity in the sulfate system was about 1.7 times that in the nitrate system. In contrast, the adsorption under the nitrate system was more sensitive to the changes in pH and background electrolyte concentration. The adsorption processes under both systems are spontaneous physical adsorption processes (ΔGθ are from −27.64 to −31.48 kJ/mol), and both are endothermic (ΔHθ are 10.38 kJ/mol for the nitrate and 7.53 kJ/mol for the sulfate) and entropy-increasing (ΔSθ are 61.54 J/mol for the nitrate and 76.24 J∙mol−1 for the sulfate) processes. This study helps to provide information about the optimizing process parameters for the adsorption treatment of rare earth wastewater using bentonite.

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