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The lithological features of sediments control the heterogeneity in permeability. This study numerically investigates the effect of lithological rhythm of a confined hydrate reservoir on gas production for warm water injection scenarios. The investigated lithological rhythm structures range from simple rhythms to complex composite rhythms. The depressurization in multiple wells causes significant gas production. However, the decrease in pressure gradient constrained the production of gas and water. The warm water injection enhances the production of gas and water with various lag times, though it results in a low energy efficiency. The positive and reverse rhythms have similar energy efficiencies. The gas and water production rate slightly decrease with the increase in the permeability contrast. The maximum gas production rate increases with the increase in number of composite rhythmic layers. However, the water production changes only slightly. The rhythm structures significantly affect the gas and water production rates. A high permeability region in the bottom part of the reservoir is conducive to warm water breakthrough. However, it is unfavorable for the dissociation of remnant hydrate in low permeability regions. Moreover, the results show that the rhythm structures also affect the gas productivity of each rhythmic layer. The results presented in this study help us understand the effect of complex and real rhythm structures on the gas production performance and the dynamic evolution of hydrate dissociation zone.
Guangrong Jin; Jie Liu; Lihua Liu; Haizhen Zhai; DaiDai Wu; Jie Su; Tianfu Xu. Effect of lithological rhythm of a confined hydrate reservoir on gas production performance using water flooding in five-spot vertical well system. Journal of Natural Gas Science and Engineering 2021, 92, 104019 .
AMA StyleGuangrong Jin, Jie Liu, Lihua Liu, Haizhen Zhai, DaiDai Wu, Jie Su, Tianfu Xu. Effect of lithological rhythm of a confined hydrate reservoir on gas production performance using water flooding in five-spot vertical well system. Journal of Natural Gas Science and Engineering. 2021; 92 ():104019.
Chicago/Turabian StyleGuangrong Jin; Jie Liu; Lihua Liu; Haizhen Zhai; DaiDai Wu; Jie Su; Tianfu Xu. 2021. "Effect of lithological rhythm of a confined hydrate reservoir on gas production performance using water flooding in five-spot vertical well system." Journal of Natural Gas Science and Engineering 92, no. : 104019.
The Haima cold seep, which is one of the two active cold seeps in the South China Sea, is known for its great ecological importance. The seep bivalves are assumed to depend mainly on their bacterial symbiosis for survival and growth. However, information on the bacterial diversity, composition, and putative function of gill-associated of dominant dwelling animals in Haima cold seep remain elusive. Herein, we adopted a high-throughput sequencing of 16S rRNA gene amplicons, and function prediction methods (Functional Annotation of Prokaryotic Taxa (FAPROTAX) and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICURUSTs)) to purposely illustrate the taxonomic and phylogenetic diversity, composition, and putative functions of the symbionts in bathymodiolin mussel Gigantidas haimaensis (Bivalvia: Mytilidae: Gigantidas) and vesicomyid clam Archivesica marissinica (Bivalvia: Glossoidea: Vesicomyidae). The predominant microbes of both species were Proteobacteria and Gammaproteobacteria on the phylum and class level, respectively. The taxonomic and phylogenetic diversity of gill microbial communities in G. haimaensis were significantly different from those in A. marissinica (p < 0.05). Nine functional groups, including seven carbon-related biogeochemical groups, were identified through the FAPROTAX analysis. However, the most dominant groups for G. haimaensis and A. marissinica were both chemoheterotrophic. G. haimaensis and A. marissinica shared many pathways, however, 16 obtained Kyoto Encyclopedia of Genes and Genomes (KEGG) orthologous groups (42.11%) significantly differed between the two species (p < 0.05). These findings would provide insight into the functions of microbes in the element cycling and energy flow as well as the host-symbiont relationship of bivalves in the Haima cold seep environment.
Juan Ling; Hongxiang Guan; Lihua Liu; Jun Tao; Jie Li; Junde Dong; Si Zhang. The Diversity, Composition, and Putative Functions of Gill-Associated Bacteria of Bathymodiolin Mussel and Vesicomyid Clam from Haima Cold Seep, South China Sea. Microorganisms 2020, 8, 1699 .
AMA StyleJuan Ling, Hongxiang Guan, Lihua Liu, Jun Tao, Jie Li, Junde Dong, Si Zhang. The Diversity, Composition, and Putative Functions of Gill-Associated Bacteria of Bathymodiolin Mussel and Vesicomyid Clam from Haima Cold Seep, South China Sea. Microorganisms. 2020; 8 (11):1699.
Chicago/Turabian StyleJuan Ling; Hongxiang Guan; Lihua Liu; Jun Tao; Jie Li; Junde Dong; Si Zhang. 2020. "The Diversity, Composition, and Putative Functions of Gill-Associated Bacteria of Bathymodiolin Mussel and Vesicomyid Clam from Haima Cold Seep, South China Sea." Microorganisms 8, no. 11: 1699.
The lithological characteristics of subsurface formations control the variations in the permeability. Herein, the effect of lithological rhythm on gas production was numerically investigated for depressurization applied in a confined hydrate reservoir. The lithological rhythm structures from simple uniform, positive, and reserve rhythms to complex composite rhythms were designed. The water-to-gas ratio showed that economic feasibility of all rhythms varied with the expansion of the hydrate dissociation region. The depth of high permeability region affected the hydrate dissociation and temperature recovery. Therefore, the gas production rate of positive rhythm was higher than that of the uniform and reverse rhythms, while the reverse rhythm was economically more suitable in the later stages of the production. Furthermore, the gas and water production rates decreased with the increase in the permeability contrast. The number of composite rhythmic layers negligibly affected the gas production rate, while it significantly affected the hydrate saturation distribution, indicating an increasing hydraulic connectivity in the lateral direction that may lead to water breakthrough. Moreover, the rhythmic structures significantly affected the gas production rate and the economic feasibility, and controlled the developed depth of high hydraulic connectivity. Therefore, minor and large seepage pathways could form in a complex rhythm reservoir.
Guangrong Jin; Jie Liu; Lihua Liu; Haizhen Zhai; DaiDai Wu; Tianfu Xu. Effect of lithological rhythm on gas production performance via depressurization through a vertical well in a confined hydrate reservoir. Marine and Petroleum Geology 2020, 122, 104696 .
AMA StyleGuangrong Jin, Jie Liu, Lihua Liu, Haizhen Zhai, DaiDai Wu, Tianfu Xu. Effect of lithological rhythm on gas production performance via depressurization through a vertical well in a confined hydrate reservoir. Marine and Petroleum Geology. 2020; 122 ():104696.
Chicago/Turabian StyleGuangrong Jin; Jie Liu; Lihua Liu; Haizhen Zhai; DaiDai Wu; Tianfu Xu. 2020. "Effect of lithological rhythm on gas production performance via depressurization through a vertical well in a confined hydrate reservoir." Marine and Petroleum Geology 122, no. : 104696.
Anaerobic oxidation of methane (AOM) is a common biochemical process in the ocean and it plays an important role in global climate change, elemental circulation, and atmospheric evolution over geological time. In this paper, we analyzed of δ34S, Fe, Mn, Ca/Ti, and Sr/Ti ratios, and the date of carbon and sulfur from the site SH3 of Shenhu area. Result showed that (1) 0-6 mbsf (meter blow the sea floor) was mainly affected by OSR (anaerobic oxidation of organic matters) and 7-15 mbsf was a paleo-SMTZ (sulfate-methane transition zone) position. The modern SMTZ was mainly distributed at 19-25 mbsf. The barium sulfate precipitation above the modern SMTZ indicating that the current methane leakage was stable and lasted longer during geological history. (2) By studying the change of magnetic and the different carbonate minerals, results showed that there were two AOM stages. During the early stage, Fe2+ were mainly produced by sulfide abiotic reductive dissolution. During the later stage, Fe2+ were mainly produced by the metal-AOM. (3) Study of the mineral characteristics of the paleo-SMTZ and the modern SMTZ showed that the modern SMTZ carbonate minerals were mainly low-Mg calcite and aragonite, while the paleo-SMTZ carbon minerals were mainly high Mg minerals. The reason for this difference is that the modern SMTZ layer was only experienced the first stage of anaerobic oxidation of methane. In the paleo-SMTZ layer, it has experienced two stage of anaerobic oxidation of methane. During the last stage of metal-AOM, the low Mg carbonate minerals were converted into high Mg carbonate minerals. This research confirms the presence of metal-driven methane anaerobic oxidation at the bottom of sulfate-driven methane anaerobic oxidation and during the metal-driven methane anaerobic oxidation, methane and metal oxides or hydroxides would couple to convert the in situ metal oxides or hydroxides into metal ions, meanwhile the phosphorus adsorbed on the surface of the metal oxides is released into adjacent pore water, and convert to new P-bearing minerals under suitable conditions.
Rui Xie; DaiDai Wu; Jie Liu; Tiantian Sun; Lihua Liu; Nengyou Wu. Geochemical Evidence of Metal-Driven Anaerobic Oxidation of Methane in the Shenhu Area, the South China Sea. International Journal of Environmental Research and Public Health 2019, 16, 3559 .
AMA StyleRui Xie, DaiDai Wu, Jie Liu, Tiantian Sun, Lihua Liu, Nengyou Wu. Geochemical Evidence of Metal-Driven Anaerobic Oxidation of Methane in the Shenhu Area, the South China Sea. International Journal of Environmental Research and Public Health. 2019; 16 (19):3559.
Chicago/Turabian StyleRui Xie; DaiDai Wu; Jie Liu; Tiantian Sun; Lihua Liu; Nengyou Wu. 2019. "Geochemical Evidence of Metal-Driven Anaerobic Oxidation of Methane in the Shenhu Area, the South China Sea." International Journal of Environmental Research and Public Health 16, no. 19: 3559.
Persistent organic pollutants (POPs) monitoring and management in typical semi-enclosed bays is a major global environmental issue. This study concentrated on a questionnaire survey and analysis of marine environmental management and monitoring departments at all levels in China, and proposed suggestions on the construction and improvement of POPs monitoring and management system. Results show that POPs are initially involved in China’s current marine environmental monitoring system, and the monitoring strength and capability still need to be continuously improved, mainly in the recognition, funding input, relevant standards, monitoring, and evaluation technical regulations of marine environmental POPs monitoring. Therefore, in order to gradually improve the monitoring and management system of China’s offshore marine environment POPs, this study suggests starting from four directions: (1) Building POPs monitoring system of a marine ecological environment, and strengthening POPs monitoring in different environmental media; (2) strengthening land-based POPs emission and the related human activities’ intensity survey, and establishing a POPs information sharing database; (3) optimizing POPs monitoring technology in the marine environment, and improving POPs supervision and management technical support system; and (4) participating in regional and international marine environment POPs monitoring and evaluation projects, and strengthening the construction of talent teams.
Wenlu Zhao; Huorong Chen; Jun Wang; Mingyu Zhang; Kai Chen; Yali Guo; Hongwei Ke; Wenyi Huang; Lihua Liu; Shengyun Yang; Minggang Cai. Current Status, Challenges, and Policy Recommendations of China’s Marine Monitoring Systems for Coastal Persistent Organic Pollution Based on Experts’ Questionnaire Analysis. International Journal of Environmental Research and Public Health 2019, 16, 3083 .
AMA StyleWenlu Zhao, Huorong Chen, Jun Wang, Mingyu Zhang, Kai Chen, Yali Guo, Hongwei Ke, Wenyi Huang, Lihua Liu, Shengyun Yang, Minggang Cai. Current Status, Challenges, and Policy Recommendations of China’s Marine Monitoring Systems for Coastal Persistent Organic Pollution Based on Experts’ Questionnaire Analysis. International Journal of Environmental Research and Public Health. 2019; 16 (17):3083.
Chicago/Turabian StyleWenlu Zhao; Huorong Chen; Jun Wang; Mingyu Zhang; Kai Chen; Yali Guo; Hongwei Ke; Wenyi Huang; Lihua Liu; Shengyun Yang; Minggang Cai. 2019. "Current Status, Challenges, and Policy Recommendations of China’s Marine Monitoring Systems for Coastal Persistent Organic Pollution Based on Experts’ Questionnaire Analysis." International Journal of Environmental Research and Public Health 16, no. 17: 3083.
Sediments at marine cold seep areas provide potential archives of past fluid flow, which allow insights into the evolution of past methane seepage activities. However, signals for anaerobic oxidation of methane (AOM) might be obscured in bulk sediments in cold-seep settings due to several factors, especially flood and turbidite deposition. Comprehensive inorganic data were gathered in this study to explore the availability of related records at cold seeps and to provide insights into the evolution of past methane seepage activities. Sediments collected from the site 973-4 in the Taixinan Basin on the northern slope of the South China Sea were characterized in terms of total carbon and sulfur, δ13C values of total organic carbon (δ13CTIC), δ34S values of chromium reducible sulfur (δ34SCRS), and foraminiferal oxygen and carbon isotopes. The results confirmed a strong correlation between formation of authigenic minerals and AOM. Moreover, the 34S enrichments and abundant chromium reducible sulfur (CRS) contents in the authigenic sulfides in the sulfate-methane transition zone (SMTZ) within 619-900 cm below seafloor (cmbsf) reflected past high methane fluxes supported by constant methane seepages. Lithological distribution and AMS (Accelerator Mass Spectra) 14C dating of planktonic foraminifera show that the turbidite (~35.14 ka) was related to a foraminifera-rich interval (Unit II: 440-619 cmbsf) and increased carbonate productivity during the last glacial maximum (LGM). Enrichment of Mo and U was observed accompanied by low contents of nutrient metals (Al, Ti, V, Ni, Fe, Mn, and Cu) in Unit II. The foraminifera-rich interval (Unit II) of cold seep sediments was probably linked to the phenomenon of inconsecutive sedimentary sequence due to the turbidites, which resulted in the lack of Fe, Mn, and Ba enrichment. There is no U enrichment but only Mo enrichment within Unit III, which might be related to H2S produced by AOM during the methane seepages. Based on the above results, it can be speculated that this area has experienced multiple-episodes of methane seep events. Further exploration of AOM should focus on the risks of rapid deposition, especially the impact of turbidity current on sediments.
DaiDai Wu; Tiantian Sun; Rui Xie; Mengdi Pan; Xuegang Chen; Ying Ye; Lihua Liu; Nengyou Wu. Characteristics of Authigenic Minerals around the Sulfate-Methane Transition Zone in the Methane-Rich Sediments of the Northern South China Sea: Inorganic Geochemical Evidence. International Journal of Environmental Research and Public Health 2019, 16, 2299 .
AMA StyleDaiDai Wu, Tiantian Sun, Rui Xie, Mengdi Pan, Xuegang Chen, Ying Ye, Lihua Liu, Nengyou Wu. Characteristics of Authigenic Minerals around the Sulfate-Methane Transition Zone in the Methane-Rich Sediments of the Northern South China Sea: Inorganic Geochemical Evidence. International Journal of Environmental Research and Public Health. 2019; 16 (13):2299.
Chicago/Turabian StyleDaiDai Wu; Tiantian Sun; Rui Xie; Mengdi Pan; Xuegang Chen; Ying Ye; Lihua Liu; Nengyou Wu. 2019. "Characteristics of Authigenic Minerals around the Sulfate-Methane Transition Zone in the Methane-Rich Sediments of the Northern South China Sea: Inorganic Geochemical Evidence." International Journal of Environmental Research and Public Health 16, no. 13: 2299.
Cold seep emissions of low temperature fluid from the marine sediment basins are mainly comprised of methane and other hydrocarbons. A series of biogeochemical processes related to methane lead to the formation of authigenic carbonate minerals. In this study, a self-built experimental device was used to study the formation process of carbonate minerals under cold seep conditions. The concentrations of pore water chemicals, HCO3- and Ca2+ at different heights of the reactor under flow conditions can be observed. According to the experimental results, the formation process of carbonate minerals under cold seep conditions was estimated, that 1 m carbonate growth needs 12,000 and 7000 years, respectively, under fast (5 mL·min-1) and slow emission (1 mL·min-1) conditions. Furthermore, TOUGHREACT was used to simulate the diagenesis process. A 1D unsteady react-transport model was developed, and the experimental data was used to constrain the simulation. The results of simulation show that the carbonates need 17,000 and 9700 years to grow 1 m under the condition of fast and slow flow scenarios, respectively. The results of this work will contribute to the study of foundation on the formation of authigenic minerals in cold seep areas, and for the physical properties of sedimentary media as well.
Tao Ye; Guangrong Jin; DaiDai Wu; Lihua Liu; Ye; Jin; Wu; Liu; and LiHua Liu. Experimental and Numerical Simulation of the Formation of Cold Seep Carbonates in Marine Sediments. International Journal of Environmental Research and Public Health 2019, 16, 1433 .
AMA StyleTao Ye, Guangrong Jin, DaiDai Wu, Lihua Liu, Ye, Jin, Wu, Liu, and LiHua Liu. Experimental and Numerical Simulation of the Formation of Cold Seep Carbonates in Marine Sediments. International Journal of Environmental Research and Public Health. 2019; 16 (8):1433.
Chicago/Turabian StyleTao Ye; Guangrong Jin; DaiDai Wu; Lihua Liu; Ye; Jin; Wu; Liu; and LiHua Liu. 2019. "Experimental and Numerical Simulation of the Formation of Cold Seep Carbonates in Marine Sediments." International Journal of Environmental Research and Public Health 16, no. 8: 1433.
Integrated investigations have revealed abundant resources of gas hydrates on the northern slope of the South China Sea (SCS). Regarding the gas hydrate research of northern SCS, the gas hydrate related environment problem such as seabed landslides were also concentrated on in those areas. Based on 2D seismic data and sub-bottom profiles of the gas hydrate areas, submarine landslides in the areas of Qiongdongnan, Xisha, Shenhu, and Dongsha have been identified, characterized, and interpreted, and the geophysical characteristics of the northern SCS region investigated comprehensively. The results show 6 major landslides in the gas hydrate zone of the northern SCS and 24 landslides in the Shenhu and Dongsha slope areas of the northern SCS. The landslide zones are located mainly at water depths of 200–3000 m, and they occur on the sides of valleys on the slope, on the flanks of volcanoes, and on the uplifted steep slopes above magmatic intrusions. All landslides extend laterally towards the NE or NEE and show a close relationship to the ancient coastline and the steep terrain of the seabed. We speculate that the distribution and development of submarine landslides in this area has a close relationship with the tectonic setting and sedimentary filling characteristics of the slopes where they are located. Seismic activity is the important factor controlling the submarine landslide in Dongsha area, but the important factor controlling the submarine landslides in Shenhu area is the decomposition of natural gas hydrates.
Xuemin Wu; Qianyong Liang; Yun Ma; Yaohong Shi; Zhen Xia; Lihua Liu; Matthias Haeckel. Submarine Landslides and their Distribution in the Gas Hydrate Area on the North Slope of the South China Sea. Energies 2018, 11, 3481 .
AMA StyleXuemin Wu, Qianyong Liang, Yun Ma, Yaohong Shi, Zhen Xia, Lihua Liu, Matthias Haeckel. Submarine Landslides and their Distribution in the Gas Hydrate Area on the North Slope of the South China Sea. Energies. 2018; 11 (12):3481.
Chicago/Turabian StyleXuemin Wu; Qianyong Liang; Yun Ma; Yaohong Shi; Zhen Xia; Lihua Liu; Matthias Haeckel. 2018. "Submarine Landslides and their Distribution in the Gas Hydrate Area on the North Slope of the South China Sea." Energies 11, no. 12: 3481.
Early diagenesis affects the distribution of solutes and minerals in unconsolidated sediments. The investigation of diagenesis is critical to understanding the geochemical transformation and benthic fluxes of elements. During the cruise mission SO-177 in 2004, gravity coring samples were recovered in the Haiyang 4 Area of the northern slope of the South China Sea (SCS). The geochemical concentrations in interstitial water were determined onboard. The 1D C.CANDI reactive transport software was used to model the early diagenesis processes at four sites: 56-GC-3, 70-GC-9, 94-GC-11, and 118-GC-13. All of the simulations reproduced concentration profiles that matched the measurements with the implemented geochemical reactions. The degradation of organic carbon and anaerobic oxidation of methane (AOM) primarily determine the distribution of solutes in the working area. The degradation is active in the top 150 cm, and AOM is vigorous at depths below 200 cm. The local advective flux, sediment rate, and kinetic reaction constants of organic matter, methane and sulfate were calibrated based on the existing concentrations of pore water solutes. Geochemical reactions in this area occur in considerably deeper layers compared to depths cited in the literature. The model results provide evidence for the existence of deep hydrocarbon reservoirs that provide methane to the upper sediments.
Lihua Liu; Roger Luff; Haibing Shao; Olaf Kolditz; Nengyou Wu. Numerical modeling of early diagenetic processes in Haiyang 4 Area in the northern slope of the South China Sea. Environmental Earth Sciences 2017, 76, 453 .
AMA StyleLihua Liu, Roger Luff, Haibing Shao, Olaf Kolditz, Nengyou Wu. Numerical modeling of early diagenetic processes in Haiyang 4 Area in the northern slope of the South China Sea. Environmental Earth Sciences. 2017; 76 (13):453.
Chicago/Turabian StyleLihua Liu; Roger Luff; Haibing Shao; Olaf Kolditz; Nengyou Wu. 2017. "Numerical modeling of early diagenetic processes in Haiyang 4 Area in the northern slope of the South China Sea." Environmental Earth Sciences 76, no. 13: 453.
Methane seepage is the signal of the deep hydrocarbon reservoir. The determination of seepage is significant to the exploration of petroleum, gas and gas hydrate. The seepage habits microbial and macrofaunal life which is fueled by the hydrocarbons, the metabolic byproducts facilitate the precipitation of authigenic minerals. The study of methane seepage is also important to understand the oceanographic condition and local ecosystem. The seepage could be active or quiescent at different times. The geophysical surveys and the geochemical determinations reveal the existence of seepage. Among these methods, only geochemical determination could expose message of the dormant seepages. The active seepage demonstrates high porewater methane concentration with rapid SO42– depleted, low H2S and dissolved inorganic carbon (DIC), higher rates of sulfate reduction (SR) and anaerobic oxidation of methane (AOM). The quiescent seepage typically develops authigenic carbonates with specific biomarkers, with extremely depleted 13C in gas, DIC and carbonates and with enriched 34S sulfate and depleted 34S pyrite. The origin of methane, minerals precipitation, the scenario of seepage and the possible method of immigration could be determined by the integration of solutes concentration, mineral composition and isotopic fractionation of carbon, sulfur. Numerical models with the integrated results provide useful insight into the nature and intensity of methane seepage occurring in the sediment and paleooceanographic conditions. Unfortunately, the intensive investigation of a specific area with dormant seep is still limit. Most seepage and modeling studies are site-specific and little attempt has been made to extrapolate the results to larger scales. Further research is thus needed to foster our understanding of the methane seepage.
Lihua Liu; Shaoying Fu; Mei Zhang; Hongxiang Guan; Nengyou Wu. Coupled carbon and sulfur isotope behaviors and other geochemical perspectives into marine methane seepage. Acta Oceanologica Sinica 2017, 36, 12 -22.
AMA StyleLihua Liu, Shaoying Fu, Mei Zhang, Hongxiang Guan, Nengyou Wu. Coupled carbon and sulfur isotope behaviors and other geochemical perspectives into marine methane seepage. Acta Oceanologica Sinica. 2017; 36 (6):12-22.
Chicago/Turabian StyleLihua Liu; Shaoying Fu; Mei Zhang; Hongxiang Guan; Nengyou Wu. 2017. "Coupled carbon and sulfur isotope behaviors and other geochemical perspectives into marine methane seepage." Acta Oceanologica Sinica 36, no. 6: 12-22.
The distribution and inventory of gas hydrates in a region is determined by the sediment characteristics, methane supply and evolution of the reservoir. In recent decades, the geo-environmental constraints and sources of methane have been intensively investigated, and numerous experimental and numerical simulation tools have been developed to evaluate the inventory of hydrates. However, information regarding the evolution of hydrate reservoirs remains limited. This study developed a simulator to theoretically model the evolution of specific reservoirs since the last glacial maximum (LGM). The LGM was a recent cold epoch that occurred approximately 18,000 years ago. Since the LGM, the earth’s climate system has experienced a continuous increase of surface temperature and rising sea level. Given a sufficient supply of methane and a transport system, hydrates may form in marine sediments if sea level rises or melt if the temperature increases. A one-dimensional simulator that represents the sediment was developed and uses the current hydrate profiles as the initial conditions and reliable paleoenvironmental data obtained in sites located in the northern shelf of the South China Sea (SCS) as boundary conditions. Two types of hydrate profiles were reversely simulated till the LGM: (1) a Gaussian profile, which was observed in the Shenhu area and (2) a trapezoidal profile, which was observed in the Dongsha area, SCS. The evolution and past quantities of local hydrate reservoirs were estimated. The model results demonstrated that shallow (500–700 m below the seafloor, or mbsf) moderate-saturation (50 % pore volume, or v:v) hydrate deposits will form if they are subjected to recent climate changes. The inventory of hydrates in the NSCS increased by only 0–7 % over the past 18,000 years under various scenarios. A sensitivity analysis was performed to identify the most pertinent parameters that control the formation and dissociation of hydrates, including the grain size, temperature gradient and deposition depth. The distribution and depth of the reservoir were determined to be the most critical factors in the evolution of the studied hydrates.
Lihua Liu; Haibing Shao; Shaoying Fu; Nengyou Wu. Theoretical simulation of the evolution of methane hydrates in the case of Northern South China Sea since the last glacial maximum. Environmental Earth Sciences 2016, 75, 1 -16.
AMA StyleLihua Liu, Haibing Shao, Shaoying Fu, Nengyou Wu. Theoretical simulation of the evolution of methane hydrates in the case of Northern South China Sea since the last glacial maximum. Environmental Earth Sciences. 2016; 75 (7):1-16.
Chicago/Turabian StyleLihua Liu; Haibing Shao; Shaoying Fu; Nengyou Wu. 2016. "Theoretical simulation of the evolution of methane hydrates in the case of Northern South China Sea since the last glacial maximum." Environmental Earth Sciences 75, no. 7: 1-16.
It occurs worldwide that the organic components of non-aqueous phase liquid (NAPL) enter the porous medium and become the source of contaminants in the subsurface. The transport of the organic components through NAPL interphase into the aqueous phase and the subsurface determines the extent of contamination, the persistence of residual NAPL phases and the techniques of remediation. During the transport process the NAPL interphase may experience “aging”, a physical and chemical change when NAPL is exposed to aqueous and or gaseous phases. This aging process alters vice versa the mass transfer behaviour of the organic contaminants in the porous medium.
Lihua Liu; Stefan Haderlein. A review on the aging phenomena of organic components and their mass transfer through the NAPL interfacial phase. Chinese Journal of Geochemistry 2013, 32, 252 -260.
AMA StyleLihua Liu, Stefan Haderlein. A review on the aging phenomena of organic components and their mass transfer through the NAPL interfacial phase. Chinese Journal of Geochemistry. 2013; 32 (3):252-260.
Chicago/Turabian StyleLihua Liu; Stefan Haderlein. 2013. "A review on the aging phenomena of organic components and their mass transfer through the NAPL interfacial phase." Chinese Journal of Geochemistry 32, no. 3: 252-260.
Subcooled liquid solubility is the water solubility for a hypothetical state of liquid. It is an important parameter for multicomponent nonaqueous phase liquids (NAPLs) containing polycyclic aromatic hydrocarbons (PAHs), which can exist as liquids even though most of the solutes are solid in their pure form at ambient temperature. So far, subcooled liquid solubilities were estimated from the solid water solubility and fugacity ratio of the solid and (subcooled) liquid phase, but rarely derived from experimental data. In our study, partitioning batch experiments were performed to determine the subcooled liquid solubility of PAHs in NAPL-water system. For selected PAH, a series of batch experiments were carried out at increased mole fractions of the target component in the NAPL and at a constant NAPL/water volume ratio. The equilibrium aqueous PAH concentrations were measured with HPLC and/or GC-MS. The subcooled liquid solubility was derived by extrapolation of the experimental equilibrium aqueous concentration to a mole fraction of unity. With the derived subcooled liquid solubility, the fugacity ratio and enthalpy of fusion of the solute were also estimated. Our results show a good agreement between the experimentally determined and published data.
Lihua Liu; Fei Wu; Stefan Haderlein; Peter Grathwohl. Determination of the subcooled liquid solubilities of PAHs in partitioning batch experiments. Geoscience Frontiers 2012, 4, 123 -126.
AMA StyleLihua Liu, Fei Wu, Stefan Haderlein, Peter Grathwohl. Determination of the subcooled liquid solubilities of PAHs in partitioning batch experiments. Geoscience Frontiers. 2012; 4 (1):123-126.
Chicago/Turabian StyleLihua Liu; Fei Wu; Stefan Haderlein; Peter Grathwohl. 2012. "Determination of the subcooled liquid solubilities of PAHs in partitioning batch experiments." Geoscience Frontiers 4, no. 1: 123-126.