High concentrated and heterogeneous distribution of gas hydrates have been identified in the gas hydrate production test region in the Shenhu area,South China Sea.The gas hydrate-bearing sediments with high saturation...High concentrated and heterogeneous distribution of gas hydrates have been identified in the gas hydrate production test region in the Shenhu area,South China Sea.The gas hydrate-bearing sediments with high saturation locate at two ridges of submarine canyon with different thickness and saturations just above the bottom simulating reflection.The crossplots of gamma ray,acoustic impedance(P-impedance)and porosity at four sites show that the sediments can be divided into the upper and lower layers at different depths,indicating different geotechnical reservoir properties.Therefore,the depositional environments and physical properties at two ridges are analyzed and compared to show the different characteristics of hydrate reservoir.High porosity,high P-wave velocity,and coarse grain size indicate better reservoir quality and higher energy depositional environment for gas hydrate at Sites W18 and W19 than those at Sites W11 and W17.Our interpretation is that the base of canyon deposits at Sites W18 and W19 characterized by upward-coarsening units may be turbidity sand layers,thus significantly improving the reservoir quality with increasing gas hydrate saturation.The shelf and slope sliding deposits compose of the fine-grained sediments at Sites W11 and W17.The gas hydrate production test sites were conducted at the ridge of W11 and W17,mainly because of the thicker and larger area of gas hydrate-bearing reservoirs than those at Sites W18 and W19.All the results provide useful insights for assessing reservoir quality in the Shenhu area.展开更多
Sludge is the by-product of wastewater treatment process. Multisource sludge can be defined as sludge from different sources. Based on the sludge properties of five typical cities in the Yangtze River basin, including...Sludge is the by-product of wastewater treatment process. Multisource sludge can be defined as sludge from different sources. Based on the sludge properties of five typical cities in the Yangtze River basin, including Jiujiang, Wuhu, Lu’an, Zhenjiang and Wuhan, this study investigated and summarized the characteristic variations and distribution differences of multiple indicators and substances from municipal sludge, dredged sludge, and river and lake sediments. The results demonstrated pH of multisource sludge was relatively stable in the neutral range. Organic matter and water content among municipal sludge were high and varied considerably between different wastewater treatment plants. Dredged sludge had an obviously higher sand content and wider particle distribution, which could be considered for graded utilization depending on its size. The nutrients composition of river and lake sediments was usually stable and special, with lower nitrogen and phosphorus content but higher potassium levels. The sources of heavy metals and persistent organic pollutants in multisource sludge were correlated, generally much higher among municipal sludge than dredged sludge and river and lake sediments, which were the most important limitation for final land utilization. Despite various properties of multisource sludge, the final fate and destination have some overall similarities, which need to be supplemented and improved by standards and laws. The study provided a preliminary analysis of suitable technical routes for municipal sludge, dredged sludge, river and lake sediments based on their different characteristics respectively, which was of great significance for multisource sludge co-treatment and disposal in the future of China.展开更多
基金Supported by the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(No.GML2019ZD0104)the National Natural Science Foundation of China(Nos.U19B2005,42076072)+1 种基金the Pilot National Laboratory for Marine Science and Technology(Qingdao)Initial Foundation(No.JCZX202019)the Research Start-up Funds of Zhufeng Scholars Program。
文摘High concentrated and heterogeneous distribution of gas hydrates have been identified in the gas hydrate production test region in the Shenhu area,South China Sea.The gas hydrate-bearing sediments with high saturation locate at two ridges of submarine canyon with different thickness and saturations just above the bottom simulating reflection.The crossplots of gamma ray,acoustic impedance(P-impedance)and porosity at four sites show that the sediments can be divided into the upper and lower layers at different depths,indicating different geotechnical reservoir properties.Therefore,the depositional environments and physical properties at two ridges are analyzed and compared to show the different characteristics of hydrate reservoir.High porosity,high P-wave velocity,and coarse grain size indicate better reservoir quality and higher energy depositional environment for gas hydrate at Sites W18 and W19 than those at Sites W11 and W17.Our interpretation is that the base of canyon deposits at Sites W18 and W19 characterized by upward-coarsening units may be turbidity sand layers,thus significantly improving the reservoir quality with increasing gas hydrate saturation.The shelf and slope sliding deposits compose of the fine-grained sediments at Sites W11 and W17.The gas hydrate production test sites were conducted at the ridge of W11 and W17,mainly because of the thicker and larger area of gas hydrate-bearing reservoirs than those at Sites W18 and W19.All the results provide useful insights for assessing reservoir quality in the Shenhu area.
基金supported by the Scientific Research Project of China Three Gorges Corporation, China (No. 202003081)the National Key Research and Development Program of China (No. 2020YFC1908702)the National Natural Science Foundation of China (NSFC) (No. 52131002)。
文摘Sludge is the by-product of wastewater treatment process. Multisource sludge can be defined as sludge from different sources. Based on the sludge properties of five typical cities in the Yangtze River basin, including Jiujiang, Wuhu, Lu’an, Zhenjiang and Wuhan, this study investigated and summarized the characteristic variations and distribution differences of multiple indicators and substances from municipal sludge, dredged sludge, and river and lake sediments. The results demonstrated pH of multisource sludge was relatively stable in the neutral range. Organic matter and water content among municipal sludge were high and varied considerably between different wastewater treatment plants. Dredged sludge had an obviously higher sand content and wider particle distribution, which could be considered for graded utilization depending on its size. The nutrients composition of river and lake sediments was usually stable and special, with lower nitrogen and phosphorus content but higher potassium levels. The sources of heavy metals and persistent organic pollutants in multisource sludge were correlated, generally much higher among municipal sludge than dredged sludge and river and lake sediments, which were the most important limitation for final land utilization. Despite various properties of multisource sludge, the final fate and destination have some overall similarities, which need to be supplemented and improved by standards and laws. The study provided a preliminary analysis of suitable technical routes for municipal sludge, dredged sludge, river and lake sediments based on their different characteristics respectively, which was of great significance for multisource sludge co-treatment and disposal in the future of China.
