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松花江底积物中多环芳烃生态风险评价 被引量:11
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作者 聂海峰 李括 +2 位作者 彭敏 刘飞 杨柯 《中国地质》 CAS CSCD 北大核心 2011年第4期1102-1110,共9页
对松花江底积物中16种多环芳烃类化合物(PAHs)进行调查结果显示,松花江底积物中属于美国EPA优先控制的16种PAHs全被检出。16种PAHs总含量范围226.86~10079.68 ng.g-1,平均含量为2230.04 ng.g-1。其中,4环和5~6环PAHs的相对丰度为61.6... 对松花江底积物中16种多环芳烃类化合物(PAHs)进行调查结果显示,松花江底积物中属于美国EPA优先控制的16种PAHs全被检出。16种PAHs总含量范围226.86~10079.68 ng.g-1,平均含量为2230.04 ng.g-1。其中,4环和5~6环PAHs的相对丰度为61.6%,2~3环PAHs的相对丰度为38.4%,研究表明松花江底积物中PAHs主要来源于生物化石燃料燃烧,仅支流嫩江齐齐哈尔下游段、干流肇源县西段主要体现为石油类输入。就松花江PAHs生态风险而言:在第二松花江吉林市上游、吉林市下游段,PAHs遍及低环、中环、高环都超过了生态效应警戒值低值(ERL);嫩江支流泰来东南段PAHs组分萘(Nap)、苊(Ace)、芴(Fl),松花江干流巴彦段二苯并[a,h]蒽(DBA)也超过了生态效应警戒值低值(ERL)。这说明这些超ERL值的河段底积物中PAHs对裸露生物体的毒副作用风险率大于10%,具有一定的潜在生态风险。 展开更多
关键词 松花江 多环芳烃 底积物 来源 风险评价
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丹江口水库土壤-底积物镉生态地球化学风险评价 被引量:3
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作者 徐宏林 李梦茹 +4 位作者 姜华 杨清富 赵计伟 胡绍祥 周小娟 《中国地质》 CAS CSCD 北大核心 2021年第4期1166-1176,共11页
湖北省十堰—丹江口地区多目标地球化学调查由中国地质科学院地球物理地球化学勘查研究所2013—2015年组织实施,旨在查明测区元素地球化学分布和分配特征,开展国土资源环境评价与基础地质研究,为国家及地方经济社会科学可持续发展提供... 湖北省十堰—丹江口地区多目标地球化学调查由中国地质科学院地球物理地球化学勘查研究所2013—2015年组织实施,旨在查明测区元素地球化学分布和分配特征,开展国土资源环境评价与基础地质研究,为国家及地方经济社会科学可持续发展提供基础资料。调查发现了丹江口水库底积物及沿汉江土壤镉富集现象。为保护丹江口水源地及南水北调水质安全,系统研究了丹江口库区不同生态区土壤、底积物中镉含量特点,计算了镉含量背景值和富集因子,为水库镉污染防治和生态修复提供了依据。镉生态地球化学风险评价显示,调查的样点中,100%消落区土壤、100%汉江底积物,99.45%深层土壤和92.41%的表层土壤属于农用地镉污染风险低土壤。水库底积物样点中低、中、高潜在生态风险比例分别占15.52%、20.69%、63.79%。分析了土壤和底积物中镉含量与pH值、Corg、常量元素含量的关系;建议通过切断上游污染源,防止水土流失,防治土壤酸化,开展生态修复等措施来防治库区底积物的镉污染、降低其生态风险。 展开更多
关键词 土壤 底积物 生态地球化学风险 地质调查工程 南水北调水源地 丹江口水库 湖北
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左江流域龙州段底积物重金属含量来源分析与生态风险评价
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作者 吴含志 《南方国土资源》 2021年第8期40-44,共5页
文章对左江流域龙州段28件底积物中8种重金属含量的空间分布特征、来源、影响因素进行了分析及生态风险评估。研究发现其平均含量略高于西南五省(区、市)(四川省、贵州省、云南省、西藏自治区、重庆市)水系背景值,但低于全球淡水沉积物... 文章对左江流域龙州段28件底积物中8种重金属含量的空间分布特征、来源、影响因素进行了分析及生态风险评估。研究发现其平均含量略高于西南五省(区、市)(四川省、贵州省、云南省、西藏自治区、重庆市)水系背景值,但低于全球淡水沉积物环境质量标准和龙州土壤背景值。其中,元素Cr、Zn含量相对较高,而Cd元素和Hg元素含量较低。Hakanson生态风险指数法评价结果表明,龙州流域28件底积物样品重金属含量属于低生态风险等级。皮尔斯相关分析和主成分分析表明,龙州流域底积物中重金属含量主要来源于碳酸盐岩的风化贡献,且受有机碳含量的影响。 展开更多
关键词 左江龙州段 底积物重金属 来源分析 生态风险评价
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W洞洞底堆积物工程地质特征及建筑性能评价
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作者 刘立人 《沈阳黄金学院学报》 1992年第1期20-27,共8页
关键词 工程地质特征 建筑性能
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武汉城市湖泊环境地球化学研究——以东湖为例 被引量:10
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作者 苏秋克 蒋敬业 +1 位作者 姜益善 马振东 《安全与环境工程》 CAS 2003年第3期5-8,共4页
选择武汉市具有代表性的城市湖泊——东湖,进行湖泊底积物及湖水的环境地球化学研究,主要研究了湖水电导率(Ec)的变化趋势和湖泊底积物中重金属Cu、Pb、Zn、Cd、Hg等元素含量的变化规律,最后得出:武汉东湖已经开始受到重金属污染,重金... 选择武汉市具有代表性的城市湖泊——东湖,进行湖泊底积物及湖水的环境地球化学研究,主要研究了湖水电导率(Ec)的变化趋势和湖泊底积物中重金属Cu、Pb、Zn、Cd、Hg等元素含量的变化规律,最后得出:武汉东湖已经开始受到重金属污染,重金属污染是人类活动直接影响的后果。 展开更多
关键词 武汉市 城市湖泊 环境地球化学 重金属污染 东湖 底积物
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Influence of Microstructure Change of Seafloor Sediments on the Sound Velocity in them in the Course of Stress-strain
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作者 李赶先 卢博 黄韶健 《Marine Science Bulletin》 CAS 2009年第1期62-69,共8页
Test tools and methods for synchronizing acoustic measurements in the course of stress-strain for seafloor sediment are elaborated and the test data of 45 sediment samples from the seafloor in the South China Sea are ... Test tools and methods for synchronizing acoustic measurements in the course of stress-strain for seafloor sediment are elaborated and the test data of 45 sediment samples from the seafloor in the South China Sea are analysed. The result shows that the coarser the sediment grains are, the smaller the porosity is and the larger the unconfined compression strength is, the higher the sound velocity is. In the course of stress-strain, the sediment sound velocity varies obviously with the stress. Acoustic characteristics of sediment in different strain phases and the influence of sediment microstructure change on its sound velocity are discussed. This study will be of important significance for surveying wells of petroleum geology and evaluating the base stabilization of seafloor engineering. 展开更多
关键词 seafloor sediment STRESS-STRAIN microstructure features sound velocity compression strength
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Occurrence and Diversity of Marine Yeasts in Antarctica Environments 被引量:12
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作者 ZHANG Xue HUA Mingxia +1 位作者 SONG Chunli CHI Zhenming 《Journal of Ocean University of China》 SCIE CAS 2012年第1期70-74,共5页
A total of 28 yeast strains were obtained from the sea sediment of Antarctica.According to the results of routine identi-fication and molecular characterization,the strains belonged to species of Yarrowia lipolytica,D... A total of 28 yeast strains were obtained from the sea sediment of Antarctica.According to the results of routine identi-fication and molecular characterization,the strains belonged to species of Yarrowia lipolytica,Debaryomyces hansenii,Rhodotorula slooffiae,Rhodotorula mucilaginosa,Sporidiobolus salmonicolor,Aureobasidium pullulans,Mrakia frigida and Guehomyces pullu-lans,respectively.The Antarctica yeasts have wide potential applications in biotechnology,for some of them can produce b-galactosidase and killer toxins. 展开更多
关键词 Antarctica Psychrotolerant yeasts identification b-galactosidase killer toxin
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Dormant stages of crustaceans as a mechanism of propagation in the extreme and unpredictable environment in the Crimean hypersaline lakes 被引量:1
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作者 Nickolai V.SHADRIN Elena V.ANUFRIIEVA +1 位作者 Francisco AMAT Oleg Yu.EREMIN 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第6期1362-1367,共6页
A pool of dormant stages of planktonic organisms in saline lakes is a substantial component in the plankton communities;we need to take it into account to understand plankton dynamics.Hypersaline water bodies in Crime... A pool of dormant stages of planktonic organisms in saline lakes is a substantial component in the plankton communities;we need to take it into account to understand plankton dynamics.Hypersaline water bodies in Crimea,the largest peninsula in the Black Sea,constitute a very characteristic and peculiar habitat type in the region.We examined the presence of crustacean resting stages in sediments of dried up sites of the Crimean hypersaline lakes.Sediment samples were taken in 9 different lakes.Experiments performed on the hatching of these resting stages showed the presence of Moina salina(Cladocera),parthenogenetic Artemia and Artemia urmiana(Anostraca),Eucypris mareotica( inflata)(Ostracoda),and Cletocamptus retrogressus(Harpacticoida).Comparing the experimental results obtained with clean dried brine shrimp cysts and those kept in sediment samples,it was noted that clean cysts hatched much faster than those from sediments did.Some components in bottom sediments slow down and desynchronize hatching from resting eggs in different groups of crustaceans.The sediments of different lakes inhibited the nauplii output from Artemia and ostracod resting eggs to different degrees.More data are needed before we can discuss the reasons of this inhibition.The nonsynchronous output of active stages from the bottom resting ones may be an adaptation that allows crustacean species to exist in extreme and unpredictably changing environments,avoiding the risk that all may emerge at once under unsuitable conditions. 展开更多
关键词 resting stages hypersaline waters CRUSTACEA CRIMEA SEDIMENT
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Study on the Thermal Insulation Performance of a New Seabed Sediment Fidelity Sampler Based on ANSYS 被引量:1
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作者 LIU Guoying LIU Guijie YUAN Weijie 《Journal of Ocean University of China》 SCIE CAS 2009年第3期277-282,共6页
A new seabed sediment fidelity sampler was developed and its thermal insulation performance was studied and analyzed. The temperature distribution simulation indicated that the sample quality could be insured by using... A new seabed sediment fidelity sampler was developed and its thermal insulation performance was studied and analyzed. The temperature distribution simulation indicated that the sample quality could be insured by using this new sampler. Based on ANSYS10, the temperature finite element model of the sample cylinder was established. According to the law of conservation of energy, the unsteady heat transmit equation of the sampler under solid-liquid coupling condition was derived, then the mathematical model calculation was carried out by using a mixed finite-element finite-difference method, and two thermal insulation methods were used. The simulation was carried out by using the thickness of the thermal insulation layer and heat conductivity as the variable parameters and the temperature distribution of the sampler and related influencing factors were obtained. Optimization analysis was conducted using the simulation data and related parameters and the magnitude ranges of the parameters were obtained that could meet the design temperature requirements. The experimental data and simulation results indicated that the results were in good agreement with the realities, and this sampler might be of value for seabed sediment sampler design and manufacture. 展开更多
关键词 sea bed sediment SAMPLER ANSYS thermal insulation method temperature field
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A smart calibration model on track's pressure-sinkage characteristic of a tracked vehicle moving on soft seabed sediments 被引量:1
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作者 曾谊晖 周育才 +1 位作者 刘道才 左青松 《Journal of Central South University》 SCIE EI CAS 2013年第4期911-917,共7页
The bentonite-water mixture was selected as the substitute of seabed sediments according to the in-situ measurement data of sediments 15-20 cm deep in China's ocean poly-metallic mining contract area and the soft ... The bentonite-water mixture was selected as the substitute of seabed sediments according to the in-situ measurement data of sediments 15-20 cm deep in China's ocean poly-metallic mining contract area and the soft seabed sediments could be simulated with certain proportion of the bentonite and water; besides, based on the theory on the interaction between the vehicle and ground and referenced to Bekker's apparatus and related experimental methods, a scenario on the experimental system of the pressure-sinkage characteristics of interaction between the track of tracked vehicle and soft seabed sediments was designed. The pressure-sinkage experiments were performed with different dimensions of penetration plates. The "pressure-sinkage" model based on Bekker's formula and correlation parameters were obtained to describe the corresponding characteristics of the seabed sediments and a smart calibration model on the pressure-sinkage characteristic of the track was established based on the function chain neural network, which could provide boundary loading conditions for simulation analysis of the tracked vehicle moving on the seabed. 展开更多
关键词 tracked vehicle TRACK seabed sediments pressure-sinkage characteristic smart calibration
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Tests of new in-situ seabed acoustic measurement system in Qingdao 被引量:1
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作者 侯正瑜 郭常升 +2 位作者 王景强 李会银 李铁刚 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2014年第5期1172-1178,共7页
A new in-situ seabed acoustic measurement system is developed for direct in-situ measurement of sediment geoacoustic properties (compressional wave velocity and attenuation). The new in-situ system consists of two p... A new in-situ seabed acoustic measurement system is developed for direct in-situ measurement of sediment geoacoustic properties (compressional wave velocity and attenuation). The new in-situ system consists of two parts: the deck control unit and the underwater measurement unit. The underwater measurement unit emits sonic waves that propagate through the seafloor sediment, receives the returning signals, and transmits them to the deck control unit for waveform display and analysis. The entire operation is controlled and monitored in real time by the deck control unit on the research vessel and can provide recording of full waveforms to determine the sound velocity and attenuation. This paper outlines the design of the system, the measurement process, and demonstrates its application in tests carded out on seabed sediment off the Qingdao coast, China. The test results show that the system performed well and rapidly provided accurate in-situ acoustic velocity and attenuation estimates of the seafloor sediment. 展开更多
关键词 seafloor sediment in-situ measurement sound velocity and attenuation.
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Accuracy of the staggered-grid finite-difference method of the acoustic wave equation for marine seismic reflection modeling 被引量:1
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作者 钱进 吴时国 崔若飞 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2013年第1期169-177,共9页
Seismic wave modeling is a cornerstone of geophysical data acquisition, processing, and interpretation, for which finite-difference methods are often applied. In this paper, we extend the velocity- pressure formulatio... Seismic wave modeling is a cornerstone of geophysical data acquisition, processing, and interpretation, for which finite-difference methods are often applied. In this paper, we extend the velocity- pressure formulation of the acoustic wave equation to marine seismic modeling using the staggered-grid finite-difference method. The scheme is developed using a fourth-order spatial and a second-order temporal operator. Then, we define a stability coefficient (SC) and calculate its maximum value under the stability condition. Based on the dispersion relationship, we conduct a detailed dispersion analysis for submarine sediments in terms of the phase and group velocity over a range of angles, stability coefficients, and orders. We also compare the numerical solution with the exact solution for a P-wave line source in a homogeneous submarine model. Additionally, the numerical results determined by a Marmousi2 model with a rugged seafloor indicate that this method is sufficient for modeling complex submarine structures. 展开更多
关键词 marine seismic reflection modeling stability condition dispersion relation staggered grid finite-difference
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Temporal Changes in Transboundary Air Pollutants in Bottom Sediments of Lakes in East Asia 被引量:1
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作者 Shlntaro Mura Ryosuke Sato +5 位作者 Masaki Hashimoto Akiko Murakami-Kitase Hideo Yamazaki Shusaku Yoshikawa Ju-Yong Kim Kazuo Kamura 《Journal of Environmental Science and Engineering(B)》 2013年第11期629-639,共11页
To clarify temporal changes in the transboundary pollution, we analyzed SCPs (spheroidal carbonaceous particles) in bottom sediments of lakes in China, South Korea and Japan. SCPs provide an unambiguous record of an... To clarify temporal changes in the transboundary pollution, we analyzed SCPs (spheroidal carbonaceous particles) in bottom sediments of lakes in China, South Korea and Japan. SCPs provide an unambiguous record of anthropogenic atmospheric pollution in bottom sediments. Recently deposited SCPs in air and unmelted snow on Mt. Fuji were also characterized. The concentrarion and characteristics of SCPs reflected the environmental and industrial history of the area. Evidence of transboundary air pollution was observed after the 1980s in Yashagaike and Kotaniike ponds in Japan, which are located on the coast of the Sea of Japan. The concentration suggests that the pollutants originated from continental Asia, particularly after the 1980s. The chemical composition of the SCPs allowed the source of emissions to be identified. Chinese SCPs were found at Yashagaike and Kotaniike ponds in Japan, and at Songiiho and Urimji lakes in Korea. The size distributions showed that small SCPs are transported over long distances. On the summit of Mr. Fuji, SCPs transported by the prevailing westerlies from China were found in addition to SCPs emitted in Japan. 展开更多
关键词 Bottom sediments transboundary air pollution SCPs.
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Sedimentary facies of the subaqueous Changjiang River delta since the late Pleistocene 被引量:3
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作者 徐涛玉 石学法 +5 位作者 王国庆 乔淑卿 杨刚 刘升发 王旭晨 赵泉鸿 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2013年第5期1107-1119,共13页
The sedimentary facies of the subaqueous Changjiang (Yangtze) River delta since the late Pleistocene was studied based on lithology and foraminifera analysis for two boreholes, CJK07 and CJK11, along with 14C dating... The sedimentary facies of the subaqueous Changjiang (Yangtze) River delta since the late Pleistocene was studied based on lithology and foraminifera analysis for two boreholes, CJK07 and CJK11, along with 14C dating. Four sedimentary facies were identified, namely fluvial, tidal flat, offshore, and prodelta facies. The fluvial sedimentary facies is comprised of fluvial channel lag deposits, fluvial point bar deposits, and floodplain deposits, showing a fining-upward sequence in general with no benthic foraminifera. A layer of stiff clay overlies the fluvial deposits in core CJK07, indicating a long-term exposure environment during the Last Glacial Maximum (LGM). During the postglacial sea-level rise around 13-7.5 cal ka BP, the tidal flat facies was deposited in core CJK11, characterized by abundant silt-clay couplets. Euryhaline species dominate the subtidal fiat foraminiferal assemblages, while almost no foraminifera was found in the intertidal fiat. The offshore environment was the major sedimentary environment when the sea level reached its highest level around 7.5 cal ka BP, with a maximum accumulation rate of 10 mm/a found in core CJK11. Prodelta sediments have been deposited in core CJK11 since -3 cal ka BP, after the formation of the Changjiang River delta. The difference in sedimentary facies between core CJK07 and CJK11 is due to their location: core CJK07 was in an interfluve while core CJK11 was in an incised valley during the LGM. Furthermore, AMS 14C dating of core CJK07 shows poor chronological order, indicating that the sediments were reworked by strong tidal currents and that sediment deposited since -7.7 cal ka BP in core CJK07 was eroded away by modem hydrodynamic forces caused by the southward shift of the Changjiang River delta depocenter. 展开更多
关键词 the subaqueous Changjiang (Yangtze) River delta sedimentary facies Last Glacial Maximum
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Relationship between in situ sound velocity and granular characteristics of seafloor sediments in the Qingdao offshore region
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作者 张严心 郭常升 +2 位作者 王景强 侯正瑜 陈文景 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2017年第3期704-711,共8页
The sound velocity of seafloor sediments from shallow seas can provide important information for harbor design, and ocean and seacoast engineering projects. In this study, in situ measurements were used to obtain accu... The sound velocity of seafloor sediments from shallow seas can provide important information for harbor design, and ocean and seacoast engineering projects. In this study, in situ measurements were used to obtain accurate sediment sound velocities at 45 stations offshore of Qingdao. The relationships between the sound velocity and granular properties of the seafloor sediments were analyzed. Sound velocity showed an increase with the sand content, sand-clay ratio, and sorting coefficient; and a nonlinear decreasing trend with increasing mean grain size and clay content. We plotted a sound velocity distribution map, which shows that the sound velocity was closely related to the geological environment. Previous empirical equations suggested by Hamilton, Anderson, and Liu were used to calculate the velocity with grain size. A comparison between the measured and calculated velocities indicates that the empirical equations have territorial limitations, and extensive data are essential to establish global empirical equations. Future work includes the calibration of the laboratory acoustic measurements with an in situ technique. 展开更多
关键词 sound velocity granular properties empirical equation
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Geochemical Studies and Elemental Contaminants in the Bay of the City of Asuncion
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作者 Juan F. Facetti-Masulli Franklin Flores Peter Kump 《Journal of Chemistry and Chemical Engineering》 2013年第11期1060-1067,共8页
Minor and trace elements composition of bottom sediments from the bay of Asunci6n on the Paraguay River have been investigated by XRF (X-ray fluorescence) techniques to determine their correlation as well as provena... Minor and trace elements composition of bottom sediments from the bay of Asunci6n on the Paraguay River have been investigated by XRF (X-ray fluorescence) techniques to determine their correlation as well as provenance. The analysis of complex spectra was performed by the AXIL software and the quantitative analysis by the QAES (quantitative analysis of environmental samples ) software. Analyzed trace elements were the refractory elements Rb, Sr, Y, Zr, Nb, Ba, La, Ce, Pr, Nd, Zr, Th and others with high field stabilization energy as Cr, Ni, Cu, together with Zn, As, Cd, Pb. Minor elements were Ti, Mn, Fe which are often to the above refractories related. According to their normalized spidergrams, two sets of sediments can be differentiated. Those that show LREE (light rare earth elements) enrichment, negative Nb and Ti anomalies and no spike at Zr and those that have spidergrams very alike, with strong negative anomalies at Nb, Nd and Ti whereas a of Fe versus the refractory elements except Fe-Zr in which correlation seem to be low. positive spike at Zr. In both set, there are strong correlations is negative. Potential hazards of toxic elements in sediments 展开更多
关键词 Bottom sediments Asuncion Bay XRF LREE Paraguay River.
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Monitoring the Morphology of the Bottom of Streams and Reservoirs Using Electrical Impedance Spectrometry Method
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作者 Jana Parilkova 《Journal of Civil Engineering and Architecture》 2010年第6期50-59,共10页
A part of the Earth's surface has been formed by the action of running water during geomorphological development. The flow of water is one of the ways of how particles can be eroded, transported and accumulated. If e... A part of the Earth's surface has been formed by the action of running water during geomorphological development. The flow of water is one of the ways of how particles can be eroded, transported and accumulated. If endogenous processes do not work, the surface of the continents would lower to the level close to the ocean surface and the relief would have almost no ruggedness. Recently, there have been talks about the relative classification of deviation of the present state from the "original" or "natural" one caused by anthropogeneous effects. The activity of man can manifest itself by pollution, the excessive use of water, a change in the flow regime, and the like. Research into the morphology of the river bottom and the bottom of settling tanks or dam reservoirs is systematically carried out in selected streams and reservoirs by the long-term sampling of bottom sediments. The knowledge of the sediment layer is also important. The EIS method, which was used for measuring, is new for the aforementioned applications. Possibilities of EIS method with new apparatus using for this application were tested in laboratory and in situ. On the basis of interpretation of the electrical conductivity data, a grid of depth data was acquired. These data are characterized by anomalously high and low "spots" and show morphological changes in the studied area. 展开更多
关键词 Electrical impedance spectrometry (EIS) physical model in-situ monitoring SLUDGE MORPHOLOGY stream bed settling tank.
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Radionuclides and mercury in the salt lakes of the Crimea
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作者 Natalya MIRZOYEVA Larisa GULINA +5 位作者 Sergey GULIN Olga PLOTITSINA Alexandra STETSUK Svetlana ARKHIPOVA Nina KORKISHKO Oleg EREMIN 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第6期1413-1425,共13页
^99Sr concentrations, resulting from the Chernobyl NPP accident, were determined in the salt lakes of the Crimea (Lakes Kiyatskoe, Kirleutskoe, Kizil-Yar, Bakalskoe and Donuzlav), together with the redistribution be... ^99Sr concentrations, resulting from the Chernobyl NPP accident, were determined in the salt lakes of the Crimea (Lakes Kiyatskoe, Kirleutskoe, Kizil-Yar, Bakalskoe and Donuzlav), together with the redistribution between the components of the ecosystems. The content of mercury in the waters of the studied reservoirs was also established. Vertical distributions of natural radionuclide activities (^238U, ^232Th, ^226Ra, ^210pb, ^40K) and anthropogenic ^137Cs concentrations (as radiotracers) were determined in the bottom sediments of the Koyashskoe salt lake (located in the south-eastern Crimea) to evaluate the long- term dynamics and biogeochemical processes. Radiochemical and chemical analysis was undertaken and radiotracer and statistical methods were applied to the analytical data. The highest concentrations of ^99Sr in the water of Lake Kiyatskoe (350.5 and 98.0 Bq/m^3) and Lake Kirleutskoe (121.3 Bq/m^3) were due to the discharge of the Dnieper water from the North-Crimean Canal. The high content of mercury in Lake Kiyatskoe (363.2 ng/L) and in seawater near Lake Kizil-Yar (364 ng/L) exceeded the maximum permissible concentration (3.5 times the maximum). Natural radionuclides provide the main contribution to the total radioactivity (artificial and natural combined) in the bottom sediments of Lake Koyashskoe. The significant concentration of ^210pb in the upper layer of bottom sediments of the lake indicates an active inflow of its parent radionuclide-gaseous ^222Rn from the lower layers of the bottom sediment. The average sedimentation rates in Lake Koyashskoe, determined using ^210pb and ^137Cs data, were 0.117 and 0.109 cm per year, respectively. 展开更多
关键词 CRIMEA salt lakes Black Sea Chernobyl NPP accident radionuclides MERCURY ecological impact
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Water Quality and Some Heavy Metals in Water and Sediments of Euphrates River, Iraq 被引量:1
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作者 Jasim Mohammed Salman Hussain Allawi Hussain 《Journal of Environmental Science and Engineering(A)》 2012年第9期1088-1095,共8页
Water samples, sediments from three stations in Euphrates River, lraq were analyzed quantitatively for some physical and chemical characters and six heavy metals (Co, Cu, Fe, Mn, Ni and Pb) using flam atomic absorpt... Water samples, sediments from three stations in Euphrates River, lraq were analyzed quantitatively for some physical and chemical characters and six heavy metals (Co, Cu, Fe, Mn, Ni and Pb) using flam atomic absorption spectrophotpmeter in period Sept. 2009-Oct. 2010. The physical and chemical characters included temperature, pH, water flow, salinity, dissolved oxygen, BOD5, alkalinity total hardness, calcium and nutrients (nitrite, nitrate reactive phosphate and silicate). The results showed variation in water flow 0.05-0.40 m/sec., according to the values of salinity 0.40%-0.60% values of the BOD5 were ranged between 0.2-4.3 mg/L. The mean concentration of the heavy metals (Pb, Ni, Mn, Co, Cu and Fe) of the dissolved phase in water were 0.13 μg/L, 0.021 μg/L, 0.31 μg/L, 4.29 μg/L, 7.78 μg/L, 6.46 μg/L and 79.04 μg/L, respectively, while their concentration in the particulate phase were 0.59 μg/g, 0.06 μg/g, 0.42 μg/g, 50.06 μg/g, 6.61 μg/g, 7.17 vg/g and 149.42 μg/g dry weight, respectively. Also the mean concentrations of heavy metals in sediment (exchangeable phase) were 0.51 vg/g,0.18 vg/g, 0.08 μg/g, 61.39 μg/g, 5.40 μg/g, 14.06 vg/g and 130.05 μg/g dry weight respectively, and 0.40 μg/g, 0.17 μg/g, 0.10 μg/g, 63.01 μg/g, 4.64 μg/g, 18.44 μg/g and 126.26 μg/g D.W. respectively in residual phase of sediment. 展开更多
关键词 Heavy metals water quality environmental pollution sediment Euphrates River.
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The Origin of Tar AI-Say'ed and Tar AI-Najaf, Karbala-Najaf Vicinity, Central Iraq
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作者 Varoujan K. Sissakian Mawahib F. Abdul Jab'bar +1 位作者 Nadhir A. Al-Ansari Sven Knutsson 《Journal of Civil Engineering and Architecture》 2015年第4期446-459,共14页
In central part of Iraq within the vicinity of Karbala-Najaf, two cliffs called "Tar Al-Say'ed" and "Tar Al-Najaf" form conspicuous geomorphological forms between the Mesopotamia Plain and the Western and Souther... In central part of Iraq within the vicinity of Karbala-Najaf, two cliffs called "Tar Al-Say'ed" and "Tar Al-Najaf" form conspicuous geomorphological forms between the Mesopotamia Plain and the Western and Southern Deserts. The top surface between the two cliffs (tars) is covered by alluvial fan sediments, laid down by A1-Khir Valley when merging in a large depression due to the drop in the gradient of the valley. Consequently, the depression was divided into two parts, to the left is called Al-Razzazah Depression, whereas to the right is called Bahir Al-Najaf. This affected the course of the River Euphrates. The deposition stopped due to an uplift movement which caused the elevation of the two cliffs which are covered by alluvial fan sediments. The two cliffs had and are still suffering from retreating, due to lateral erosion by wave actions in Al-Razzazah Depression. Springs located along a straight line, sag pond, deflected drainage, shutter ridges and pressure ridges can be noticed in the area. The age of both cliffs is estimated to be upper Late Pleistocene--early Holocene. 展开更多
关键词 NEOTECTONIC erosional cliff alluvial fan PLEISTOCENE Iraq.
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