多层渗滤介质处理微污染水体的中试研究   总被引：3，自引：0，他引：3  

侯立柱  周训  许靖华  叶文华  王文玉  杨生炯 《现代地质》2009,23(1):125-129

对传统的渗滤系统进行改进,采用多层渗滤介质系统,以期增大人工土层对颗粒有机物的接触氧化表面积,同时设置曝气装置保证好氧过程的氧气供应,可以大大提高污水地下处理系统的水力负荷。以北京典型的细砂、中砂、粗砂和砾石为填充材料,处理北京市海淀区上庄水库的污染水体,远优于类似的系统。现场试验结果表明,改进后的系统能创造良好的好氧/厌氧环境,对污染物去除效果良好,COD_Cr、TN、NH⁺₄-N和TP去除率分别达到了48.57%~94.87%、18.49%~70.21%、20.51%~87.50%和5692%~80.65%,出水达到了地表水Ⅲ-Ⅳ类水质标准。多层渗滤介质系统通过微生物的硝化、反硝化作用实现生物脱氮是去除氮的主要途径;土壤的吸附与沉淀作用是去除磷的主要途径。   相似文献   

冰后期最大海侵以来长江口潮波特性的变化   总被引：1，自引：0，他引：1  

朱玉荣 《海洋科学》2000,24(5):34-36

冰后期最大海侵时,现今长江三角洲地区为一巨大河口湾,研究古长江河口湾及其周围海域的潮波特性,并与现今长江口的进行对比,有助于深入了解长江三角洲形成发育的动力过程。根据冰后期最大海侵时古长江河口湾及其周围海域３５个计算站一个半日潮周期的潮位、潮流过程曲线得知,冰后期最大海侵时古长江河口 及其周围海域的潮波为驻波以及驻波－前进波混合型。此后,丰古长江河口被充填、长江口东进南移,长江口的潮波也逐渐转 变  相似文献   

Evolving patterns of the fluids within the TAG hydrothermal field     

HuaiMing Li  ShiKui Zhai  ZengHui Yu  ChunHui Tao  FengYou Chu 《中国科学D辑(英文版)》2009,52(1):29-37

The mixing of seawater/hydrothermal fluid within the large seafloor hydrothermal sulfide deposits plays a key role in the formation processes of the sulfide deposits. Some issues attract considerable attentions in the study of seafloor hydrothermal system in recent years, such as the relationships among different types of vent fluids, the characteristics of chemical compositions and mineral assemblages of the hydrothermal deposits and their governing factors. Combined with the measured data of hydrothermal fluid in the TAG field, the thermodynamic model of mixing processes of the heated seawater at different temperatures and the hydrothermal fluid is calculated to understand the precipitation mechanism of anhydrite and the genetic relationships between the black and white smoker fluids within the TAG mound. The results indicate that the heating of seawater and the mixing of hydrothermal fluid/seawater are largely responsible for anhydrite precipitation and the temperature of the heated seawater is not higher than 150°C and the temperature of the end-member hydrothermal fluid is not lower than 400°C. Based on the simulated results, the evolving patterns of fluids within the TAG deposit are discussed. The mixed fluid of the end-member hydrothermal fluid and the seawater heated by wall rock undergoes conductive cooling during upflowing within the deposit and forms “White Smoker” eventually. In addition, the end-member hydrothermal fluid without mixed with seawater, but undergoing conductive cooling, vents out of the deposit and forms “Black Smoker”. Supported by China Ocean Mineral Resources Research and Development Association Program (Grant No. DY115-02-1-01) and National Basic Research Program of China (Grant No. G2000078503)  相似文献   

电磁方法在海底多金属硫化物探测中的应用     

熊威  陶春辉  邓显明 《海洋学研究》2013,31(2):59-64

海底硫化物矿体的三维展布是当前大洋调查急需解决的关键问题,在陆地上电磁方法一直是解决矿产资源三维问题的重要手段之一。2011年我国自主研发了调查海底多金属硫化物的瞬变电磁设备,并于2011年6月在中国大洋第22航次第5航段中的大西洋中脊“贝利珠”热液区( 13.2°S、14.4°W)进行了试验,取得了我国首批海底热液区的瞬变电磁资料。本文对这批资料进行初步分析,阐述一种新的海底硫化物探测方法及其试用结果,得到的视电阻率断面与热液区的实际有很好的对应关系,从2条测线的实测结果来看,设备的探测深度达到海底面以下50~100 m。在本次试用过程中,较好验证了自主研发的深海瞬变电磁设备、获得的数据以及探测深度的可靠性。  相似文献   

IGSʵʱ��Ʒ�Ƚ������   总被引：2，自引：0，他引：2  

尹倩倩  楼益栋  易文婷 《大地测量与地球动力学》2012,32(6):123-128

????IGS????????????????????????????????????BKG??ESA??GFZ??GMV?????????????????????????IGS?o????????????ж??????????????????????RTN???????????????????????????????PANDA?????????IGS?????????????????ALBH???ж??PPP?????????λ?????????????  相似文献   

High mercury levels in hair samples from residents of Taiji, a Japanese whaling town     

Tetsuya Endo  Koichi Haraguchi 《Marine pollution bulletin》2010,60(5):743-747

We investigated the mercury concentrations in red meat from pilot whales consumed by some residents of the Japanese whaling town, Taiji, and in hair samples from 50 residents for their maker of mercury burden. The methyl mercury (M-Hg) level in the red meat was 5.9 μg/wet g, markedly higher than the US FDA action level and Cordex Alimentarius guideline level for predatory fish (1.0 μg/wet g). The average level of total mercury (T-Hg) in the hair from residents who ate whale meat more than once a month was 24.6 μg/g, whereas the average from the residents who did not consume any whale meat was 4.3 μg/g. The T-Hg concentrations in the hair from three donors exceeded 50 μg/g, the level for NOAEL set by WHO. The T-Hg level found in the Taiji whale meat consumers was markedly higher than that observed in the Japanese population overall (about 2 μg/g).  相似文献   

我国海洋水下观测网发展战略思考          下载免费PDF全文

罗续业  李彦 《海洋学研究》2016,34(3):1-5

海洋观测已呈现陆、海、空联合组网观测形式,这是海洋观测发展的必然趋势和未来走向。但我国在海洋水下观测能力方面极其薄弱,特别是与国际海洋发达国家相比存在较大差距,本文主要整理了国外水下观测网发展的有关政策、重点项目及技术装备,并对我国面临的海洋发展形势进行了分析,提出了我国海洋水下观测网发展战略建议,供有关管理人员和科研人员参考。  相似文献   

WorldView-2影像双介质摄影测量的浅海地形测绘试验     

曹斌  朱述龙  邱振戈  曹彬才 《遥感学报》2018,22(5):745-757

主要研究利用高分辨率WorldView-2卫星影像和双介质立体摄影测量方法进行浅海地形测绘的可行性,同时解决双介质立体摄影测量精定位算法(即折射改正算法)适用性差的问题。首先依据通用的双介质物像几何关系,提出了一种普适的双介质立体摄影测量折射改正算法;然后以海南省三沙市甘泉岛、珊瑚岛周围浅海区域为试验场,利用两个地区的WorldView-2立体影像,运用双介质立体摄影测量方法进行了浅海地形测绘试验。试验成功提取到了两个地区浅海海底的数字高程模型(DEM)。其中,甘泉岛地区的浅海DEM精度达到2.08 m(剔除其中的高程异常点后的结果)。研究表明:提出的折射改正算法,无论"空中同名光线延长线是否相交"都是适用的,且能改善浅海地形测绘精度。在水体清澈、无海浪情况下,利用相应的WorldView-2立体影像和双介质立体摄影测量方法进行浅海地形测绘是可行的。  相似文献   

小尺度地幔对流与海底地形抬升     

黄金水 《武汉大学学报(信息科学版)》2005,30(6):478-482

根据建立的垂直于大洋中脊的二维热对流有限元数值模型，采用常粘性以及与温度相关的粘性两种粘性结构对小尺度地幔对流对海底地形的影响进行了重新研究。该模型的主要特点是采用开放边界条件，从而可以避免原有封闭模型因回流问题而产生的复杂效应。数据结果显示，在常粘性模型中，小尺度地幔对流可造成海底地形抬升；但对与温度相关的粘性模型，小尺度对流对地形几乎不产生影响。  相似文献   

Gondwana breakup via double-saloon-door rifting and seafloor spreading in a backarc basin during subduction rollback   总被引：1，自引：0，他引：1  

A.K. Martin   《Tectonophysics》2007,445(3-4):245-272

A model has been developed where two arc-parallel rifts propagate in opposite directions from an initial central location during backarc seafloor spreading and subduction rollback. The resultant geometry causes pairs of terranes to simultaneously rotate clockwise and counterclockwise like the motion of double-saloon-doors about their hinges. As movement proceeds and the two terranes rotate, a gap begins to extend between them, where a third rift initiates and propagates in the opposite direction to subduction rollback. Observations from the Oligocene to Recent Western Mediterranean, the Miocene to Recent Carpathians, the Miocene to Recent Aegean and the Oligocene to Recent Caribbean point to a two-stage process. Initially, pairs of terranes comprising a pre-existing retro-arc fold thrust belt and magmatic arc rotate about poles and accrete to adjacent continents. Terrane docking reduces the width of the subduction zone, leading to a second phase during which subduction to strike-slip transitions initiate. The clockwise rotated terrane is caught up in a dextral strike-slip zone, whereas the counterclockwise rotated terrane is entrained in a sinistral strike-slip fault system. The likely driving force is a pair of rotational torques caused by slab sinking and rollback of a curved subduction hingeline.By analogy with the above model, a revised five-stage Early Jurassic to Early Cretaceous Gondwana dispersal model is proposed in which three plates always separate about a single triple rift or triple junction in the Weddell Sea area. Seven features are considered diagnostic of double-saloon-door rifting and seafloor spreading:

i) earliest movement involves clockwise and counterclockwise rotations of the Falkland Islands Block and the Ellsworth Whitmore Terrane respectively;

ii) terranes comprise areas of a pre-existing retro-arc fold thrust belt (the Permo-Triassic Gondwanide Orogeny) attached to an accretionary wedge/magmatic arc; the Falklands Islands Block is initially attached to Southern Patagonia/West Antarctic Peninsula, while the Ellsworth Whitmore Terrane is combined with the Thurston Island Block;

iii) paleogeographies demonstrate rifting and extension in a backarc environment relative to a Pacific margin subduction zone/accretionary wedge where simultaneous crustal shortening occurs;

iv) a ridge jump towards the subduction zone from east of the Falkland Islands to the Rocas Verdes Basin evinces subduction rollback;

v) this ridge jump combined with backarc extension isolated an area of thicker continental crust — The Falkland Islands Block;

vi) well-documented EW oriented seafloor spreading anomalies in the Weddell Sea are perpendicular to the subduction zone and propagate in the opposite direction to rollback;

vii) the dextral strike-slip Gastre and sub-parallel faults form one boundary of the Gondwana subduction rollback, whereas the other boundary may be formed by inferred sinistral strike-slip motion between a combined Thurston Island/Ellsworth Whitmore Terrane and Marie Byrd Land/East Antarctica.