Kinetic and equilibrium studies of copper-dissolved organic matter complexation in water column of the stratified Krka River estuary (Croatia)     

Yoann Louis  Cdric Garnier  Vronique Lenoble  Stphane Mounier  Neven Cukrov  Dario Omanovi&#x;  Ivanka Pieta 《Marine Chemistry》2009,114(3-4):110-119

An interaction of dissolved natural organic matter (DNOM) with copper ions in the water column of the stratified Krka River estuary (Croatia) was studied. The experimental methodology was based on the differential pulse anodic stripping voltammetric (DPASV) determination of labile copper species by titrating the sample using increments of copper additions uniformly distributed on the logarithmic scale. A classical at-equilibrium approach (determination of copper complexing capacity, CuCC) and a kinetic approach (tracing of equilibrium reconstitution) of copper complexation were considered and compared. A model of discrete distribution of organic ligands forming inert copper complexes was applied. For both approaches, a home-written fitting program was used for the determination of apparent stability constants (K_i^equ), total ligands concentration (L_iT) and association/dissociation rate constants (k_i¹,k_i^- 1).A non-conservative behaviour of dissolved organic matter (DOC) and total copper concentration in a water column was registered. An enhanced biological activity at the freshwater–seawater interface (FSI) triggered an increase of total copper concentration and total ligand concentration in this water layer. The copper complexation in fresh water of Krka River was characterised by one type of binding ligands, while in most of the estuarine and marine samples two classes of ligands were identified. The distribution of apparent stability constants (log K₁^equ: 11.2–13.0, log K₂^equ:8.8–10.0) showed increasing trend towards higher salinities, indicating stronger copper complexation by autochthonous seawater organic matter.Copper complexation parameters (ligand concentrations and apparent stability constants) obtained by at-equilibrium model are in very good accordance with those of kinetic model. Calculated association rate constants (k₁¹:6.1–20 × 10³ (M s)^− 1, k₂¹: 1.3–6.3 × 10³ (M s)^− 1) indicate that copper complexation by DNOM takes place relatively slowly. The time needed to achieve a new pseudo-equilibrium induced by an increase of copper concentration (which is common for Krka River estuary during summer period due to the nautical traffic), is estimated to be from 2 to 4 h.It is found that in such oligotrophic environment (dissolved organic carbon content under 83 µM_C, i.e. 1 mg_CL^− 1) an increase of the total copper concentration above 12 nM could enhance a free copper concentration exceeding the level considered as potentially toxic for microorganisms (10 pM).  相似文献   

Tapered Suction Caissons： A Numerical Investigation into Their Pull-out Performance   总被引：1，自引：0，他引：1  

M. Zeinoddini  J. Keyvani  M. Nabipour 《中国海洋工程》2009,23(4):695-707

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Simplified Calculation Method and 3D Numerical Analysis for Pile Group Under Uplift Loading     

孔纲强  杨庆  刘汉龙  栾茂田 《中国海洋工程》2009,23(4):709-718

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COMCOT数值模式的介绍和应用   总被引：1，自引：0，他引：1  

潘文亮  王盛安 《海洋预报》2009,26(3):45-52

介绍了一个成熟的海啸数值模式-COMCOT模式.COMCOT模式是一个能够模拟海啸产生、传播和增水全过程的基于浅水波方程的有限差分模型.模型采用多层网格嵌套,根据海啸在不同区域的传播特点和要求,分别选用不同的分辨率和计算设置,从而兼顾了模式的精度和计算效率.利用此模式模拟了2006年12月26日台湾南部7.2级地震产生海啸波的传播情况,结果与两个潮位站的海啸波监测数据相吻合.  相似文献   

台风作用下淤泥质海岸动力地貌响应   总被引：6，自引：0，他引：6  

戴志军  张小玲  闫虹  李九发  恽才兴 《海洋工程》2009,27(2):63-69

基于200509号麦莎台风(近似百年一遇)作用前后杭州湾北岸龙泉-南竹港实测的海岸地形和水文资料,利用分形技术、冲刷深度和闭合水深等相关概念分析淤泥质海岸的剖面变化、岸线进退以及地形冲淤,进而探讨海岸响应台风作用的动力地貌行为.结果表明:1)台风作用前后的海岸动力地貌过程表现为水下类似沙坝的堆积体削平、凹处填洼,水下平台发育锯齿或较小的坝--槽,海岸剖面的分维数降低,剖面坡度处于平缓;2)麦莎台风对海床的整体冲淤幅度不大,这可能是由于研究区大潮讯的增水致使波浪对海床的塑造能力减弱以及码头的遮蔽作用造成;3)台风作用对海岸的冲刷深度约为0.8 m,闭合水深为9.5 m,近岸-1 m邻近区成为海岸响应台风作用最敏感的地带;泥沙主要在0 m到闭合水深区间的海床发生纵、横向运移.  相似文献   

Fuzzy comprehensive evaluation model for water resources carrying capacity in Tarim River Basin, Xinjiang, China   总被引：12，自引：0，他引：12  

Lihong Meng  Yaning Chen  Weihong Li  Ruifeng Zhao 《中国地理科学(英文版)》2009,19(1):89-95

This paper explores the method of comprehensive evaluation of water resources carrying capacity and sets up an evaluation model applying the fuzzy comprehensive evaluation method. Based on the data of nature, society, economics and water resources of the Tarim River Basin in 2002, we evaluated the water resources carrying capacity of the basin by means of the model. The results show that the comprehensive grades are 0.438 and 0.454 for Aksu and Kashi prefectures respectively, where the current water resources exploitation and utilization has reached a relative high degree and there is only a very limited water carrying capacity, 0.620 for Kizilsu Kirgiz Autonomous Prefecture, where water resources carrying capacity is much higher, and in between for Hotan Prefecture and Bayingolin Mongolian Autonomous Prefecture. As a whole, the comprehensive grade of the Tarim River Basin is 0.508 and the current water resources exploitation and utilization has reached a relative high degree. Thus, we suggest that the integrated management of the water resources in the basin should be strengthened in order to utilize water resources scientifically and sustainably.  相似文献   

Causes of rockfalls in Al-Huwayshah area,Yemen     

Aref M.O.AL-JABALI  Abdo S.AL-MAQTARY  Hussein AL-AKHALI  Mohammed HAZAEA  Fadel AL-AGHBARI 《东北亚地学研究》2009,(1)

According to topography of Yemen,most areas and villages are located at obligated crest,toe of mountain and under cliffs.Therefore Al-Huwayshah consisting of Tawilah sandstone group is characterized by steep slope reach to 90° in some areas.This area is affected by strong tectonic movements and faults that occurred during the geological epochs.This effect enhances to find out fractures and joints as well as the rocks become brittle and ready to slide depending on the position of area.And there are some frac...  相似文献   

四川汶川“5.12”地震滑坡堰塞湖遥感监测分析   总被引：5，自引：0，他引：5  

潘世兵  李小涛  宋小宁 《地球信息科学学报》2009,11(3):299-304

运用可见光、雷达和航片等不同空间分辨率的多源遥感数据,对四川汶川"5.12"地震灾区因地震诱发形成的大型堰塞湖进行了遥感监测,对堰塞湖发生的地点、数量以及空间分布规律进行了讨论。重点对唐家山堰塞湖进行了动态监测,提取了其堰塞湖回水长度、水面面积与水量等信息,并对这一结果进行了详细分析,为地震滑坡堰塞湖科学处置与减灾决策提供了科学依据。  相似文献   

基于非线性动力学模型的旅游生态容量分析   总被引：1，自引：0，他引：1  

吕龙  黄震方  吴江 《地球信息科学学报》2009,11(2):163-168

近年来,大量增加的游客给景区的旅游生态容量带来了较大的压力,矛盾日渐突出。为了实现景区的环境保护与可持续发展,研究游客活动量与景区旅游生态容量之间的关系是十分必要的。本文从非线性动力学观点出发,构建二者非线性动力学模型,并进行平衡态分析。研究结果表明:(1)系统要达到可持续发展,必须建立在景区环境的自我更新能力及人工恢复程度之和大于外界污染水平,且游客的增长率必须保持在较低水平的基础上;(2)景区旅游生态容量的承载力是有限的,所能容纳的游客也是有限的,超过一定的限度就会引起生态系统失衡。采取严格控制游客量,加强对景区内外环境的保护和改善、提升游客素养等措施,对于系统的协调发展至关重要。  相似文献   

基于公平性的水环境容量分配研究——以沱江流域为例   总被引：1，自引：0，他引：1  

钱骏  廖瑞雪  佟洪金  蒋厦  薛基瑜 《成都信息工程学院学报》2009,24(1)

公平与效益是容量分配的两个重要原则.在我国目前采用的水环境容量无偿分配方式下,公平原则是需遵循的首要原则,在公平的基础上追求效益.以沱江流域为对象,综合考虑涉及区域的社会、经济、自然等客观因素,筛选指标确定系数对流域容量进行分配.应用经济学中衡量收入公平的基尼系数概念,对分配结果的公平性进行评估,给出综合体现社会性、经济性和历史性的水环境容量分配方案.  相似文献