海水中微量无机离子的气相色谱测定的研究     

崔仙舟  尹相淳 《海洋湖沼通报》1995,(3):32-38

本文讨论了介绍了用气相色谱法测定海水中无机离子Ｓｅ（－Ⅱ，Ｏ，Ⅳ，Ⅵ）；Ｂｅ（Ⅱ）；Ｃｒ（Ⅲ，Ⅳ）；ＣＨ３Ｈｇ＾＋，ＮＯ３，ＮＯ２，Ｂｒ，Ｉ，ＣＮ的测定方法和色谱条件。  相似文献   

An improved method for mapping tidal waterways based on remotely sensed waterlines: A case study in the Yellow River Delta,China     

Xiang Yu  Chao Zhan  Mengquan Wu  Xueli Niu  Xueyu Zhang 《Marine Georesources & Geotechnology》2020,38(8):887-895

Abstract

Tidal waterways perform as the paths through which seawater invades. Their spatial-temporal variation with the shift in Yellow River’s route requires the accurate measurement of their status. Visual interpretation for delineating tidal waterways is inefficient due to a substantial amount of work. Buffer analysis provides an alternative to visual interpretation. However, it is difficult to use the buffer distance threshold to identify tidal waterways from other freshwater bodies. In this study, we present a straightforward method for mapping tidal waterways. First, we adopted the normalized difference water body index (NDWI) to extract water bodies. Waterlines were subsequently delineated based on a morphological opening filter with a kernel of 9?×?9. Finally, tidal waterways were mapped based on the proposed topological relation in ArcGIS. We showed the utility of this approach by mapping tidal waterways in the Yellow River Delta, China. The proposed method enables tidal waterways be mapped precisely and was replicable and universal in other similar studies.  相似文献   

北黄海水中辐照度的分布变化特征     

李武  张士魁  吴曙初  辛海英 《海洋科学进展》1997,(2)

本文对北黄海５次现场调查中获得的水中辐照度资料，应用统计分析方法，建立辐照度随水深变化的关系模式，分析辐照度的垂直衰减特性。结果表明：辐照度随水深按指数函数规律衰减；辐照度垂直衰减系数Ｋ有明显的季节变化和区域特征；不同水层的Ｋ值各不相同，Ｋ的变化存在分层结构。  相似文献   

海水及天然水中微量碘离子快速测定法的研究     

崔仙舟  王中柱 《海洋与湖沼》1995,26(6):673-677

研究用气相色谱测定海水及天然水中微量碘离子含量的快速分析方法，确定了最佳条件。水样经酸化后，用Ｋ２Ｃｒ２Ｏ７将碘离子氧化成碘，再与丁酮反应的１０ｍｉｎ，生成磺代丁酮，用环己烷萃取后，用气相色谱仪的电子捕获检测器测定其含量。于１９９１年６月，用此法测定青岛胶州湾沿岸海水及某些河口水样，证明该方法简便、快速。  相似文献   

海上溢油的处置     

吴雯 《海洋科学进展》1997,(3)

全世界每年流入海洋的石油多达数百万吨，超过了海洋的自净能力，造成污染。本文综述了海上溢油的处置技术，包括石油入海后的处理和回收技术以及海上溢油的最终处置技术。  相似文献   

Boron isotopic fractionation during seawater evaporation   总被引：6，自引：0，他引：6  

Y.K. Xiao  S.Z. Li  H.Z. Wei  A.D. Sun  W.G. Liu  W.J. Zhou  Z.Q. Zhao  C.Q. Liu  G.H. Swihart 《Marine Chemistry》2007,103(3-4):382-392

Laboratory experiments were undertaken to investigate the behaviour of boron at the seawater–air interface during seawater evaporation. Seawaters adjusted to different pH values were heated to 27, 33 and 40 °C inside a quartz evaporator. The vapor was collected with a quartz condenser using a cold trap. A natural seawater–vapor process in quiet air conditions and excluding the sea-spray component was realized using this arrangement. The results indicate an enrichment of ¹¹B in the condensate. This implies that in the natural environment, rainfall with δ¹¹B values lower than that of seawater has been affected either by continental boron sources or by the boron extracted from seawater under airflow conditions. While the net flux of boron carried away from the ocean by air masses due to seawater evaporation is significant compared to other fractionation-associated processes removing boron from the ocean, the effect of isotopic fractionation as boron enters the vapor phase on the isotopic composition of boron in the ocean over time is small.  相似文献   

Dissociation constants of protonated methionine species in seawater media     

Virender K. Sharma  Frank J. Millero  Concetta De Stefano  Pasquale Crea 《Marine Chemistry》2007,106(3-4):463-470

The dissociation constants (pK₁ and pK₂) for methionine have been measured in artificial seawater as a function of salinity (S = 5 to 35) and temperature (5 to 45 °C). The seawater pK₂ values were lower than the values in NaCl at the same ionic strength while the pK₁ values in seawater were lower only at S = 35. In an attempt to understand these differences, we have made measurements of the constants in Na–Mg–Cl solutions at 25 °C. The measured values have been used to determine the formation of Mg²⁺ complexes and Pitzer interaction parameters for Mg²⁺ with methionine. The seawater model with the interaction parameters accounts for the differences between the value of pK₁ and pK₂ between NaCl and seawater. This study demonstrates that it is important to consider all of the ionic interactions in natural waters when examining the dissociation of organic acids.  相似文献   

Geoelectrical and hydrogeochemical studies for delineating seawater intrusion in the outlet of Wadi Ham, UAE   总被引：2，自引：0，他引：2  

M. Sherif  A. El Mahmoudi  H. Garamoon  A. Kacimov  S. Akram  A. Ebraheem  A. Shetty 《Environmental Geology》2006,49(4):536-551

The Quaternary aquifer of Wadi Ham, UAE has been overexploited during the last two decades to meet the increasing water demands. As a result, the dynamic balance between freshwater and seawater has been disturbed and the quality of the groundwater has deteriorated. In this paper, a 2D earth resistivity survey was conducted in Wadi Ham in the area between Fujairah and Kalba to delineate the seawater intrusion. Existing monitoring wells were used to measure the horizontal and vertical variations in water salinity and thus to improve the interpretation of earth resistivity imaging data. Results of vertical electrical soundings and chemical analyses of collected water samples were used to obtain an empirical relationship between the inferred earth resistivity and the amount of total dissolved solids. This relationship was used along with the true resistivity sections resulting from the inversion of 2D resistivity data to identify three zones of water-bearing formation (fresh, brackish, and salt-water zones). Along the four 2D resistivity profiles, the depth to the fresh-brackish interface exceeded 50 m at the western part of the area and was in the order of 10 m or less in the eastern side near the shoreline. Depth to the brackish-saline water interface reached about 70 m in the western side and was in the order of 20 m in the eastern side. The thickness of the fresh water zone decreases considerably in the farming areas toward Kalba and thus the degree of seawater intrusion increases.  相似文献   

The use of bromide and chloride mass ratios to differentiate salt-dissolution and formation brines in shallow groundwaters of the Western Canadian Sedimentary Basin     

James T. Freeman 《Hydrogeology Journal》2007,15(7):1377-1385

In the Western Canadian Sedimentary Basin, the petroleum industry handles two geochemically distinctive brines that are traceable in the environment: formation brines extracted along with hydrocarbons from the basin, and salt-dissolution brines, produced by dissolving deep halite formations to create caverns for petroleum product storage. The concentrations of the conservative ions chloride (Cl) and bromide (Br) in many formation brines plot closely to the seawater evaporation trajectory of previous studies. These brines contain Cl/Br mass ratios of around 300, while salt-dissolution brines are relatively Br depleted, having Cl/Br mass ratios in excess of 20,000. An oilfield site in central Alberta had experienced nearby releases of both salt-dissolution and formation brines. Geochemical mixing trends were defined by theoretically mixing samples of local salt-dissolution and formation brine sources with background shallow groundwater. Most site monitoring wells and local surface water samples plotted directly on a salt-dissolution brine dilution trend, while results from four monitoring wells, all located directly downgradient of formation brine spills, suggested the mixing of formation brines into shallow groundwater. This work indicates that there is a large-scale salt-dissolution brine plume beneath the site and reinforces the use of Cl and Br concentrations and mass ratios as environmental tracers.  相似文献   

Status of butyltin pollution along the coasts of western Japan in 2001, 11 years after partial restrictions on the usage of tributyltin     

Murai R  Takahashi S  Tanabe S  Takeuchi I 《Marine pollution bulletin》2005,51(8-12):940-949

Restrictions on the use of tributyltin (TBT) in aquaculture and on boats in coastal regions, except for ocean-going vessels, have been in place in Japan since 1990 due to the strong toxic effects of TBT on marine organisms. However, TBT pollution along the Japanese coasts has been reported after this legislation was enacted. In order to elucidate the present status of contamination by butyltin (BT) compounds, we measured the levels of BTs [monobutyltin (MBT), dibutyltin (DBT) and TBT] in seawater and Caprella spp. samples obtained from the western part of Seto Inland Sea, Uwa Sea and Uranouchi Bay in western Japan during March to September, 2001. Butyltins were detected in more than 90% of the seawater samples (n = 59), with average concentrations of 8.2 ± 9.2 (SD) ng MBT L⁻¹, 3.3 ± 3.0 ng DBT L⁻¹ and 9.0 ± 7.0 ng TBT L⁻¹. Among 41 stations situated on coastal lines, a sufficient number of Caprella organisms for chemical analysis could be collected from only 16 stations. The butyltin concentrations in seawater and Caprella samples from Uwa Sea and Uranouchi Bay, in which the dominant industry in both waters is aquaculture, showed significantly higher than or no significant differences from those samples from the western part of Seto Inland Sea, a major heavy-industry area in Japan. As the TBT concentration in seawater increased, the number of Caprella organisms collected decreased. The mean TBT concentration among the seawater samples was above the estimated lowest observable effect concentration (LOEC) that reduces the survival rate of Caprella danilevskii. Thus, the present study indicates that TBT is still a potential ecological hazard to the survival of marine invertebrates inhabiting coasts along western Japan, even 11 years after the partial ban on TBT usage was implemented.  相似文献