A modeling study of seawater intrusion in Alabama Gulf Coast,USA   总被引：4，自引：0，他引：4  

Jin Lin  J. Blake Snodsmith  Chunmiao Zheng  Jianfeng Wu 《Environmental Geology》2009,57(1):119-130

A numerical model of variable-density groundwater flow and miscible salt transport is developed to investigate the extent of seawater intrusion in the Gulf coast aquifers of Alabama, USA. The SEAWAT code is used to solve the density-dependent groundwater flow and solute transport governing equations. The numerical model is calibrated against the observed hydraulic heads measured in 1996 by adjusting the zonation and values of hydraulic conductivity and recharge rate. Using the calibrated model and assuming all the hydrogeologic conditions remain the same as those in 1996, a predictive 40-year simulation run indicates that further seawater intrusion into the coastal aquifers can occur in the study area. Moreover, the predicted intrusion may be more significant in the deeper aquifer than the shallower ones. As the population continues to grow and the demand for groundwater pumping intensifies beyond the 1996 level, it can be expected that the actual extent of seawater intrusion in the future would be more severe than the model prediction. Better strategies for groundwater development and management will be necessary to protect the freshwater aquifers from contamination by seawater intrusion.

Jin LinEmail:

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Adsorption behaviour of dibutyl phthalate on marine sediments   总被引：1，自引：0，他引：1  

Xu XR  Li XY 《Marine pollution bulletin》2008,57(6-12):403-408

Laboratory experiments were carried out to investigate the adsorption behaviour of dibutyl phthalate (DBP) on marine sediments collected from five different sites in Victoria Harbour, Hong Kong. DBP adsorption can be well described by the Langmuir isotherm. The maximum DBP adsorption capacity (Q(max)) of the marine sediments ranges from 53 to 79 mg g(-1), which has a positive correlation with their organic content. Around 90% of the organic can be removed from the sediments with treatment by H(2)O(2) oxidation, and the Q(max) then decreases to a range between 13 and 22 mg g(-1). The black carbon content of the sediments has a much greater DBP adsorption capacity than does the natural organic matter of the sediments. The amount of DBP adsorbed on the sediments increases as the salinity of the marine water increases.  相似文献   

Adsorption of tributyltin by tributyltin resistant marine Pseudoalteromonas sp. cells     

Haruo Mimura  Ryusei Sato  Yuichi Furuyama  Akira Taniike  Masahiro Yagi  Kazutoshi Yoshida  Akira Kitamura 《Marine pollution bulletin》2008,57(6-12):877

The isolate, Pesudoalteromonas sp. TBT1, could grow to overcome the toxicity of tributyltin chloride (TBTCl) up to 30 μM in the absence of Cl⁻ in the medium until the cells reached an exponential phase of growth. The viability, however, was reduced after the cells reached a stationary phase. The degradation products, such as dibutyltin (DBT) and monobutyltin (MBT), were not detected in the growth medium, indicating that the isolate has no ability to degrade TBT into less toxic DBT and MBT. Up to about 10^7.5 TBT molecules were adsorbed by a single cell. The observation of morphological changes with an electron microscope showed that the cell surface became wrinkled after exposure to the lethal concentration of 10 mM TBTCl. These results indicate that the resistance of the isolate toward the toxicity of TBTCl is not related to the unique cell surface, which seems to play an important role in preventing the diffusion of TBTCl into the cytoplasm.  相似文献   

DIVERTING SEAWATER TO SCOUR THE ESTUARY-A QUEST FOR NEW APPROACH TO REGULATETHE LOWER YELLOW RIVER-     

Bingnan LIN  Jianjun ZHOU    Ren ZHANG 《国际泥沙研究》1999,(4)

1GENERALTraditionally,theLowerYellowRiverstartsatHuayuankouandrunsonaplainforabout800km,beforeemptyingintotheBohaiSea.Theriverisfedwithextremelyheavysedimentload(1.6billiontonsannuallyuptotheeighties)andrelativelysmallrunoff(46billionm3uptotheeighties)fromitsdrainagebasinupstream.Thisloadofsedimentispartlydepositedinthechannelresultinginaggradationorincreaseinthebedslope.TheremainderisdischargedtotheBobalSea.AsthetidesoftheBohaiSeaareweak,thedepositionintheareaaroundtherivermouthisusual…  相似文献   

海水中酚类有机物在粘土或沉积物上吸附特性的模拟研究   总被引：9，自引：0，他引：9  

杨桂朋 《海洋科学》1999,23(5):60-63

研究了海水中７种酚类有机污染物在粘土矿物及海洋沉积物上的吸附特征;发现了酚在粘土或沉积物上的吸附平衡常数与其水溶解度之间的线性自由能关系,。  相似文献   

向海洋要淡水解决沿海水荒问题探讨   总被引：2，自引：0，他引：2  

张云吉  金秉福 《海洋湖沼通报》1999,(2):60-64

我国沿海地区淡水资源匮乏,供需矛盾尖锐,大力发展低能耗的海水淡化技术,开发海底淡水资源,是沿海地区解决水荒问题的两个重要措施。  相似文献   

海(咸)水入侵与浅层地下水水化学特征及变化研究   总被引：9，自引：1，他引：8  

赵建 《地理科学》1999,19(6):525-531

利用山东莱州湾沿岸海水入侵监测剖面的水化学监测数据,从水化学指标与Ｃｌ＾－含量的关系入手,采用不同侵染程度组段钭所选定的水化学指标对Ｃｌ＾－含量作回归分析的方法,对海水入侵过程中浅层一上水水化学特征变化作了研究。研究表明,多数水化学指标及几项灌溉水质指标与侵染程度有较明显的宏观相关性,但不是简单的线性关系,两个剖面分析数据的对比揭示出莱州湾东部与南部沿岸海水入侵的区域差异性。  相似文献   

硫酸盐还原菌对海水状态和碳钢腐蚀行为的影响   总被引：4，自引：0，他引：4  

严莉  王佳 《海洋科学》2004,28(9):70-74

采用溶液环境参数和电极电化学参数测量技术研究了海水中硫酸盐还原菌生长和衰亡过程对溶液状态和D36碳钢腐蚀过程的影响。结果表明,硫酸盐还原菌通过新陈代谢作用把溶液中的硫酸盐转化为硫离子而增大了氧化还原电位和酸度,并导致D36钢的腐蚀电位负移和腐蚀速度增加。极化曲线和电化学阻抗谱证实,虽然金属腐蚀过程在上述过程中并未发生机理性变化,但阳极过程和部分阴极过程的加速是腐蚀速度增加的主要原因。上述结果同时表明．硫酸盐还原菌本身和新陈代谢中间体并未直接参与腐蚀过程,主要是通过产生的硫离子改变溶液状态来加速腐蚀过程的。  相似文献   

海洋生态环境承载能力评价方法验证及建议 ——以浙江省近岸海域为例          下载免费PDF全文

陈思杨  李尚鲁  宋琍琍  刘瑞娟  余骏  刘希真 《海洋开发与管理》2021,38(4):84-90

为推动海洋资源的合理开发和有效保护,文章采用《资源环境承载能力监测预警技术方法(试行)》(《技术方法》)开展浙江省近岸海域海洋生态环境承载能力评价试点研究,验证指标体系和评价方法的适用性并提出建议。研究结果表明:《技术方法》的海洋环境承载状况评价结果更多代表氮磷水平,不足以客观反映海洋环境承载状况,而适应性验证方法的评价结果总体略好;海洋生态承载状况评价的适应性验证方法增加浮游植物参数,并以区域5年均值为基准,所得结果更为合理。针对《技术方法》的适用性问题以及业务化应用和管理的需求,建议:评价指标和具体参数的设置应考虑区位特点和自然属性,在海洋生态承载状况评价参数中增加浮游植物,并加长区域基准值的时间跨度;在集成评价时对指标设置较为合理的权重系数;加强中小尺度海洋生态环境承载能力研究;强化海洋生态环境承载能力评价与监测预警的结合应用。该研究成果可为进一步完善国家海洋生态环境承载能力监测预警工作提供技术支撑。  相似文献   

Simulation of chloride migration rates in Paleo Pennar Delta Region, Coastal Andhra Pradesh, India   总被引：1，自引：0，他引：1  

M. V. R. Chowdary  I. Radhakrishna 《Environmental Geology》1998,36(1-2):109-117

 Quaternary alluvial aquifers in the paleo Pennar delta region of Andhra Pradesh (Long. 80°0′ and 80°12′; Lat. 14°40′ and 14°20′) constitute an important coastal strip, with potential fresh groundwater resources and several well fields in operation. The lineament patterns and traces of paleo channels provide basic information on the configuration and boundaries of paleo delta and the possible neotectonic movements in the region. The paleo delta region is essentially characterized by freshwater aquifer systems at the near-surface depths, (up to 50 m from ground level) with transmissivity values in the system ranging from 1200 to 2500 m²/day. This groundwater system has been subjected to heavy draft situation over the last two decades, parlicularly near the outer rim of the delta where an unlined brackish-water canal runs parallel to the coast imparting chloride contamination to the adjoining fresh aquifers. A two-dimensional solute transport model solution was applied to assess chloride migration rates inland under different hydraulic stresses, combining finite difference solution of flow equation and the method of characteristic solution of solute transport equation. Groundwater flow and chloride migration patterns/rates were obtained for different simulated stress events in the delta system, and measures required to protect the freshwater resources ara outlined. Received: 2 January 1997 · Accepted: 4 November 1997  相似文献