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1.
Photochemical degradation of crude oil in seawater   总被引:2,自引:0,他引:2  
1 INTRODUCTION Marine photochemistry is a newly developed subject in marine sciences. Photochemical degrada- tion is important in decomposing and removing various organic contaminants in oceans (Ali et al., 1995a, b; Yang, 2000; Yang and Qi, 2002; 2003). …  相似文献   

2.
Ground water samples from several private wells serving individual homes in Tiverton, Rhode Island were analyzed for petroleum contamination over a 19-month period. The hydrocarbon concentrations initially ranged from 68 to 2350 ppb and then gradually decreased to lower values, ranging from 6 to 1650 ppb, at the end of the study. Samples from the well with the highest hydrocarbon concentration (2350 to 1650 ppb) were investigated in some detail because this was considered a possible source of the petroleum contamination in the area. These studies indicated that most of the hydrocarbons were in the dissolved phase (<1.0 μm) of the ground water and that it contained large amounts of naphthalene, methyl and dimethyl naphthalenes, and ethyl naphthalenes. In addition, the qualitative distribution of hydrocarbons changed as the concentration decreased over the course of the investigation. There appeared to be preferential loss of the more volatile and easily degraded components relative to the higher molecular weight and more refractory hydrocarbons. Some of the wells at this location are contaminated with at least two different petroleum products, i.e. gasoline and fuel oil. The exact nature and source of the contaminant is not known; it may be spilled or leaking petroleum products, or other materials containing petroleum hydrocarbons (e.g. commercial or industrial cleaning solutions). Based on differences in the qualitative distribution of components, some of the wells contain hydrocarbons that have been environmentally altered or that originate from a source other than the most contaminated well  相似文献   

3.
在沿海地区划分海水入侵界线具有重大意义,在海水入侵范围内,地下水由于含盐量高,虽然工业生产、人畜生活不能利(饮)用,但深部海水可为海产品养殖业带来较高的利用价值。利用高密度电法和可控源音频大地电磁2种方法准确划分了浅、深部海水入侵界线,并根据电性特征分析探讨了海水入侵区域的由浅至深的侵入特点,推测了不同深度上岩石破碎及富水规律,为探讨沿海养殖业利用温度相对稳定或较高的深部入侵海水进行了积极、有益的探讨。  相似文献   

4.
石油污染物的微生物降解   总被引:8,自引:0,他引:8  
从炼油厂污水池底泥中富集、驯化、分离、筛选,得到4种优势石油降解菌。采用摇床培养,研究了各优势菌和混合菌对石油烃的降解性能。结果表明:4种菌和混合菌20 d可将初始质量浓度为10000 mg/L的石油烃依次降解90.8%、88.9%、57.8%、49.8%、91.2%;培养液中石油烃的半衰期依次为5.5、6、15、19、5 d。初步鉴定4种菌分别属:节细菌(Arthrobacter sp.)、芽胞杆菌(Bacillus sp.)、不动杆菌(Acinetobacter sp.)、不动杆菌(Acinetobacter sp.)。  相似文献   

5.
The southern coast of Laizhou Bay, Bohai Sea, is one of the areas in China most seriously impacted by seawater intrusion. Based on the sources of intruding waterbedies, seawater intrusion can be divided into two types: intrusion of saline water derived from modern seawater, and intrusion of subsurface brine and saline water derived from paleo-seawater in shallow Quaternary sediments. There are some distinct differences in their formation, mechanism and damage. The subsurface brine intrusion is a special type, which can cause very serious disaster. The coastal landform and the Quaternary hydrogeological environment are predominant factors in the classification of seawater intrusion types. Various coastal environments in different coastal sections result in three types of intrusion: seawater intrusion, saline groundwater intrusion, and mixed seawater and saline water intrusion, in the southern coast of Laizhou Bay, which can be divided into four areas: the sea-water intrusion area in the northern Laizhou City coast, the mixed seawater and saline groundwater intrusion area in the Baisha River-Jiaolai River mouth plain area, the mixed seawater and saline groundwater intrusion area in the Weihe River mouth plain area northern Changyi county coast, and the saline ground-water intrusion area in the northern Shouguang plains.  相似文献   

6.
Accumulation and distributions of aliphatic and polyaromatic hydrocarbons (PAHs) and heavy metals were measured in tissues of the clam Ruditapes philippinarum collected from 5 sites in Jiaozhou Bay, Qingdao, China. The concentrations of total aliphatic hydrocarbon and PAHs ranged from 570 to 2 574 ng/gdw (gram dry weight) and from 276 to 939 ng/gdw, in the most and least polluted sites, respectively. The bio-accumulation of hydrocarbons and PAHs in the clams appeared to be selective. Aliphatic hydrocarbons were predominantly represented by short chain (<nC23) n-alkanes, suggesting that petroleum hydrocarbons were likely the major contamination source. The selective uptake of 3 and 4 ring PAHs, such as naphthalene, fluorene, phenanthrene, fluoranthene and pyrene, by the clams was probably related to the physiological and bio-kinetic processes that were energetically favorable for uptake of compounds with fewer rings. Accumulation of the metals Cd, Cu, Zn, Pb, Cr, Hg, and As in the clam tissues also showed high variability, ranging from 0.043 to 87 μg/gdw. Among the 7 detected metals, Zn, Cd, Cu, and As had a particularly high potential of accumulation in R. philippinarum. In general, a positive correlation was found between the tissue concentrations and sediment concentrations of hydrocarbons and of some metals. Our study suggests that moderate contamination with polyaromatic hydrocarbons, and low to moderate contamination with metals, currently exists for clam R. philippinarum in Jiaozhou Bay, in comparison with other regional studies. A long-term monitoring program is certainly needed for assessment of the potential ecological influence and toxicity of these contaminants of R. philippinarum in Jiaozhou Bay.  相似文献   

7.
Beachrocks like those in Haishan Island’s “beachrock field” are rarely found elsewhere. They contain typical cement-aragonite. The assemblages of foraminifera and ostracods show that they are typical littoral sediments, the middle and the lower beds of beachrocks being formed in the desalinized seawater, the upper bed in normal seawater. At least four coastal elevations and subsidences have occurred since Late Holocene. The amplitude of the last three subsidences increased each time and the sea coasts receded. Active elevation has been predominant since 600 years B.P. Periodical coastal elevation and subsidence in Fujian and Guangdong has been occurring for the past several thousand years. Each period was 500 years, 250 years of subsidence, 250 years of elevation. This study was financed by the Department of Science and Technology of the State Seismological Bureau and the Joint Seismological Science Foundation.  相似文献   

8.
Chemical means were used to extract polyphenols from healthy brown algae collected in littoral seawater. Experiments on corrosion of A3 steel, the time-potential curve, and polarization curve in polyphenols seawater showed stronger cathodic polarization compared with that in common seawater. This indicates that brown algae polyphenols might feasibly be used as corrosion inhibitor in seawater. Contribution No. 3763 from the Institute of Oceanology, Chinese Academy of Sciences. Project 59471054 supported by NSFC and National “Nineth Five Year” Project 96-916-04-01.  相似文献   

9.
Surface sediment and seawater samples were collected from coastal areas around Okinawa Island from September 2001 to May 2002. The samples were analyzed for total polychlorinated biphenyl (PCB) levels and homolog composition. The results show that total PCB levels ranged from 0.32 to 128.7 ng/g (dry wt.) in sediment and 1.59 to 2.48 ng/L in seawater. The levels exceed the Environmental Quality Standard (EQS) for water pollution of Japan. The distribution of PCB homolog showed different patterns in the sediments and seawaters. Penta-chlorobiphenyls (CBs) comprised the main congener group in seawater, while hexa-CBs were more abundant homologs in the sediments. The heavily contaminated sites featured higher CBs, including penta-CBs, hexa-CBs, and hepta-CBs, than those in less contaminated sites where tri-CBs dominated. This study provides current distribution and geochemical behavior of PCBs in the coastal areas around Okinawa Island.  相似文献   

10.
滨海平原弱透水层广布且多赋存古咸水,其盐度分布及运移过程深刻影响着含水层地下水的演变,却得到甚少关注。采集了江苏滨海区7个浅层钻孔弱透水层原状样品,压榨法收集孔隙水。利用孔隙水天然示踪剂ρ(Cl-),ρ(Br-)剖面和数值模拟分析了弱透水层孔隙水盐度特征和运移机制。得出浅层孔隙水ρ(Cl-)垂向剖面存在2个趋势:①峰值在表层,沿深度逐渐下降;②峰值在深度25m左右,向两端浓度降低。孔隙水ρ(Cl-)为486.2~38 036.7 mg/L,Cl/Br比值为72~360(均值241)。ρ(Cl-)与Cl/Br比值关系及剖面分布说明孔隙咸水为海相成因,来自于全新世海侵时期的古海水,并受到后期淡水的稀释。弱透水层孔隙水一维垂向运移数值模型表明海侵-海退事件控制了海岸带弱透水层孔隙水的盐度演变,全新世古海水仍封存在沉积物中,更新世时期的海水已被驱替。孔隙水运移以扩散为主,垂向运移速率为0.43~15.8 mm/Ma。在相对高渗透性的粉砂地层中,可能还受到侧向对流的影响。弱透水层中古海咸水的重新分布,尤其在地下水超采条件下,可能成为地下水的重要咸化来源。   相似文献   

11.
南海北部鱼类石油烃含量地理差异原因浅析   总被引:1,自引:0,他引:1  
比较了南海北部海洋鱼类石油烃含量的地理差异,结果表明:被研究的5个海区中,广州湾海洋鱼类的石油烃含量明显高于北部湾(p<0.05)和红海湾(P<0.05),该3个海区和珠江口明显高于台湾浅滩(p<0.01),其余的两两之间没有统计学差异(p>0.05)。利用海洋环境质量调查和监测资料进行分析,说明这种地理分布特征与南海北部近岸海域的石油烃污染有直接关系。  相似文献   

12.
Growth of phytoplankton, zooplankton and probably most other marine organisms as well, is likely to be affected by the pH of seawater. Growth of calcareous shells and skeletons is less likely to be affected by the saturation states of calcite and aragonite but the dissolution is. The increase of CO2 in the oceans due to burning of fossil fuel and clearing of forests is decreasing the pH of seawater and the degrees of saturation for calcite and aragonite wordwide. This paper presents the results of the first attempt to estimate the vertical distribution of anthropogenic CO2, and the decreases in pH and the degrees of saturation of calcite and aragonite in seawater near Taiwan. Most effects are very small except for the possible dissolution of aragonite on the upper continental slope starting around 2050 AD.  相似文献   

13.
This study on the sectional and vertical distribution of dissolved oxygen (DO) and the O2 fluxes across the sea-air interface in East China Sea (ESC) waters shows that the waters were in steady state and that the difference of DO was great in upper and bottom waters in Apr. 1994; but that seawater mixing was strong and the difference of DO was small in upper and bottom waters in Oct. 1994. The above conclusions were specially obvious in continental shelf waters under 100 m. The DO maximum in subsurface layer waters appeared only at several stations and in general the DO in the waters decreased with depth. The horizontal distributions of O2 fluxes across the sea-air interface appeared in stripes in Leg 9404 when most regions covered were supersaturated with O2 seawater to air flux was large, and that on section No. 1 was 1.594 L/m2·d. The horizontal distribution of O2 fluxes across the sea-air interface appeared lumpy in Leg 9410, when most regions covered were unsaturated with O2·O2 was dissolved from air to seawater, and the fluxes were 0.819 L/m2·d on section No. 1 in Leg 9310, 0.219 L/m2·d in Leg 9410. The main reasons for DO change in surface layer seawater were the mixture of upper and bottom layer water, and the exchange of O2 across the sea-air interface. The variation of DO by biological activity was only 20% of total change of DO. Contribution No. 2716 from Institute of Oceanology, Chinese Academy of Sciences.  相似文献   

14.
于2005年8月对湛江港附近海域潮间带的海水、表层沉积物和贝类体内的重金属进行了分析,结果表明:海水中的砷优于海水水质Ⅰ类标准,而汞、铜、锌、铅、镉均有不同程度的污染,其中铜、铅、镉污染较为严重,均劣于海水水质Ⅳ类标准;表层沉积物中砷的含量低于全国海岸带背景值,而汞、铜、锌、铅、镉均高于全国海岸带背景值,其标准指数分别为1.35、1.66、1.50、2.08、3.10,汞、铜略高于海洋沉积物质量标准第一类标准,有轻微污染,砷、锌、铅均低于海洋沉积物质量标准第一类标准,未受污染,而镉略高于海洋沉积物质量标准第二类标准,环境受镉污染。各元素在各站点的分布没有规律性。牡蛎和蛤仔体内各重金属含量均优于海洋生物污染评价标准和人体消费卫生标准,其卫生质量良好。  相似文献   

15.
海岸带是地球表层物质、能量和信息流通交换最活跃区域之一,具有动态变化的盐度、溶解氧等地球化学梯度,其界面过程体现在大气降水-河水-海水-地下水-沉积物之间的物质循环和能量交换。在人类活动与气候变化双重影响下,海岸带面临着气候灾害、海岸侵蚀、海水入侵、滨海湿地退化、水体富营养化以及重金属、新型污染物等生态环境问题,成为地球科学和环境科学领域研究的热点。本文围绕海岸带水文-生物地球化学循环、人类活动影响下的海岸带环境问题、海岸带环境对气候变化的响应、海岸带海陆交互界面观测新技术新方法4个方面,综述了国内外研究进展与发展趋势,展望了海陆交互作用及其生态环境效应研究的未来发展方向。   相似文献   

16.
Coastal lagoons with small catchment basins are highly sensitive to natural processes and anthropogenic activities. To figure out the environmental changes of a coastal lagoon and its contribution to carbon burial, two sediment cores were collected in Xincun Lagoon, southeastern Hainan Island and (210) ~Pb activities, grain size parameters, total organic carbon(TOC), total nitrogen(TN), total inorganic carbon(TIC) and stable carbon isotopes(δ~(13)C) were measured. The results show that in 1770–1815, the decreasing water exchange capacity with outer open water, probably caused by the shifting and narrowing of the tidal inlet, not only diminished the currents and fined the sediments in the lagoon, but also reduced the organic matter of marine sources. From 1815 to 1950, the sedimentary environment of Xincun Lagoon was frequently influenced by storm events. These extreme events resulted in the high fluctuation of sediment grain size and sorting, as well as the great variation in contributions of terrestrial(higher plants, soils) and marine sources(phytoplankton, algae, seagrass). The extremely high content of TIC, compared to TOC before 1950 could be attributed to the large-scale coverage of coral reefs. However, with the boost of seawater aquaculture activities after 1970, the health growth of coral species was severely threatened, and corresponding production and inorganic carbon burial flux reduced. The apparent enhanced inorganic carbon burial rate after 1990 might result from the concomitant carbonate debris produced by seawater aquaculture. This result is important for local government long-term coastal management and environmental planning.  相似文献   

17.
日照市海水入侵现状与治理方案   总被引:1,自引:1,他引:0  
通过遥感解译对日照市海水入侵现状进行分析,对海水入侵程度进行评价,发现养殖池和河滩面积在大幅增加,盐田、滩涂、沙滩等均在减少。在日照沿海地区,地下水的储备与人类的用水需求之间存在矛盾,人类过量开采地下淡水是产生海水入侵的主导因素。建议采取兴建地下水库、减少地下水开采和人工回灌等措施防治海水入侵。  相似文献   

18.
INTRODUCTIONMarinehedsresultinginenomouslossestousuallyPOpulousandeconondcallyde-veloPedlowandcoastalandestUdrineregi0nsareforngseriousattenti0n.msarticlediscussesP0ssiblepreventivemeasaresagainstInariflehazaIdsbasedonacasestUdyoftheestUedesoftheChanaiiangffiverandQiantanffiver-ThesetwoareasoftheChanaiiangDeltaareboicalofc0astalregionsfreqUenilysufferingfromdrinehazanls,andarethemostsociallyandeconondcallydeveloPedregionsinChina.Theirinhabitantshaveahist0-ryofmorethanathouSandyeare0…  相似文献   

19.
China's eastern coastal area marine hazards (storm surge, erosion and deposition by tidal currents and seawater intrusion) and the history, present situation, experiences and problems of inhabitants in their fight against marine hazards are discussed in this paper, which also suggests counter-measures against, and scientific and rational management of, coastal area marine hazards in order to protect the coastal and estuarine ecosystems.  相似文献   

20.
PHOTOCHEMICAL OXIDATION OF BENZOTHIOPHENE IN SEAWATER   总被引:3,自引:0,他引:3  
INTRODUCTIONphotochemicaloxidationofbenzothiopheneinseawaterinordertolearnmoreabouttheremovalpatternofthispollutantinmarineenvironments.Benzothiophenewaschosenforthisstudysinceitisthesimplest  Thehigh -pressuremercurylampusedinthisstudycouldproducelig…  相似文献   

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