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1.
淮河中游重化工聚集区干流水体中多环芳烃研究   总被引:2,自引:0,他引:2  
淮河是中国七大河流之一,在中国国民经济发展中具有举足轻重的地位.有机物污染是淮河的主要污染形式.多环芳烃(PAHs)是一种典型持久性有机污染物(POPs),在水中的浓度较低.易于被悬浮物和沉积物吸附.为探讨淮河中游重化工聚集区干流水体中多环芳烃的含量和分布情况,2007年10月在淮南和蚌埠段采集悬浮物样品和表层沉积物样品.所采集的环境样品经自然风干后,利用二氯甲烷提取,无水硫酸钠和固相萃取柱组合净化,采用气相色谱-质谱联用法(GC-MS)同时定性和定量检测其PAHs含量,获得了美国EPA优先表中所列的16种PAHs含量数据,在此基础上探讨了淮河中游重化工聚集区干流水体悬浮物和沉积物样品中PAHs的分布特征.并初步分析了蚌埠市饮水源区蚌埠闸处PAHs的超标情况.结果表明:①淮河中游重化工聚集区干流水体环境样品中PAHs总含量变化幅度较大,其悬浮物浓度范围为1 169.44~4 048.86 ng/g,表层沉积物中浓度范围为91.98~1 292.52 ng/g;②就单一组分而言,悬浮物中萘含量最高,表层沉积物中二苯并[a,h]蒽最高;③受采样点环境和PAHs本身性质影响,悬浮物中PAHs量远大于其沉积物中量,整体呈现悬浮物中以低环PAHs为主、沉积物中以高环PAHs为主的特征;④根据<国家海洋沉积物质量标准>,蚌埠闸沉积物中PAHs超标严重,对蚌埠市的饮水安全产生一定的威胁,同时,此处悬浮物中PAHs含量也很高,潜在危害性更大,应给予重视.  相似文献   

2.
选用GC-MS分析官厅水库水体中16种多环芳烃(PAHs)的残留情况,并探讨该区域水体PAHs残留特征及其可能的健康风险.研究结果表明,12种PAHs均有不同程度的检出,PAHs总质量浓度为66.20~368.35ng·L-1,与国内其他地区相比,残留水平较低.利用健康风险评价模型对水体中PAHs所致健康风险的评价结果表明,水体中的PAHs的非致癌风险在5.84×10-13~4.90×10-12a-1之间,致癌风险低于2.89×10-9a-1,均低于国际辐射防护委员会推荐水平,目前研究区水体中PAHs类污染物对人体产生的健康风险处于较低水平.  相似文献   

3.
太湖饮用水源地多环芳烃分布特征和溯源分析   总被引:1,自引:0,他引:1  
持久性有机污染物引起的水质安全性问题日益受到广泛关注.为探究太湖饮用水源地多环芳烃的污染情况,对太湖饮用水源地表层沉积物进行了采样,对多环芳烃进行了定量检测,分析了研究区沉积物中多环芳烃浓度分布,同时采用2种方法(特征化合物法和主成分分析法)进行溯源分析.结果表明:太湖饮用水源地表层沉积物检测出11种PAHS,总量介于nd~280ng·g-1之间,平均值为114ng·g-1.和国内外其他湖泊、河口及海湾地区相比,太湖饮用水源地PAHs污染处于低水平.太湖饮用水源地表层沉积物PAHs组成以4环及5~6环PAHs为主(分别为43.86%和50.88%),2~3环PAHs相对较低(5.26%).太湖饮用水源地表层沉积物PAHs主要来源为化石燃料(包括汽油、柴油、煤、木柴等)的燃烧,但也与石油污染有关.本文成果可为太湖流域水污染防治和水资源管理提供科学参考.  相似文献   

4.
2016年12月北江清远段采集19个水和表层沉积物样品,采用气相色谱质谱(GCMS)法测定了样品中的多环芳烃(PAHs),分析了枯水期北江水环境中PAHs的污染水平,并对生态风险进行了评价。结果表明,枯水期北江清远段水中PAHs浓度范围为41. 2~413. 8 ng·L~(-1),主要以二环芳烃和三环芳烃为主,与国内外已报道河流湖泊相比,北江清远段水中PAHs污染处于中等污染水平;沉积物中PAHs浓度范围为54. 8~951. 5ng·g~(-1),以三环芳烃和四环芳烃为主,与国内外河流湖泊沉积物相比较,处于低污染水平。运用特征比值法对PAHs来源进行分析,北江清远段水和沉积物中枯水期PAHs污染来源主要由燃烧源所致,部分采样点存在混合源。通过计算终生致癌风险(ILCR)模型对北江清远段水体进行健康风险评价,结果表明,枯水期各采样点的致癌风险可忽略,婴幼儿的PAHs致癌风险高于青少年和成人。采用效应区间低、中值法(ERL/ERM)对枯水期表层沉积物中PAHs进行生态风险评价,个别点位表层沉积物中Dib超出ERL值,对生态环境潜在负面效应较小。  相似文献   

5.
为查明城市老工业搬迁区景观河道中多环芳烃(polycyclic aromatic hydrocarbons,PAHs)的分布特征并评估其生态风险,于2011年10月至2012年9月期间,以沈阳市卫工河为研究对象,调查了河水和底泥中16种国家环保部优先控制的PAHs环境滞留情况.通过季节性采样和沿河采样,初步查明了PAHs的时空分布特征,用熵值法初步评价了PAHs滞留的生态风险.结果表明:卫工河水中PAHs的平均质量浓度为0.721μg·L-1,底泥中PAHs平均质量分数为3 777.8 ng·g-1.河水与底泥中PAHs含量与溶解态有机碳含量均呈正相关关系.熵值法分析结果表明,卫工河PAHs滞留存在中度偏低水平的生态风险,但在某些样点区,底泥中萘和蒽的生态风险值较高.  相似文献   

6.
辽河支流条子河表层水体中多环芳烃的污染特征   总被引:1,自引:0,他引:1  
为了解辽河源头区典型支流——条子河四平段表层水体中多环芳烃(PAHs)的污染特征,分别于丰水期、平水期和枯水期采集条子河10个代表性断面的上覆水水样,测定了样品中16种优控PAHs的质量浓度、分析了其时空分布和来源,并对其生态风险进行了评价。结果表明:条子河表层水体中总PAHs的质量浓度(∑PAHs)范围为319.8~3 715.9 ng/L,平均值为1 476.0 ng/L,PAHs的组成以2~3环为主,占∑PAHs总量的53.1%~81.0%,5~6环的PAHs均未检测出。不同水期间,∑PAHs均值的大小顺序为:枯水期(2 035.0 ng/L)平水期(1 272.5 ng/L)丰水期(967.9 ng/L)。空间分布上,∑PAHs的检测最高值(3 715.9 ng/L)和平均浓度最大值(3 194.8 ng/L)均出现在位于四平市城区出境断面(汇合口)处。PAHs主要来源是石油、草木、煤炭的混合燃烧。条子河表层水体中苯并[a]芘的当量为5.1~36.1 ng/L,高于国家地表水环境质量标准值,条子河表层水体中PAHs存在一定的生态风险。  相似文献   

7.
西安冬季可吸入颗粒物中多环芳烃的组成及风险评价   总被引:3,自引:0,他引:3  
对2006-12-19~至2007-01-15采集的西安冬季昼夜大气可吸入颗粒物(PM_(10))样品,利用气相色谱-质谱联用仪(GS-MS)分析检测出美国EPA优先控制的12种多环芳烃(PAHs),结果显示,西安冬季大气PM_(10)中白天与夜晚总的PAHS平均质量浓度分别为312.0 ng·m~(-3)和346.0 ng·m~(-3),且PM_(10)中主要以4~5环的多环芳烃为主.采用苯并(a)芘(BaP)等效质量浓度(BaPE)评价PAHS的污染状况,结果表明,苯并(a)芘(BaP)白天及晚上的平均质量浓度分别为30.0 ng·m~(-3)和34.8 ng/m~3,计算得出西安冬季白天与晚上的BaPE平均值分别为45.3 ng·m~(-3)、51.0 ng·m~(-3),含量超过国家标准4.5倍以上.  相似文献   

8.
利用气相色谱-质谱联用仪(gas chromatography-mass spectrometer, GC-MS)分析了新安江河流-水库体系表层沉积物样品中16种优控多环芳烃(polycyclic aromatic hydrocarbons, PAHs)的含量.结果表明, 16种PAHs在表层沉积物样品中均有不同程度的检出,总浓度(∑_(16)PAHs)范围是260~1 652 ng/g dw (dry weight,干重),平均值为973 ng/g dw,以高分子量的PAHs为主.的区域是兰江∑_(16)PAHs值最高(1 530 ng/g dw),最低值出现在水库中心库区(600 ng/g dw). PAHs源解析表明,底泥中PAHs可能主要来源于煤和木材的燃烧.参考已有研究的分类标准,发现新安江上游、水库中心库区和富春江表层沉积物中PAHs处于中等污染水平,而水库回流区和兰江沉积物受到PAHs的污染较大.通过生态风险分析,发现所有底泥样品均可能存在急性毒理效应,但不存在频发性急性毒理效应.  相似文献   

9.
采集了浊漳河南源与当地南沟排水渠交汇处前后不同位置的水样并分析了其中的多环芳烃。结果表明,水中PAHs总量为119.32ng/L~144.77ng/L,排水渠断面的浓度高于其他断面,水体中苯并(a)芘均值浓度超出地表水的国家标准。水中PAHs以3环、4环为主;比值分析和主成分分析的结果显示,生产煤焦油以及使用煤焦油为原料的化工企业是水体中的PAHs的主要污染来源,移动源和燃煤源亦有一定贡献。  相似文献   

10.
对丰水期、枯水期黄河入海口8个站位表层沉积物中多环芳烃(PAHs)进行提取分离,利用气相色谱-质谱联用仪(GCMS-QP2010)定量分析。丰水期沉积物中共检出15种2-5环PAHs,而枯水期沉积物中共检出25种2-6环PAHs。丰水期表层沉积物中PAHs的总浓度在90.13~351.36ng/g之间,枯水期表层沉积物中PAHs的总浓度在39.34~218.92ng/g之间。同国内外其它河口、海湾相比,黄河入海口沉积物中PAHs相对较低,PAHs含量、分布具有明显的季节性变化特征,丰水期PAHs浓度高于枯水期PAHs浓度。由多环芳烃参数菲/蒽、荧蒽/芘与甲基菲/菲比值表征黄河入海口表层沉积物中PAHs主要来源于燃料不完全燃烧。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

19.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

20.
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