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1.
本文讨论了2006年12月冬季和2007年8月夏季海南省万泉河、文昌/文教河河流及河口溶解态铝的含量、分布及季节差异。结果发现,万泉河冬、夏两季河流及河口溶解态铝的平均含量分别为(156±127)和(157±97)nmol/L,季节差异不明显。文昌/文教河冬、夏两季河流及河口溶解态铝的平均含量分别为(242±156)和(222±66)nmol/L,冬季溶解态铝的平均含量略高于夏季。万泉河溶解态铝在河海混合初期表现为清除行为,而后表现为保守混合行为,而文昌/文教河则表现出明显的非保守混合行为,在中等盐度区域存在明显外源输入,原因可能是八门湾底沉积物再悬浮过程中释放的影响。部分河流上游采样点由于受到人为活动引起的污水排放的影响,溶解态铝含量明显增加。万泉河、文昌/文教河溶解态铝的平均含量明显低于我国其他及世界主要河流。  相似文献   

2.
利用多道α能谱仪,对2005年8~9月在海南岛近海采集的7个沉积岩芯进行了210Pb的沉积速率测定,探讨了海南岛近海陆架上现代沉积速率的区域性分布特征,结果表明:位于港湾内的B1168站位由于沉积物供应充足,有最高的沉积速率,达2.9 cm/a;位于河口海湾附近且受沿岸流影响的B289站位,有很高的沉积速率,可达1.6 cm/a,沉积环境较稳定;位于西南海底沙脊区北缘且靠近昌化江河口的B97、B135、B10站位也有较高沉积速率,分别达到1.0、0.89和0.47 cm/a,在表层都出现了210Pb放射性活度倒置的现象,表明所处区域有较强混合作用;处于西南外陆架的C4站位受北部湾环流影响,沉积速率为0.6 cm/a;位于东部外陆架的B377站位处于上升流区,沉积速率较低,为0.21 cm/a.可见,海南岛近海陆架上的现代沉积速率存在着明显的区域分布:在物质来源丰富的沿岸流作用区和河口区附近,现代沉积速率很高;在陆架环流沉积作用区,现代沉积速率也较高;在水深较大的外陆架上,由于沉积物供应相对匮乏,沉积速率一般较低;在近岸潮流沙脊区,由于水动力很强,无法形成现代细粒沉积.同时,在陆架上,沉积速率有随着水深的增加而降低的趋势.由此可见,海南岛近海海域的沉积速率与该区的物质供应、水动力条件和海底地形等因素有密切关系.  相似文献   

3.
海南岛东西陆架秋季悬浮体分布特征对比   总被引:3,自引:0,他引:3  
2005年8月到10月国家海洋局第二海洋研究所在海南岛周围进行了近海底质和悬浮体的调查。利用悬浮体调查数据对比了海南岛东西两侧陆架悬浮体浓度的分布特征,并探讨影响其分布的因素。研究结果表明,海南岛东西两侧陆架的悬浮体在垂向上的分布形式基本有3种:增加型、C型和稳定型。海南岛东西侧陆架在悬浮体浓度分布方面存在较大差异,自然条件是造成这种差异的主要因素。物质来源对悬浮体体积浓度分布也有较大影响。悬浮体体积浓度在局部的高值、高梯度区与流系(如暖涡和上升流)有较为密切的关系。在东侧陆架,盐度分布与悬浮体的浓度分布有一定的关系。  相似文献   

4.
海南小海表层沉积环境及重金属污染综合评价   总被引:3,自引:0,他引:3  
利用2008年在海南小海采集的30个表层沉积物样品,对其进行了TP、TN、TOC、石油类和Hg、Cd、Cu、Pb、Zn、Cr、As重金属元素含量的测定,并采用综合污染指数法和潜在生态危害指数法对该区重金属的污染程度进行了评价,结果显示:(1)研究区表层沉积物中TP含量呈中部高沿岸带低的特征,这可能是由于沿岸带初级生产力高于小海中部,所消耗的磷营养盐较多的缘故;TOC和TN的含量则表现为与TP含量分布相反的特征,即沿岸带高而中部低,这可能是由于沿岸带人为活动对小海沿岸碳、氮元素含量的影响较大的缘故。Hg、Cd、Cu、Pb、Zn、Cr和As 7种重金属元素均表现出在小海中部附近海域和北坡镇沿岸带出现高值,而在小海北边入口处和梅开-英豪沿岸带出现低值的分布特征,这可能与在北坡镇附近的工业区排水时向该海域输入了含有这些重金属元素的污染物所致,而其它区域则受工业排污影响较小,也可能与入海口的潮汐水动力的稀释作用有关。(2)研究区综合污染指数(ISQJ)、潜在生态危害污染指数(ERI)的最大值分别为2.283和240.0,平均值也较高,分别达1.494和151.0,各重金属元素的潜在生态危害系数(Eri)大小顺序为:Hg>Cd>Pb>As>Cu>Cr>Zn,反映出研究区将达到中等污染程度的现状,而某些海域的污染程度已达到重污染水平,研究区受Hg和Cd元素污染较为严重。由此可见,小海的沉积环境已受到较为严重的破坏,未来该海域应该重视重金属Hg和Cd元素的污染治理,以避免小海沉积环境的进一步恶化。  相似文献   

5.
为揭示中国东南沿海地区210Po和210Pb的大气沉降时空变化特征,探讨该地区气溶胶的停留时间,于2013年1月至2014年12月对厦门地区210Po和210Pb的大气沉降通量进行了时间序列研究。结果发现,210Po和210Pb的平均日沉降通量分别为(65.38±4.79) mBq/(m2·d)(n=54)和(0.78±0.09) Bq/(m2·d)(n=54),表现出明显的周年变化。东北季风期间,210Po和210Pb的沉降通量较高,而西南季风期间其通量较低。2013年和2014年,210Po的年沉降通量分别为19.29 Bq/(m2·a)和9.25 Bq/(m2·a),210Pb的年沉降通量分别为159.2 Bq/(m2·a)和189.6 Bq/(m2·a)。两核素的年沉降通量表现出不同程度的年际差异。210Po与210Pb沉降通量之间存在显著的线性正相关关系,揭示了大气中210Po和210Pb具有相同的迁出机制,降雨和大气中核素含量是影响210Po和210Pb沉降通量的主要因素。该研究结果可以为探求台湾海峡海水中210Po与210Pb的收支平衡提供大气来源项。  相似文献   

6.
Vertical profiles of dissolved and particulate 210Po and 210Pb were measured across the redox transition zone at Station F1 in Framvaren Fjord, Norway. In this fjord, a sharp decrease in pH above the O2/H2S interface facilitates the aerobic dissolution of MnO2. In contrast, Fe(II) concentrations begin to increase only at the O2/H2S interface depth. Activity profiles reveal that dissolved 210Po and 210Pb are sequestered efficiently by particulates in surface waters. As polonium-210 and lead-210 activities descend down into the aerobic manganese reduction (AMR) zone, they are remobilized during the reductive dissolution of the carrier phase oxyhydroxides. Both 210Po and 210Pb are highly enriched at the O2/H2S interface where an active community of microbes, such as anoxygenic phototrophs (e.g., Chromatium, Chlorobium sp.), thrives. The coincident peaks in 210Po, 210Pb and microbial biomass suggest a strong biological influence on the behavior of these radionuclides. There is a strong covariance between the vertical distribution of Mn and Pb, indicating that their redox cycling is closely coupled and is likely microbially mediated.  相似文献   

7.
利用2003年9月中国科学院海洋研究所"金星二号"调查船采自胶州湾海域的6个沉积岩心样品,对其(210)Pb放射活度和重金属Zn、Cr、Cu、Pb、Cd、Co和Ni元素的含量进行了测定,计算了其不同分布模式下的沉积速率和沉积通量,并分析了相应的岩层中重金属元素累积过程,探讨了其沉积环境意义,结果表明,胶州湾中部、东部沿...  相似文献   

8.
Mangrove wetlands can reduce heavy metal pollution by trapping heavy metals. In this study, the concentration,transport and bioaccumulation of Cr, Cd, Cu, Zn and Pb in the sediments and different parts of Aegiceras corniculatum at four different sites in the Qinzhou Bay in southwestern China were investigated. The results showed that although the potential ecological risk of all five heavy metals was slight, the concentration of Cr was at a moderate pollution level due to the emissions of industries and aquaculture waste water. Core sediment records indicated that the concentrations of heavy metals at the depth of 0–20 cm were relatively high, showing an increasing trend of heavy metals over the past 20–30 years. Cr, Cu, Pb and Cd accumulated mainly in the roots of A. corniculatum, while Zn accumulated mainly in the stems. Aegiceras corniculatum showed the strongest transport capacity for Zn and Cu and the strongest bioaccumulation ability for Cd. Compared with other mangrove communities, A. corniculatum can be chosen as a restoration species in tropical and subtropical coastal zones polluted by Zn, Cu and Cd.  相似文献   

9.
~(210) Po and ~(210) Pb are increasingly used to constrain particle dynamics in the open oceans, however they are less used in coastal waters. Here, distributions and partitions of ~(210) Po and ~(210) Pb were examined in the Taiwan Strait, as well as their application to quantify particle sinking. Activity concentrations of dissolved ~(210) Po and ~(210) Pb(0.6 μm)ranged from 1.21 to 7.63 dpm/(100 L) and from 1.07 to 6.33 dpm/(100 L), respectively. Activity concentrations of particulate ~(210) Po and ~(210) Pb varied from 1.96 to 36.74 dpm/(100 L) and from 3.11 to 38.06 dpm/(100 L). Overall,particulate ~(210) Po and ~(210) Pb accounted for the majority of the bulk ~(210) Po and ~(210) Pb. 210 Po either in dissolved or particulate phases showed similar spatial patterns to 210 Pb, indicating similar mechanisms for controlling the distributions of ~(210) Po and ~(210) Pb in the Taiwan Strait. The different fractionation coefficients indicated that particles in the Zhemin Coastal Current(ZCC) inclined to absorb 210 Po prior to 210 Pb while they showed an opposite effect in the Taiwan Warm Current(TWC). Based on the disequilibria between ~(210) Po and ~(210) Pb, the sinking fluxes of total particulate matter(TPM) were estimated to range from –0.22 to 3.84 g/(m2·d), showing an overall comparable spatial distribution to previous reported sediment accumulation rates. However, our sinking fluxes were lower than the sedimentation rates, indicating a sediment resuspension in winter and horizontal transport of particulate matter from the Taiwan Strait to the East China Sea.  相似文献   

10.
Eighteen short cores were analyzed for major and trace metals (Al, Fe, Ca, Mg, Mn, Si, K, Ti, Pb, Zn, Cu, Ni, Cr), 210Pb, 137Cs, and other sediment characteristics, so as to describe the chronology of pollution and calculate metal concentration factors and fluxes. Substantial evidence was found that trace metal profiles are influenced by anthropogenic sources and by changes in sediment composition. Only Zn presents concentrations (up to 13.1 μmol g) and concentration factors (1.3 to 13.2) that can be attributed to heavy contamination. Pb, Cu and Ni, in this order, are less significant. The areal distribution of concentrations and inventories reflects the importance of direct sources, in particular the industrial area of Porto Marghera and the Dese river. The inventories of excess metals, above pre-industrial levels, were determined for each core and the three different parts of the study area, the amounts of Zn accumulated in sediments are 11.0 Mmol, 5.1 Mmol and 0.37 Mmol in the Campalto, S. Erasmo, and Palude di Cona areas, respectively. Ruxes were also calculated and compared with those suggested for the atmospheric delivery by Cochran et al. [(1995)b. Atmospheric fluxes of heavy metal contaminants to the Venice Lagoon, Rapp. Comm. Int. Mer Médit., 34, 136.], the atmospheric contribution is predominant or significant in many cases, especially at sites far from the major local inputs. Concentrations and fluxes show a significant increase in the anthropogenic metal supply starting from the second decade of this century, with maximum inputs in the period between the (1930)s and the (1970)s. At some stations a decrease in heavy metal contamination of surficial sediments was found and this could be ascribed to a reduced input of pollutants in recent years.  相似文献   

11.
The 210Pb geochronology, heavy metal concentrations (Zn, Cu, and Pb), and stable Pb isotope ratios (206Pb/207Pb) of three sediment cores collected from Jakarta Bay were analyzed to decipher the history of heavy metal contamination in the period 1900–2006. The chemical and isotopic analyses clearly suggest that anthropogenic metal accumulation in the sediments began in the 1920s and increased greatly from the 1970s until the end of the 1990s. From the end of the 1990s to 2006, accumulation rates were constant or decreased for Zn and Pb near the coastal industrialized area. Comparison of economic data and sociological information suggests that the decline in the concentrations of heavy metals could be attributed to the stricter environmental regulations which were enforced at the end of 1990s. However, metal contamination is currently still an important cause of concern in dealing with environmental preservation and protection in Jakarta Bay.  相似文献   

12.
用原子吸收光谱法(AAS)和原子荧光光度法(AFS)测定了采集于北海银滩镇、厦门海门岛、宁德漳湾镇、乐清西门岛、温岭坞根镇、三门花桥镇等地区自然滩涂以及温岭坞根镇养殖区的可口革囊星虫(Phascolosoma esculentas)及其栖息地的底泥样品中Zn、Cu、Mn、Fe、Cd、Pb、Hg 和As 等8 种重金属含量, 并对检测结果进行了含量特征、生物体与栖息地底泥中重金属含量相关性分析、生物体重金属富集系数分析。结果表明: 不同栖息地可口革囊星虫间的重金属含量差异性显著(P<0.05), 各群体中Pb 含量均超过标准, 厦门海门岛群体中Cd 含量超标; 厦门海门岛、乐清西门岛自然滩涂栖息地和温岭坞根镇养殖区等底泥中重金属含量相对较高, 所有采样点底泥中Cu 含量以及乐清西门岛自然滩涂底泥中Cd 含量达到沉积物质量标准Ⅱ类; 可口革囊星虫对Zn、Cu、Fe 的富集系数均小于1, 对Mn、Cd、Pb、Hg 和As 的富集系数均大于1。Zn、Cu、Fe、Pb 和As 的富集系数在大部分群体间差异性较小; 可口革囊星虫中的Fe 和As 含量与底泥中的Fe 和As 含量高度正相关, Zn 和Hg 含量的相关性次之, 其余重金属元素含量的相关性较差。  相似文献   

13.
Spatial and temporal distributions of nutrients (N and P) and heavy metals (Cu, Zn, Pb and Cd) in the intertidal sediments at Dongtan wetland of the Changjiang River (Yangtze River) Estuary were examined by laying one transect running seaward to landward during January, April, June, August and October of 2005. Total nitrogen (TN) and heavy metal concentrations in the intertidal sediment showed an increasing trend from open bare °at to the high marsh, with the maximum concentrations in the high marsh and the minimum values in open bare °at. In contrast, sediment total phosphorus (TP) concentrations changed little among sampling sites. One-way ANOVA found that there were signiˉcantly temporal variations of nutrients and heavy metals concentrations in the intertidal sediment (P <0.05). The concentrations of heavy metals generally showed an increasing trend from January to October. As compared with other large estuaries, heavy metal contamination in the intertidal sediment of the Changjiang River Estuary was relatively low.  相似文献   

14.
沉积物对水体中的重金属具有源和汇的双重作用。河流沉积物中重金属含量与相态分析是研究流域重金属元素循环,评价其生态危害性的基本方法。采用1mol/L的盐酸对椒江悬浮物和河漫滩沉积物进行淋滤,研究重金属(Zn、Pb、Cr、Cu和Cd)在酸溶相和酸不溶相中的分布特征,分析并揭示其主要来源和生态效应。椒江沉积物中Zn、Pb、Cu、Cd的含量明显高于浙东地区土壤背景值,酸淋出率>60%,当环境条件发生变化时,酸溶相中的重金属易释放到水体中,具有较高的生态风险。相关性和主成分分析揭示,酸溶相中的重金属主要吸附、络合于有机质和铁锰氧化物中,其来源受工业、农业排放的控制。富集因子分析和潜在生态危害评价表明,椒江沉积物中Cd的富集程度最高,尤其在上游永安溪河段,Cd达到显著富集。而Zn、Pb、Cr、Cu均为轻度—中度富集。  相似文献   

15.
对海南省花场湾内表层沉积物中重金属的含量进行测定,探讨其分布特征、相关性及潜在生态危害程度.含量测定结果表明,花场湾表层沉积物中的Cu、Pb、Zn、Cr、Cd、Hg、As的含量范围分别为8.41~51.45、5.96~30.73、16.87~99.15、18.60~57.80、0.12~0.76、0.020~0.073、6.02~17.56 mg/kg,均值分别为28.19、18.35、50.48、35.75、0.32、0.05、12.71 mg/kg.相关性分析结果表明,Cu、Pb、Zn、Hg、Cr及Cd具有相同污染源,主要受养殖影响;此外,Cu、As、Hg受潮汐影响较大,Pb与Zn受渔船及潮汐影响较大,Cd与Cr受沿岸虾塘影响较大.重金属潜在生态危害评价结果表明,研究区以中等生态危害为主,其次为强生态危害与轻微生态危害,多种重金属潜在生态危害指数(RI)高值基本位于花场湾潟湖中心.单金属潜在危害系数程度较高的是Cd与Hg,潜在生态风险大小依次为:CdHgAsCuPbCrZn.  相似文献   

16.
通过对长岛北部海域101个站位表层沉积物进行取样,研究了表层沉积物类型和粒度分布,探讨了As、Pb、Hg、Cr、Cd、Cu、Zn和Ni等8种重金属元素的含量、分布特征及其相关性,并采用潜在生态风险指数法、沉积物环境质量评价和地累积指数法对该海域重金属情况进行了风险评价。结果表明:重金属元素主要在大钦岛南部、北隍城岛北部和小钦岛北部海域富集;大部分重金属元素与平均粒径呈显著正相关;沉积物类型受潮流及地形地貌等因素影响。风险评价结果表明:研究区整体处于很低的风险环境,潜在生态风险指数法显示仅部分站位中Cd和Hg处在中等生态风险;内梅罗综合污染指数法显示As仅在小钦岛西北部海域为尚清洁环境,Cr仅在各岛屿周边海域为尚清洁环境;地累积指数法显示Cd仅在大钦岛西南部和北隍城岛西部海域处于轻微污染环境。来源分析表明:Cd、Hg、Cu、Zn、Hg、Ni和Cr受养殖、排污等人类活动影响,As仅受到岛屿及近岸土母质影响。  相似文献   

17.
应用半静态双箱动力学模型室内模拟了沉积物暴露条件下文蛤Meretrix meretrix 对Cu、Pb的生物富集,通过对富集与排出过程中文蛤体内重金属污染物的动态监测和对富集与排出过程监测结果的非线性拟合,得到了文蛤富集重金属的吸收速率常数K1、排出速率常数K2、生物富集因子BCF(bioconcentration factors)、生物学半衰期B1/2等动力学参数。拟合结果得到的Cu、Pb各动力学参数分别为,K1为4.6333—72.3754;K2为0.0512—0.0798;BCF为60.7646—1414.9634;B1/2为8.69—13.55。对模型的拟合优度检验结果显示,沉积物暴露条件下文蛤对重金属Cu、Pb的生物富集数据符合双箱模型,模型的拟合优度良好。比较结果得出,吸收速率常数K1及生物富集因子BCF均随着外部水体金属暴露浓度的增大而减小;文蛤对Cu富集能力大于Pb;Cu在文蛤体内的生物学半衰期B1/2大于Pb;理论平衡状态下生物体内Cu、Pb的含量CAmax随着外部水体中金属暴露浓度的增大而增大,且呈显著正相关,实验结果表明沉积物暴露条件下双箱动力学模型在一定条件下是可以应用于文蛤的富集动力学研究的,仍需要进一步开展不同条件下实验研究分析。  相似文献   

18.
鼠尾藻对重金属锌、镉富集及排放作用的研究   总被引:5,自引:0,他引:5  
将鼠尾藻(Sargassum thunbergii)暴露在不同质量浓度锌和镉溶液里40 d,以及暴露20 d后,移入自然海水恢复20 d,分析了藻体内金属离子含量的变化。富集实验结果表明,鼠尾藻积累金属离子的量和暴露溶液金属质量浓度正相关、与暴露时间具有线性关系;暴露3 d,藻体的金属离子含量(除了暴露在Cd2+质量浓度为0.1 mg/L处理组)均显著增加;在Zn2+处理组,溶液里Zn2+质量浓度越大,线性关系越显著,而在Cd2+处理组,Cd2+质量浓度5.0 mg/L处理组藻体内Cd2+含量与暴露时间的线性关系则最低。排放试验结果表明,排放20 d后与排放0 d比较,藻体内的金属离子质量浓度均显著降低,但是均显著高于暴露前水平;在Zn2+溶液里,鼠尾藻暴露Zn2+质量浓度0.1 mg/L和Zn2+质量浓度5.0 mg/L 20 d后移入自然海水5 d后,藻体内的Zn2+含量与排放0 d相比显著降低,而在Cd2+溶液里,藻体排放5 d后,藻体内的Cd2+含量与排放0 d相比均显著降低。最终结果表明,鼠尾藻潜在地可作为一种指示生物,用于监测海洋环境重金属污染状况。同时,鼠尾藻对Zn2+和Cd2+具有较强的富集能力,可以利用鼠尾藻修复受重金属污染的海洋水体,尤其是锌的污染。  相似文献   

19.
长江口泥质区18#柱样的现代沉积速率及其环境 指示意义   总被引:1,自引:0,他引:1  
通过对长江口泥质区18#柱样进行137Cs和210Pb同位素测年分析,得到了柱样站点的现代沉积速率。结果表明,近50多年来沉积速率较大,且呈现阶段性差异:由137Cs时标计年法得到柱样1954—1964年的沉积速率为5.9 cm/yr,1964—2006年减小为 3.36 cm/yr;沉积柱样的210Pb剖面呈两段分布,由此得到沉积速率120~225 cm为5.47 cm/yr,对应于18~100 cm减小为4.58 cm/yr。对比分析两种方法得出沉积速率开始减小的时间为1968—1972年,并且采样点区域表层可能出现侵蚀现象,为研究长江口泥质区环境演变提供了依据。  相似文献   

20.
The diversity, community composition and 16 S rRNA gene abundance of bacterioplankton along a transect across an upwelling area off the eastern coast of Hainan Island(the Qiongdong upwelling) were investigated in August of 2016 using high throughput sequencing and quantitative PCR assay of 16 S rRNA genes. Compared with the offshore stations, the inner-shelf stations had higher bacterial gene abundance(up to 3 fold) and operational taxonomic unit richness, a result of the influence of upwelled a...  相似文献   

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