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1.
南沙群岛海域泻湖及礁外沉积物间隙水中的-2价硫 总被引：1，自引：1，他引：1
于1993年5月和1994年3－4月通过调查，用硫离子选择电极法研究南沙群岛海域泻湖及礁外沉积物间隙水中的∑S（－Ⅱ）及SO~(2-)_4，探讨泻湖内及礁外间隙水中-2价硫的分布特征，沉积物-海水界面间硫的扩散转移通量和-2价硫的热力学平衡控制体系。结果表明，该海区∑S（－Ⅱ）含量，泻湖间隙水中远比礁外高，人为活动剧烈的礁内泻湖高于人为活动少的泻湖，离礁近的礁外间隙水中的高于远离礁的间隙水中的。在礁外沉积物间隙水中-2价硫含量呈垂向增加的趋势，沉积物-海水界面间HS-，S2-均是从沉积物向上覆海水扩散，SO反之。礁内泻湖的扩散量远高于礁外的，HS-扩散总平均为61．34μmol／（m2·d），SO为-0．41mmol／（m2·d）；礁外泻湖的HS-总平均为14．96μmol／（m2·d），SO为-0．35mmol／（m2·d）。该海区的-2价硫主要由S＋2e→S2-氧化还原电对控制，平衡时Eh计算值与实测值接近，单质疏作为亚稳态可存在于沉积物中，并可与溶解铁继续形成自生黄铁矿（FeS2）沉淀。 相似文献
2.
江阴岛海域溶解态Cu,Pb,Cd的含量及其与营养盐的关系 总被引：2，自引：0，他引：2
首次报道了福建省福清市江阴岛海域溶解态Ｃｕ，Ｐｂ，Ｃｄ的含量，并探讨了它们与营养盐的关系。１９９０年５月溶解态Ｃｕ，Ｐｂ，Ｃｄ的平均含量分别为０．８２、０．３８０、０．０２２μｇ／ｄｍ＾２，１０月的平均含量分别为０．７６、０．３８２、０．０３２μｇ／ｄｍ＾２。其５月溶解态Ｃｕ与无机氮Ｎ，硅酸盐间的线性回归相关式分别为Ｃｕ、（μｇ／ｄｍ＾３）＝０．４３８＋０．０３７７Ｎ（μｇ／ｄｍ＾３）、Ｃｕ（μｇ 相似文献
3.
九龙江口生物可利用磷的行为与人海通量 总被引：1，自引：1，他引：0
于１９９５年３、５月在九江口进行两个航次的现场调查,研究不同形态磷的河口行为,并估算生物可利用磷的入海通量。结果表明,在Ｓ〈２０区域内,溶解活性磷（ＤＲＰ）的行为受控于“缓冲机制”,其含量在８－１０μｇ／ｄｍ＾３水平上下波动。颗粒磷中ＭｇＣｌ２可提取磷（ＭｇＣｌ２－Ｐ）含量随盐度增大而增大,并与叶绿素ａ以及悬浮物Ｆｅ、Ｍｎ、Ａｌ含量呈正相关关系。ＮａＯＨ／ＮａＣｌ可提取磷（ＮａＯＨ／ＮａＣｌ－Ｐ） 相似文献
4.
本研究利用高压液相色谱法（ＨＰＬＣ）法测定：外源睾酮（Ｔ）和甲基睾酮（ＭＴ）（１０μｇ／ｇ）腹腔注射给入真鲷（Ｐａｇｒｏｓｏｍｕｓｍａｊｏｒ）鱼体后，在血液中的代谢状况．证明，Ｔ和ＭＴ的吸收和清除很快。ＭＴ在注射１ｈ达最大吸收峰（２８３ｎｇ／ｍｌ），２４ｈ内很快降低。Ｔ的吸收和清除状况与ＭＴ相似，不同的是其吸收值（最大值为６４ｎｇ／ｍｌ）比ＭＴ低许多。随着鱼类养殖至商品规格，类固醇激素的含量将降至很低，因此，ＭＴ可做为一种生长促进因子用于水产养殖生产。 相似文献
5.
主要研究了南沙群岛海域 湖及其礁外沉积物间隙水中的Ｆｅ２＋，Ｍｎ２＋，Ｍｎ／Ｆｅ值及礁外／ 湖值、沉积物—海水界面扩散通量、沉积类型及其氧化还原环境。结果表明，间隙水中Ｆｅ２＋，Ｍｎ２＋浓度 写湖高于礁外，锰高于铁，礁外／渴湖值Ｆｅ２＋为０．２８，Ｍｎ２＋为０．６６，Ｍｎ／Ｆｅ值 湖内为１．４７，礁外为３．５２，界面扩散Ｆｅ２＋，Ｍｎ２＋均是从沉积物向上覆海水扩散，扩散量的Ｍｎ／Ｆｅ值 湖为１．３８，礁外为３．８４，Ｆｅ２＋，Ｍｎ２＋浓度及其扩散特征的不同是由其氧化还原速率、扩散速度、控制体系及其氧化还原环境共同作用的结果。 湖沉积物以粗粉砂为主，为还原特征；礁外沉积物以粉砂质粘土软泥为主，为弱还原特征，从间隙水中Ｆｅ２＋，Ｍｎ２＋浓度，Ｍｎ／Ｆｅ值及其礁外／ 湖值，Ｆｅ２＋，Ｍｎ２＋界面扩散及其Ｍｎ／Ｆｅ值，沉积物氧化还原度（ＲＯＤ）的研究得到一致的结论，南沙群岛海区湖沉积物的还原性比礁外沉积物强。 相似文献
6.
东海沉积物间隙水中的碳酸盐及铁、锰的控制体系 总被引：3，自引：0，他引：3
本文根据1987年所采样品研究了东海沉积物间隙水中的碳酸盐、铁和锰。结果表明:长江口外区沉积物中的方解石有一定程度的白云石化;冲绳海槽区及台湾海峡北沉积物中有比较强的CaCO_3溶解作用,CaCO_3溶解产生的Ca~(2+)占间隙水中总钙的20—53％;三个区域均有部分的方解石转化为磷灰石;在东海沉积物间隙水中铁由“Fe_2O_3-SO_4~(2-)-FeS_2”体系控制,高价铁被还原生成的Fe~(2+)和SO_4~(2-)还原产生的S~(2-)可形成黄铁矿(FeS_2)沉淀;而锰受MnCO_3溶解和沉淀控制,MnCO_3溶解产生的Mn~(2+)可占间隙水中总Mn~(2+)浓度的60—80％。锰受氧化还原作用影响小。 相似文献
7.
沉积物间隙水中的溶解有机碳(DOC)是沉积物有机质矿化过程中的中间产物[1],沉积物中的有机质通过微生物水解和(厌氧)发酵等方式溶解成各类具有不同分子量的有机化合物,通常总称为溶解有机碳,并释放到沉积物间隙水中.而溶解有机碳又进一步被细菌等微生物所利用,最终被氧化为溶解无机碳,完成有机质的矿化过程.因此,沉积物间隙水中DOC的浓度是消耗和生成之间平衡的结果[1].已有的研究表明,沉积物间隙水中DOC的含量显著高于底层水体中DOC的含量,导致其向底层水体的扩散;近期的研究也表明,来自海底沉积物的DOC通量是底层水体中DOC的重要来源,是海洋有机碳储库中的重要组成之一[2~4]. 相似文献
8.
实验研究了一个中型水库（黄同水库）中几种主要微量营养元素（Ｆｅ、Ｍｎ、Ｚｎ、Ｃｕ、Ｍｏ）的存在形态、分布及其季节变动。主要结果为：（１）水库中Ｆｅ、Ｍｎ、Ｚｎ和Ｃｕ的平均总浓度分别为３６４．３、１１２．１、９６．０１和３．２４μｇ／Ｌ;Ｍｏ的溶解态平均浓度为３．２６μｇ／Ｌ。Ｆｅ和Ｍｎ以颗粒态为其主要存在形式,而Ｚｎ和Ｃｕ则以溶解态为主。（２）该水库５种微量元素的水平分布呈均匀化特征,但其浓度具有较明显的季节性变化。其垂直分布互有差异,Ｆｅ、Ｍｎ、Ｚｎ随水层深度增加而递减,而Ｃｕ和Ｍｏ的垂直变化甚小。（３）微量元素存在形态与水化学因子存在一定相关性,ＰＦｅ、ＰＺｎ、ＰＣｕ与ＤＯ间具有良好负相关,而ＤＺｎ、ＤＣｕ、ＤＭｏ和ＰＺｎ、ＰＦｅ与叶绿素间均呈紧密正相关。 相似文献
9.
10.
以2011年6月和8月在长江口邻近海域采集的沉积物和间隙水样品为研究对象,讨论了沉积物中生物硅（BSi）和间隙水中溶解硅（DSi）的分布情况和影响因素,并初步探讨了生物硅的循环和保存。结果表明,表层沉积物中BSi的含量较低,且均小于1%。柱状沉积物中BSi的含量范围为0.34%~0.52%。C3、D1站位柱状沉积物中BSi的记录主要是由早期成岩过程控制,33#站位的分布特征主要是由水动力等变化控制。沉积物间隙水中DSi的浓度范围为101.6~263.9 μmol/L,低于纯BSi的溶解度;间隙水的pH值越大,沉积物的含水率越低,还原性越强,间隙水中DSi的含量越高。3站位生物硅的埋藏效率均较高,表明长江口邻近海域是潜在的硅的汇。沉积通量的分布与沉积速率和埋藏效率的分布一致,均有近岸高于远海的趋势。 相似文献
11.
The reversibility of the temperature effect on the chemical composition of interstitial waters of three deep-sea sediment samples was examined between 2 and 25°C for Cl, Na, K, Mg, Ca, Si, B, Mn and alkalinity. When the temperature of sediment samples was returned from 25°C to the initial value of 2°C, most chemical species gave nearly their initial concentrations. However, for alkalinity and in one case for magnesium, it took another three to four hours to reach their initial concentrations. 相似文献
12.
本文首次报道用沉积物捕捉器（ＳＴ）研究南沙群岛珊瑚礁湖沉降颗粒物中主要元素垂直通量、垂直转移形态、再循环过程及垂直通量与表层海水温度的关系。结果显示,作为生物化学沉积标志的Ｃａ、Ｍｇ具有最高的垂直通量,达１．４和０．１ｇ／（ｍ２·ｄ）以上,作为生物富集标志的Ｂｒ、Ⅰ也有较高的垂直转移量;垂直转移形态的研究表明Ｎａ、Ｋ、Ｃａ、Ｍｇ、Ｓｒ主要以碳酸盐结合态向海底转移,其中Ｃａ、Ｍｇ、Ｓｒ占９９％以上,Ｆｅ、Ｉ、Ｂａ主要以铁锰氧化物结合态向海底输送,在垂直沉降颗粒物到达海底后,有相当部分的主要元素可再循环进入水体中,Ｂｒ、Ｉ、Ｋ、Ａｌ的绝大部分进入再循环,Ｍｇ、Ｎａ、Ｃｌ有一半左右进入再循环,Ｃａ、Ｓｒ、Ｂａ、Ｆｅ大部分被埋葬;Ｎａ等９种元素的垂直转移量随ＳＳＴ呈指数降低响应,对ＳＳＴ的敏感性Ｆｅ＞Ｂｒ＞Ｓｒ＞Ｃａ＞Ｎａ＞Ｃｌ＞Ｍｇ＞Ｉ＞Ａｌ,这再一次验证了ＣａＣＯ３随温度升高,其溶解度降低、化学沉积量增加这一自然界的普遍规律,表明在珊瑚礁海水的垂直沉降颗粒物中主要元素是作为珊瑚的重要成分与ＣａＣＯ３一同被沉积下来的,ＣａＣＯ３起到稀释剂的作用。 相似文献
13.
黄河流域硅酸盐风化的讨论 总被引：3，自引：1，他引：2
根据2007年6月和7月采集的黄河干流及部分支流水样和河床砂样品数据,对黄河流域硅酸盐化学风化进行了探讨。在充分评估黄河流域的K+,Na+来源的基础上,确定了硅酸盐风化的K+量,并通过选定的硅酸盐风化(K/Na)比值,得到了硅酸盐风化的Na+量;通过测定流域内不同岩石类型分布的河床砂样品,得到河床砂样品硅酸盐部分(Ca/Na)和(Mg/K)的比值,确定了钙镁硅酸盐风化的Ca2+,Mg2+量;并据此估算了流域硅酸盐化学风化的CO2消耗率。如果选用黄河入海多年径流量58.02×109km3/a进行计算,则得到全流域硅酸盐风化CO2消耗率约为26.22×103mol/km2/a。若选用2007年的平均径流量24.83×109km3/a进行计算,则黄河流域硅酸盐风化引起的CO2消耗率约为11.19×103mol/km2/a。 相似文献
14.
顺序提取法探讨沉积物中主量元素在不同相态的分配特征 总被引：2，自引：0，他引：2
在Tessier以及欧共体标准局BCR等前人顺序提取方法的基础上，采用一套改进的顺序提取法对海洋沉积物以及一些水系沉积物标准物质的主量元素进行逐步提取。利用ICP—AES、ICP—MS方法分析了各提取液中Ti、A1、Na、Mg、K、Ca、P、Fe、Mn的含量以及它们在不同相态的分配特征，同时，进一步探讨了酸去除沉积物中非陆源组分的效果，结果显示，最后经盐酸淋滤后的样品，沉积物中的生物、自生组分已经被溶解，而残留下来的剩余物质基本上可代表海洋沉积物的陆源碎屑组分。 相似文献
15.
东海陆架晚第四纪沉积物化学成分及物源示踪 总被引：11，自引：0，他引：11
东海陆架EA1孔和EA5孔沉积物化学成分变化范围较大。与东海陆架表层沉积物相比，钻孔沉积物的Si,Al,Mg,Mn,Ti,P,Ba,Zr,Co,Ni,Cu,Zn,Cr明显偏高，而Fe,Na,Ca,Sr,Li,U明显偏低，与全球大陆地壳化学组成相比，钻孔沉积物的Si,Li,Rb,Ba,Th,Zr,Hf,Cu,Zn,Pb偏高，而Al,Na,Ca,Mg,Fe,Mn,Ti,P,Sr,U,Co,Ni,V,Cr偏低，钻孔沉积物的化学成分在垂向上具有明显变化，主要受岩性和沉积环境的控制，钻孔沉积物中元素的富集因子（EF）均小于10，接近于1，表明钻孔沉积物主要来自大陆地壳，一些元素因分异或外来物质加入而富集，一些元素则因分异带出而亏损，钻孔沉积物源区的DF值判别表明，钻孔沉积物与现代黄河，长江沉积物均有亲缘关系，可能是在末次冰期最盛期，由于气候带南移，干旱区域扩大，在古长江搬运沉积物中类似现今黄河沉积物的干旱组分明显增加，从而导致了地球化学示踪结果的长江与黄河双重性，或者说古气候的变化导致了古长江搬运物质成分的变化。 相似文献
16.
文采用有关离子缔合理论并结合具体海域的平衡矿物反应来计算海水中主要成分诸如Ca~(2+),Mg~(2+),K~+,Na~+,SO_4~(2-);Cl~-,HCO_3~-,F~-,CO_3~(2-),OH~-,离子的平衡分布,并应用于渤海的实际计算中。结果显示海水中主要阳离子基本上呈非缔合状态,而阴离子趋于与各种阳离子缔合,其中C1~-,F~-,Br~- 等卤族元素的趋势较弱。 相似文献
17.
顺序扫描ICP—AES法测定海洋沉积物中九种主要成分 总被引：2，自引：0，他引：2
用ICP—AES法测定海洋沉积物中铝、铁、钙、镁、钠、钾、钦、锰、磷等九种主要成分,方法简便,省时省力,测量精密度小于4％,可以满足海洋地球化学的要求。 相似文献
18.
The rapidly expanding industry of marine cage fish farming of sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) in the Mediterranean Sea over the last decade has often had damaging effects on the benthic aquatic environment near the fish farm installations. It has been observed that the food-remains, together with the pellets and metabolic products from fish, frequently form a “nepheloid” sediment layer covering large areas of the seabed. Under these conditions anoxia and/or hypoxia develop and affect benthic communities while the quality of the marine environment deteriorates for long periods, extending even beyond the life span of the fish farm itself. In most cases the affected areas act initially as sediment traps and in a second phase as secondary sources of organic carbon, nutrients and other substances.The aim of this paper is to explore the behaviour of such an affected area under different redox regimes by measuring the fluxes of ammonium, nitrite, nitrate, TDN, phosphate, TDP and silicate between the surface sediment and the overlying waters. To achieve this goal we constructed a prototype benthic chamber capable of sampling considerable quantities of affected undisturbed sediment along with its overlying water. The chamber was transported to the laboratory where simulation experiments reproducing the conditions occurring in nature, including the extreme ones, were carried out and studied carefully. The chamber allows the full and fine control of the dissolved oxygen concentration – and thus of the redox potential – as well as water temperature while subsamples of both water and sediment could be obtained and analysed for a series of chemical substances. The controlled laboratory chamber experiments reproduced four successional phases: 1) deoxygenation, 2) hypoxia, 3) reoxygenation and 4) anoxia.The results showed that even minor changes in the redox conditions at a relatively narrow zone near the water sediment interface have significant impacts on the concentrations of dissolved nitrogen, phosphorus and silicate compounds.With decreasing oxygen supply (phases 1, 2 and 4), the concentrations of ammonium, nitrite, TDN, phosphate, TDP and silicate rapidly increase, those of nitrate decrease. DON and DOP exhibit remarkable fluctuations.During reoxygenation (phase 3) the concentrations of ammonium stabilise, the nitrate concentration decreases while nitrite shows an increasing trend. Decreases in phosphate and silicate concentrations were also observed paralleled by TDP stabilization and DOP increasing trend. TDN shows a relatively small increase while the DON concentration fluctuates significantly. 相似文献
19.
根据１９８５－１９８７年来１９８９－１９９１年对青海湖及其水系的考查资料，研究其化学变化。结果表明，近３０年来，青海湖及其入湖河流水系在萎缩过程中，水系总矿化度增加，逐渐咸化。除尕海水的Ｍｇ＾２＋；耳海水的Ｋ＾＋，ＳＯ＾２－４，ＣＯ３＾２－；人湖河流水的ＳＯ４＾２－离子浓度减小外，青海湖、尕海及耳海本中Ｎａ＾＋，Ｃｌ＾－，ＳＯ４＾２－离子增加速率较大，Ｃａ＾２＋，Ｍｇ＾２＋等离子增加速率较小。尕海 相似文献
20.
Ferromanganese concretions within the Polish Exclusive Economic Zone (EEZ) are found mainly in the depth range 60–70 m on the thresholds between the Bomholm Basin and Slupsk Furrow and between the Gotland and Gdansk Basins. They also occur on elevations of the seafloor within the Bomholm Basin, on the southern slopes of Slupsk Furrow, and on the lower southwestern slopes of the Gotland Basin. They occur mainly as surface deposits on very thin (<0.2 m), poorly sorted lag deposits. The concretions are predominantly discoidal and are formed around a single nucleus of sandstone or erratic rock of variable size. The ferromanganese oxides display internal layering with alternate layers of almost black manganese oxides and buff iron axyhydroxides. The concretions consist mainly of todorokite and quartz, with lesser amounts of feldspar, kaolinite, and montmorillonite. They are characterized by relatively high Fe/Mn ratios (0.9–3.5) and high contents of detrital elements (Ti, Na, K, Ca, and Mg) but low contents of the transition elements (Cu, Zn, Pb, Cr, Co, and Ni). The deposits are associated with the very dynamic environment near the halocline, where internal waves erode the sediment and create conditions of sediment nondeposition favorable for the formation of the concretions. A number of factors contribute to the high abundance of ferromanganese concretions in the Baltic Sea. One is the high input of iron and manganese by the rivers draining into it This is a consequence of the widespread occurrence of bogs and swamps in the catchment area of the Baltic Sea, which results in the river waters having high humic acid contents and low pH. Another major factor is the buildup of dissolved iron and manganese in the anoxic basins of the Baltic Sea during periods of stagnation. These waters are flushed during major inflow events, when oxygenated water from the North Sea displaces the stagnant waters of the anoxic basins. Iron and manganese in these waters are then transported laterally and deposited in the surface of ferromanganese concretions on topographic highs. We believe that the iron is deposited rapidly after such events but that the manganese is deposited over a much longer time period, thus accounting for the layering in the concretions. The rate of deposition of these elements is essentially controlled by the input of oxygen in the waters of the North Sea. These periods of major inflows are grouped but significant events, for concretions occur on average about 11 times per century. We therefore estimate that the concretions have grown much more slowly than previously thought (about 0.013–0.018 mm/yr), and that a concretion 20 mm in diameter would have an age of about 500–800 years. Higher concentrations of heavy metals have been recorded in the outer layers of the concretions, and it is possible that these can serve as indicators of heavy‐metal pollution in the Baltic Sea. The concretions range from sporadic to intermediate abundance. As such, they have no economic potential. 相似文献