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1.
The amount of hydrogen ion exchange on the surface of amorphous silica in seawater was measured as a function of pH at 2 and 25°C. Hydrogen ion exchange with the cations present in seawater is pH dependent and at 25°C the fraction of the surface in the cation form increases from 9% at pH 7 to 22% at pH 8. The exchange is temperature dependent and at 2°C and pH 8, 14% of the exchange sites are occupied by cations, as opposed to 22% of the exchange sites at 25°C. These results were used to calculate the buffer capacity of a model sediment consisting of pore water and amorphous silica. For a sediment of 70% porosity, pH 7.7, and 25°C, the buffer capacity of sediment plus pore water is 67 times the buffer capacity of pure seawater. 相似文献
2.
Determinations of copper consumption capacity (CuCs.C) and labile copper concentrations in surface coastal seawater, using a copper ion selective electrode (Cu-ISE) potentiometric method under predominantly diffusive conditions, are reported. For evaluation of the copper concentrations, the points of the endpoint contiguity zone of the CuCs.C titration curve were treated by an ISE multiple standard addition technique. The results were compared with those obtained by means of a Chelex-100 (calcic form) ‘batch’ procedure-potentiometric stripping analysis.The labile copper of the sample was determined at concentrations down to 10.70 nM with an average RSD of 12%, independent of the Cu-ISE employed. For adjacent subsamples, the mean CuCs.C values obtained for El Way seawater were equivalent to 81.05 and 48.00 nM copper, with an RSD of 4 and 7%, and for Isla Santa Maria seawater the value was equivalent to 70.27 nM copper, with an RSD of 7%. The theoretical approach of the electrode diffusive mechanism proposed, which would depend, fundamentally, on the adsorptive, complexing and reducing properties of the dissolved organic matter in the seawater sample, allows simultaneous analytical determination of CuCs.C and labile copper concentration in seawater. 相似文献
3.
在现场水文地质调查的基础上,分别采集大沽河下游地下淡水、海水和含水介质样品,并测定它们的性质和组成,然后用渗流装置模拟海水驱替淡水的过程,测定驱替过程中含水介质渗透性(渗透系数、孔隙度、弥散系数等)和主要离子(Na 、K 、Ca2 、Mg2 )的变化规律,最后,采用数值模拟方法定量研究驱替过程中的水文地球化学作用。研究结果表明,驱替过程中发生了多组分的离子交换作用,Ca2 和Mg2 最大值高于海水和淡水中的离子浓度值,Na —Ca2 、Na —Mg2 发生离子交换;Mg2 达到最大值后有一个降低的"台阶"阶段,此时Mg2 —Ca2 发生离子交换;K 在驱替过程中主要表现为化学吸附。离子交换过程中伴随着矿物溶解-沉淀,海水比例40%后,方解石处于过饱和状态;在驱替过程开始阶段,石膏饱和指数逐渐升高,达到峰值后又开始下降,最后饱和指数又有所升高,但始终处于非饱和状态。 相似文献
4.
A number of dictating resins have been synthesized for extracting uranium from scawatcr. The feasibilities of extracting uranium directly from seawater by synthesizing chelating resins have been investigated by studying three factors:(1) the chelating ability of the resins for uranyl ion;(2) the competitive complex of calcium, magnesium and other cations with uranyl ion;(3) the competitive complex of carbonate ion with uranyl ion.It is suggested that the competitive complex of carbonate ion with uranyl ion should be the most important factor. 相似文献
5.
氯离子和硫酸根离子是海水中重要的无机阴离子，在研究海洋生态变化、海洋循环作用过程与海洋全球气候变化等领域具有重要的指示意义。其测定方法较多，但缺少相应的测试方法。本文对测定海水中Cl-，SO42-的离子色谱方法进行了优化，选用IonPacAS14碳酸盐选择性离子色谱柱，以3.5 mmol/L Na2CO3+1 mmol/L NaHCO3为流动相，可消除海水样品中碳酸盐及其他阴离子的干扰。该方法对Cl-检出限为0.29 mg/L，线性相关系数r2=0.999 2，对SO42-检出限为0.42 mg/L，线性相关系数r2=0.997 9。样品的加标回收率在95%~102%，Cl-和SO42-的相对标准偏差分别为1.92%和4.18%。该方法简便、迅速、灵敏、准确度高，可满足批量海水样品中Cl-与SO42-的准确测试。 相似文献
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7.
This paper first presents a new potassium reagent and efficient enrichment agent for direct recovery of potassium from seawater,i.e.,1,2,4,5-tetrahydroxybenzen -O,O'',O",O''"-tetraacetic acid (TTAH4).The synthetic method of TTAH4,its enrichment behaviour for potassium ion in low concentration solution and seawater,and the chemical structure of its corresponding potassium salt have been investigated.A mechanism which caused the uptake of potassium ion is suggested.Elementary analysis and IR-spectrum determination of the potassium salt proved correct evidence for a polynuclear complex,i.e., (TTAH3K)n.Thus,the mechanism which caused the uptake of potassium ion may be interpreted in terms of the formation of polynuclear chains as a continual sandwich type coordination complex. 相似文献
8.
The addition of stock copper and zinc nitrate solutions to filtered seawater (pH 7·91) resulted in a large pH shift which was more pronounced with copper. The pH shift was minimized by increasing the buffering capacity of seawater using 10 mm Tris-Tes pH 7·91. Subsequent experimentation was carried out in both unbuffered and buffered seawater.In unbuffered seawater, both copper and zinc had a pronounced inhibitory effect on Mytilus edulis sperm respiration with 50% inhibition occurring at 0.65 mm (41·3 ppm) copper and 1.0 mm (65·4 ppm) zinc. Egg respiration was also inhibited by copper with 50% inhibition occurring at 0.9 mm (57·2 ppm) whereas zinc inhibited egg respiration by only 30% at 1·5 mM (98·1 ppm).In buffered seawater, both copper and zinc produced an inhibitory effect on sperm respiration. However, with copper the inhibition was much reduced whereas zinc had tthe same inhibitory effect as in unbuffered seawater. In contrast to unbuffered seawater, egg respiration was stimulated by copper but zinc produced a comparable respiratory inhibition. The uptake of both copper and zinc in sperm and egg in buffered seawater increased with increasing metal concentration. Metal ion uptake, when expressed as ng ions μl cell volume?1, was approximately 3-fold greater in the sperm than in the eggs and in both cases zinc uptake exceeded copper uptake.At a seawater pH of < 7·5, in the absence of copper or zinc, the respiration of both egg and sperm was inhibited. The maximum levels of inhibition at pH 5·4 were 15% and 30% for sperm and egg, respectively.The differing actions of copper on egg respiration in buffered and unbuffered seawater appear to be due to enhanced copper uptake in unbuffered seawater. 相似文献
9.
大连大魏家滨海岩溶区海水入侵化学过程 总被引：10，自引：1，他引：9
通过不同比例的海水与淡水的混合作用及其混合水对碳酸盐岩的混合溶蚀作用的室内模拟实验,对滨海岩溶区海水入侵过程中的化学过程和水-岩作用进行了研究。在海水入侵过程中,海水与淡水的混合作用是以机械混合为基础的复杂化学过程;过渡带混合水对围岩(碳酸盐岩)的混合溶蚀作用则是以分子扩散和表面反应为主的复杂化学过程;而混合水与岩溶空间内的松散沉积物间的各种离子交换作用主要是阳离子交换吸附。室内模拟试验和野外实测地下水化学组分剖面资料对应说明,淡水、海水界面之间的过渡带中部区的混合溶蚀作用最强,亦可能是岩溶最发育的部位。 相似文献
10.
A novel approach to in situ extraction of Cs radionuclides from seawater is described which offers many advantages over previous methods. Cesium (stable and radioactive) is partially stripped from seawater as it passes in series through a tandem cartridge consisting of twin beds of ion exchange resin impregnated with cupric ferrocyanide. It is demonstrated that, when seawater passes through this cartridge at a constant flow-rate, collection efficiencies of each bed are the same, allowing the calculation of the seawater Cs nuclide concentration. The cartridge is made of inexpensive, readily available, PVC pipe fittings and is easily deployed under various field conditions. Procedures are described for resin preparation and desorption and radiochemical purification of the collected Cs. Thousands of liters of seawater can be stripped of Cs in this way, permitting substantial improvement in the sensitivity of measurement of 134Cs and 137Cs. 相似文献
11.
海洋真菌广泛参与近海生态系统的物质循环和能量流动, 同时与海洋动物之间存在复杂的相互作用。贝类是我国主要的海水养殖生物, 为深入了解海洋真菌与贝类养殖的潜在关系, 选择厚壳贻贝养殖区海水及8种组织真菌为研究对象, 利用荧光定量PCR以及ITS rDNA高通量测序解析养殖厚壳贻贝各组织及所处海水环境的真菌群落丰度和结构特征。结果显示厚壳贻贝养殖区内和边缘海域的真菌丰度显著高于养殖区外围海域; 从贻贝养殖区和组织中共获得1 409个OTUs, 其中粪壳菌纲(Sordariomycetes) 在海水真菌群落为优势纲; 而在贻贝组织中, 锤舌菌纲(Leotiomycetes, 足20.13%、肾脏14.72%)、座囊菌纲(Dothideomycetes, 鳃2.89%、后闭壳肌1.92%、血淋巴1.36%)、散囊菌纲(Eurotiomycetes, 性腺3.59%、足1.57%)和伞菌纲(Agaricomycetes, 性腺3.09%、消化腺2.71%、鳃2.50%)占据优势地位。多样性分析显示厚壳贻贝和海水间真菌群落存在显著性差异; Bray-Curtis相似距离分析显示贻贝真菌群落与养殖区内海水更为相似, 而与边缘和外围海水差距较大。厚壳贻贝不同组织间、不同区域海水间的Beta多样性差异主要来自物种替换; 贻贝与海水间真菌Beta多样性的差异主要来自丰富度差异。综上所述, 厚壳贻贝体内真菌具有组织差异性, 并且养殖活动改变了养殖区海水的真菌群落。研究结果将为贝类真菌资源、贝类-真菌相互作用及生态影响提供基础。 相似文献
12.
作者采用水化学演化图（hydrochemical facies evolution diagram,HFE-D）和海水入侵地下水质量指数（GQISWI）对山东威海文登区地下水的化学演化和海水入侵情况进行了分析。Piper图的结果表明文登区从北到南地下水的化学组成分别是Ca-HCO3、Ca-Mg-Cl、Na-Cl。HFE-D表明沿海地区的含水层中海水占主导地位,并且地下淡水补给不足,无明显淡化趋势;内陆地区含水层中的淡水多数处于海水侵入期,有咸化趋势。运用GQISWI、地理信息系统和空间插值法结合,得到了文登区浅层海水入侵现状图。另外,作者考虑渗透系数对离子浓度的影响,运用反距离加权插值算法并结合渗透系数分析了文登区浅层地下水海水入侵程度。结果表明文登沿海地区已经发生了极其严重的海水入侵现象,结合HFED可知咸水有向内陆继续扩散的趋势。研究结果对文登区地下水资源的利用和海水入侵的防治具有重要意义。另外本文是HFE-D和GQISWI在国内文献中的首次应用,为国内其他地区的海水入侵评价提供了参考。 相似文献
13.
实验测定了海水中氨基酸存在下Ｃｕ（Ⅱ）在ｒ－ＭｎＯＯＨ上吸附的等温线、Ｃｕ（Ⅱ）％－－ｐＨ曲线和Ｃｕ（Ⅱ）％－氨基酸深度曲线。结果表明，较低浓度氨基酸对Ｃｕ（Ⅱ）在ｒ－ＭｎＯＯＨ上吸附没有影响，而较高浓度氨基酸却起抑制作用，这主要是由于海水中Ｃｕ（Ⅱ）－氨基酸络合反应与ｒ－ＭｎＯＯＨ竞争Ｃｕ（Ⅱ）所致。此外，海水中较高浓度氨基酸只使Ｃｕ（Ⅱ）在ｒ－ＭｎＯＯＨ上吸附的表面分级离子交换稳定常数Ｋｉ（ｉ 相似文献
14.
研究用交流示波极谱测定海水中钾的方法。海水试样用NaOH调节pH约12,加入过量四苯硼化钠标准溶液,用微孔滤膜(或滤纸)过滤沉淀。收集游液,用TI(Ⅰ)标准溶液滴定过量的四苯基硼离子。方法回收率为99.5％。测定结果与四苯硼化钾重量法结果一致。海水中共存离子不干扰测定,并可用于海水及多种盐溶液中钾的测定。本法因其简便、快速、准确而易于推广。 相似文献
15.
Katsumi Hirose 《Marine Chemistry》1990,28(4)
Chemical speciation of particulate metals in seawater was examined theoretically. Mass balance considerations showed that the apparent conditional stability constant, defined for organically binding metals in suspended particles, coincides with the conditional stability constant determined for the corresponding metal-organic complexes dissolved in seawater. This hypothesis suggests that some metals, which are present as organic complexes (e.g. copper), are directly associated with particulate organic matter. Metals, whose free ion is buffered by organic and/or inorganic ligands, may be used as indicators of the presence of particulate organic matter in the marine environment. 相似文献
16.
为了解盐度渐变对黄条鰤(Seriola aureovittata)渗透调节的影响,设置自然海水(对照组盐度为29),5,10,15,20,35六个盐度梯度,并对不同盐度下幼鱼鳃丝Na~+/K~+-ATP酶活力、离子浓度、渗透压进行了检测和分析。结果显示:在盐度5～35,黄条鰤尿、血清、血浆的渗透压均随盐度升高而升高,盐度为35时渗透压均为最高,其中尿的渗透压显著高于血清和血浆渗透压。在盐度从29下降的过程中,鳃丝Na~+/K~+-ATP酶活力、离子浓度、渗透压呈现相似的变化规律,都随着盐度的降低而呈现总体下降的趋势;盐度从29升高到35时,各检测指标中仅有尿和血浆的K~+含量无显著变化(P0.05),其余均显著升高(P0.05)。实验结果表明,黄条鰤生存和繁衍的自然海水盐度29是幼鱼存活的适宜盐度,在略低的盐度20～29均能较快适应,说明在盐度渐变过程中,黄条鰤幼鱼对外界盐度变化有较强的调节能力。 相似文献
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18.
Influence of Salinity on pH and Aluminum Concentration on the Interaction of Acidic Red Soil with Seawater 总被引：1，自引：0，他引：1
Contamination of acidic red soil in the coastal areas of Okinawa Islands is a serious environmental problem. This study was conducted to examine the effects of the salinity on pH and aluminum concentration when the acidic red soil interacts with seawater. Acidic red soil from Gushikawa recreation center was fractionated into bulk soil, coarse sand and silt + clay. Different weights of each fraction were equilibrated with seawater solutions. The pH and concentrations of Al3+, Na+, K+, Ca2+ and Mg2+ were then analyzed in the extracts. The results showed a decreasing trend of pH with increasing soil to solution ratio while the extracted Al3+ revealed an increasing trend. The lowest pH values were 3.85, 4.06, 4.41, 4.66 and their corresponding highest Al3+ concentrations were 2.50, 1.01, 0.062 and 0.036 mmolL−1 in the seawater extracts, one-tenth seawater extracts, one-hundredth seawater extracts and one-thousandth seawater solution extracts, respectively. Mostly, the concentrations of Na+, Ca2+, Mg2+ and especially K+ decreased with increasing soil weight in the high salinities but showed the opposite trend in the low salinity samples. Potassium concentration decreased by 39%, 53% and 40% in the seawater extracts, one-tenth and one-hundredth seawater extracts but increased by 200% in one-thousandth seawater extracts. The coincidence of the increase in Al3+ and H+ concentrations, and the decrease of Na+, K+, Ca2+ and Mg2+ concentrations in the solutions suggests ion exchange/adsorption, while the increased patterns, particularly at low salinity could be attributed to the dissolution of the species from the soils. 相似文献
19.
通过离子色谱离线螯舍和ICP—MS对青岛市汇泉湾、太平湾、浮山湾采集的海水样品进行分析，得到了该海域表层海水中微量元素质量比的可靠数据，并对表层海水中微量元素的分布特征及其影响因素进行了探讨。将分析结果与国家海水标准进行比较表明，该海域海水中微量元素质量比符合国家一级海水标准。对该海域表层海水微量元素的分布特征的研究表明，近岸和远岸表层海水中微量元素的质量比差别很小，而不同于沿岸海区质量比高，离岸远处质量比较低的一般规律。其主要原因是该海域的人为污染程度小，再加上其特殊的海岸地形以及水动力条件，有利于溶解物质的扩散、迁移和稀释。 相似文献
20.
Hydrothermal chimney is a product of hydrothermal activity on the seabed. Chimney samples dredged from Jade hydrothermal area in Izena depression of the Okinawa Trough, are characterized by relatively enriched light rare earth elements (LREE) and strongly positive Eu anomalies. 87Sr/86Sr and 143Nd/144Nd of these samples are exactly between those of seawater and of acidic pumice, averaged at 0.708928 and 0.512292, respectively. These characteristics imply that the main source of hydrothermal sulfide at Jade area is possibly the undersurface acidic rocks. The mineralizing mechanism can be summarized as follows: Large amount of mineralized material would be leached out and LREEenriched hydrothermal solution would be subsequently produced as a result of thermo-chemical exchange reaction between acidic volcanic rocks and heated seawater that penetrated in advance from upper water mass. The spurting out from the seabed and quickly crystallizing in the seawater of hydrothermal solution are responsible for the formation of Cu-Zn sulfide and barite-amorphous SiO2 minerals that are characterized by enriched LREE and positively strong Eu anomalies. 相似文献