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1.
在海水pH(7—8)条件下,硫主要呈HS~-离子存在。海水中硫化物的测定方法有比色法、离子选择性电极法和阴极溶出伏安法等。比色法测定的灵敏度较低,离子选择性电极可直接测定1×10~(-6)M的硫化物浓度,若与预富集法相结合测定的硫化物的最低浓度为10~(-9)M。近年来,冯建兴等人应用微库仑计测定了淡水水体中超痕重的硫化物’检出下限可达0.2ppb。但尚未见到用微库仑计测定海水硫化物的报  相似文献   

2.
对臭氧总残留氧化物(TRO)常用3种检测方法(碘化钾-N,N-二乙基-1,4-苯二胺(KI-DPD)分光光度法、硼酸碘化钾(H3BO3-KI)比色法、靛蓝二磺酸钠(IDS)分光光度法)进行了比较研究。结果表明:在0~0.5 mg/L的TRO浓度范围内,KI-DPD分光光度法和H3BO3-KI比色法线性关系良好,检出限分别为0.040 mg/L和0.034 mg/L,并且这两种测定方法的准确性和重复性较佳,相对标准偏差(RSD)均小于5.0%,低于传统碘量法;而IDS分光光度法只有在高浓度臭氧海水样品(0.6~1.2 mg/L)检测时,RSD才小于5.0%,且测定浓度明显低于另外两种方法。故对于海水养殖水体中的TRO检测,KI-DPD分光光度法和H3BO3-KI比色法均准确有效,并且H3BO3-KI比色法在检测操作上更为简便快捷。  相似文献   

3.
海岸带盐度过渡区域水体中氮、磷的准确测定对陆海统筹及海岸带管理起着至关重要的作用。为探究盐度对氮、磷测定准确度的影响,进而明确河口海岸带淡水-咸水盐度过渡区不同形式氮、磷测定方法的选择依据,分别采用淡水和海水的相关国家标准方法,测定不同盐度下不同质量浓度氮、磷的人工海水和天然海水水样中氨氮、亚硝氮、总氮、活性磷酸盐和总磷的质量浓度。结果表明,盐度对某些氮、磷的淡水法和海水法测定结果有一定程度的影响。对氨氮的测定,当S≤4.0时淡水法或海水法均可准确测定水体中的氨氮,S>4.0时应对水样进行pH 调整预处理后用海水法进行测定;对亚硝氮的测定,淡水法和海水法的测定结果无明显差异;对总氮的测定,当S≤5.0时应采用操作简单、测定准确的淡水法测定,S>5.0时应采用海水法。对水体中的活性磷酸盐的测定,在低盐低磷(S≤35.0且ρPO3-4 ≤0.2mg·L-1)的情况下盐度对淡水法和海水法测定结果的影响微乎其微,而对于高盐高磷(S>35.0且ρPO3-4 > 0.2mg·L-1)的水样选择灵敏度更高的海水法测定更准确;对总磷的测定,选取海水法测定准确度更高。研究结果为海岸带水体不同形式氮、磷质量浓度的准确测定与方法选择提供了科学依据。  相似文献   

4.
探讨次氯酸钙和二氯异氰尿酸钠两种代表性含氯消毒药物,为含氯消毒剂应用于细菌性虾病的防治提供理论依据。实验表明:有效氯在海水中的丧失随温度上升、pH值下降而加速。常见对虾病原菌对有效氯非常敏感,有机物增加、pH值上升使杀菌率下降。两种药物对实验中国对虾的48h半致死浓度为2.74~2.88mg/L有效氯。长期施以高于安全浓度的药物对实验虾之存活率、增长率等指标无不良影响,施药组发病率远远低于对照组。  相似文献   

5.
南海东北部海水中N2O分布与产生机制的初步研究   总被引:6,自引:0,他引:6  
2004年9月18—10月4日调查了南海东北部海水中氧化亚氮(N2O)浓度。表层海水中的N2O浓度平均值为8.40±0.79 nmol.L-1,饱和度平均为123%±11.6%,是大气N2O的源。不同区域表层海水中的N2O浓度存在明显差异,在水深200m层呈现南高、北低的分布特征。各层次海水中的N2O浓度均处于过饱和状态,N2O浓度由海水表层到底层呈上升趋势。ΔN2O与AOU间有显著的正线性相关性,说明海洋内部的硝化作用是产生N2O的主要机制。N2O的海-气通量平均值为0.72±0.36μmol.(m2.d)-1。  相似文献   

6.
控释海水植物肥中氮、磷的测定   总被引:1,自引:0,他引:1  
为评价控释肥的肥效,探讨、建立了相应的氮、磷测定方法。用硫酸作消解剂,消解液可以同时被用来测定氮、磷。钼锑抗坏血酸络合物作为显色剂,用紫外可见分光光度计测定磷的浓度;用改良式微量凯氏定氮蒸馏滴定法测定氮的含量。该方法灵敏、准确,易操作。用海水浸泡自制的控释海水植物肥样品(编号:MRF-0201.中速型),运用建立的氮、磷测定方法测定浸取液中的氮、磷含量,实验证明该方法可以用于研究控释海水植物肥在海水中的氮、磷的化学动力学行为。  相似文献   

7.
物质海 -气通量计算新建议中将物质海 -气通量计算公式 F=K(CL- b Cg)中的 CL 用CL ( SML ) 代替。本文着重于对公式中质量迁移系数 K的讨论。在测定了海水微表层、次表层水粘度并同时测定了其它一些化学参量基础上 ,得出如下结论 :海水粘度与盐度、碱度有一定相关性 ;微表层与次表层海水的粘度变化小于 3%。因此 ,海水微表层效应影响 K值 ,与海水微表层效应影响物质浓度相比 ,可以不考虑。  相似文献   

8.
本文选择酒石酸消除海水基体对铜信号的干扰,用塞曼石墨炉原子吸收法直接测定海水中的铜。从Cu的原子化曲线可知,加入酒石酸后,背景值减小,Cu原子吸收信号增强,且出现时间提前,表明酒石酸是有效的海水基体改进剂。用P.E.Z3030光谱仪测得双蒸水及海水中的元素Cu的特征质量(m。)分别为12.5pg及12.7pg;检测限分别为0.18μg/L和0.19μg/L,表明基体效应已消除,符合海洋监测要求。可用纯Cu标准溶液作校正曲线,以国家海洋局的两个标准海水样品中的Cu评定本法的准确度,相对偏差为0及-4.6%,与经典的经富集后的FAAS法的结果相比,相对偏差在3.0—6.5%范围内。用不同类型的光谱仪测定了30个海水样品,回收率在89—104%范围内。本法操作简便、快速。  相似文献   

9.
本文首次采用 Nafion和 Co(salen) /Nafion修饰铂电极测定海水中的 NO,对实验条件进行了选择 ,确定了最佳实验条件 ,即反应池通氮除氧 30 min,富集时间为 4min。同时用线性扫描法对海水中的 NO进行测定 ,测得海水中 NO的浓度与氧化峰电流之间有一定线性关系。对 Nafion修饰电极而言 ,线性范围 1~ 76.9μmol/L,R2 =0 .991 6,检出限为 1 μmol/L。同时对 2种方法修饰的铂电极进行了比较 ,即当 NO浓度在 1 0 -6mol/L数量级时 2种电极基本上无差别 ,而在 1 0 -7mol/L数量级时 Co(salen) /Nafion修饰电极要明显优于 Nafion修饰电极  相似文献   

10.
海水苦卤中可溶性糖的测定   总被引:3,自引:0,他引:3  
建立了一种海水苦卤中可溶性糖的测定方法。研究确定了苯酚-硫酸法测定海水苦卤样品中可溶性糖的最佳实验条件。在加入苯酚60mg、90℃水浴加热20min的条件下,显色体系在490nm处的吸光度达到最佳值,糖的浓度在1—100μg.ml-1范围内符合比尔定律,线性相关系数为0.999 7。该方法具有简便、快速、稳定性好、干扰因素少的特点,且样品基本无需预处理。用所拟方法对广东省徐闻县盐场制盐苦卤中的可溶性糖进行测定,相对标准偏差为1.73%(n=6),加标回收率在94.80%—102.70%之间,结果满意。应用该方法还成功测定了生态型人工海水添加剂———苦卤提取物中糖的含量。  相似文献   

11.
This article reviews information recently available from existing marine and coastal mining for responses to environmental issues affecting marine mining at different depths. It is particularly but not exclusively concerned with those issues affecting seabed biodiversity impact and recovery. Much information has been gathered in the past 10 years from shallow mining operations for construction aggregate, diamonds, and gold, from coastal mines discharging tailings to shallow and deep water, and from experimental deep mining tests. The responses to issues identified are summarized in a series of eight tables intended to facilitate site-specific consideration. Since impacts can spread widely in the surface mixing layer SML, and can affect the biologically productive euphotic zone, the main issues considered arise from the depth of mining relative to the SML of the sea. Where mining is below the SML, the issue is whether it is environmentally better to bring the extraction products to the surface vessel for processing (and waste discharge), or to process the extraction products as much as possible on the seabed. Responses to the issues need to be sitespecific, and dependent on adequate preoperational environmental impact and recovery prediction. For deep tailings disposal from a surface vessel, there are four important environmental unknowns: (1) the possible growth of "marine snow" (bacterial flocs) utilizing the enormous quantities of fine tailings particles (hundreds or thousands of metric tons per day) as nuclei for growth, (2) the possibility that local keystone plankton and nekton species may migrate diurnally down to and beyond the depth of deep discharge and hence be subjected to tailings impact at depth, (3) the burrow-up capability of deep benthos and their ability to survive high rates of tailings deposition, and (4) the pattern and rate of dispersion of a tailings density current through the deep water column from discharge point to seabed. Actions to obtain relevant information in general and site-specifically are suggested.  相似文献   

12.
Particle fluxes were measured 7 m above the sea bottom during the predisturbance, disturbance, and postdisturbance periods by using time series sediment traps attached to seven deep-sea moorings deployed in the INDEX experiment site in the Central Indian Basin. The predisturbance particle fluxes varied between 22.3 to 55.1 mg m -2 day -1 . Increased and variable particle fluxes were recorded by the sediment traps during the disturbance period. The increase observed was 0.5 to 4 times more than the background predisturbance fluxes. The increases in particle fluxes (~4 times) recorded by the sediment trap located in the southwestern direction (DMS-1) were the greatest, which could be the result of preferential movement of resuspended particles generated during the deep-sea benthic disturbance along the general current direction prevailing in this area during the experimental period. Also, the traps located closer to the disturbance area recorded greater fluxes than did the traps far away, across the Deep Sea Sediment Resuspension System path. This variability in recorded particle fluxes by the traps around the disturbance area clearly indicates that physical characteristics such as grain size and density of the resuspended particles produced during the disturbance had an important effect on particle movement. The postdisturbance measurements during ~5 days showed a reduction in particle fluxes of ~50%, indicating rapid particle settlement.  相似文献   

13.
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths.  相似文献   

14.
海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明:土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。  相似文献   

15.
The advanced piston corer (APC) has been used by the Ocean Drilling Program since 1985 for recovering soft sediments from the ocean floor. The pullout force measured on extracting the core barrel from the sediment is shown to correlate with the average shear strength of the sediment core measured in the ship's laboratory. A simple rule of thumb is derived relating the shear strength of the sediment to the pullout force. Multiple APC holes at individual sites allow the consistency of the pullout measurements to be assessed. The effects of different operational procedures during APC coring are also explored. Although generally applicable, the correlation between pullout force and laboratory measurements of shear strength breaks down for some APC holes, possibly because of the disturbance of some sediment types during the APC coring process. A better understanding of the physical process of APC coring, and its effect on the properties of the sediment both inside and immediately outside the core barrel, would indicate what confidence can be put on the measurement of pullout force as a way of evaluating the in situ shear strength of deep sea sediments.  相似文献   

16.
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone.  相似文献   

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《海洋学报(英文版)》2014,(11):161-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology,  相似文献   

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