海水及鲈鱼中有机锡的GC-MS分析

对上海,天津及青岛海水及海鱼中三丁基锡和三苯基锡进行了ＧＣ－ＭＳ分析测定,分析了有机锡对海洋及生物污染的影响,实验回收率为７９％￣９３％,对日本环境厅国立环境研究所的认证标准参考物质的测定结果说明本实验有较高准确度。     

Fractionation of Oxygen and Hydrogen Isotopes at the Hydrate Gas forming in the Sea Sediments

The paper gives data on isotope composition of interstitial and near-bottom waters sampled in a region of gas-hydrate formation in the Sea of Okhotsk. The studies shows that heavy isotope of oxygen and hydrogen is used in gas-hydrate formation, with the result that isotope composition of its constitution water constitutes δ¹⁸O = +1.99‰, δD = +23‰ relatively to SMOW. Formation of autogenic carbonates leads to isotope exchange with interstitial water wich, in turn, changes its primary isotope composition in the direction of increasing of O-18 content. The near-bottom waters are isotope-light relatively to the SMOW standard and to the mean isotope composition of interstitial water in the studied region of gas-hydrate spreading.     

低温海水用钛基金属氧化物阳极的制备与性能

将Ti N纳米粉体与Ta Cl5正丁醇饱和溶液混合制得中间层涂覆液,通过热分解法在不同焙烧温度下得到了含有中间层的Ti/(Ti-Tax)O2/Ir O2电极,并与相同工艺下得到的传统Ti/Ir O2电极进行对比分析.采用X射线衍射和扫描电子显微镜对制备的电极进行了表征,通过循环伏安曲线、极化曲线和恒流加速寿命测试等电化学手段对电极性能进行了分析.结果表明,引入中间层可以使Ti/(Ti-Tax)O2/Ir O2电极400℃低温焙烧样品表层Ir O2结晶发育更好,得到了通常高温下才具有的典型龟裂纹形貌;相对于500℃高温焙烧样品,其在海水中的电化学活性表面积提高近6倍,在4℃和100 m A/cm2电流密度下的电极电位(1.37 V)降低100 m V,催化性能得到显著提高;同时加速寿命相对于传统的Ti/Ir O2电极提高10倍以上,是一种适用于低温海水环境的、具有较高活性和耐久性的新型阳极.     

2013年春夏季莱州湾海水环境要素的多元统计分析

根据2013年5月(春季)和8月(夏季)莱州湾海水环境要素的调查资料,通过主成分分析提取了3个主成分,累计表达原数据矩阵78.57%的信息,然后分别利用监测要素和主成分综合得分的层次聚类分析筛选出监控指标,并确定了水质污染状况及主要污染区域.结果表明,2013年莱州湾水质春季和夏季较差,导致水质状况恶化的主要要素是溶解无机氮,水质污染程度在时间和空间上存在较大差异,总体上春季海水污染程度高于夏季,莱州湾西侧和南侧处于严重污染或中度污染水平,因此常规监测中应重点关注化学需氧量、无机氮、叶绿素a和石油类这4个指标.     

Insights on the Electrocatalytic Seawater Splitting at Heterogeneous Nickel-Cobalt Based Electrocatalysts Engineered from Oxidative Aniline Polymerization and Calcination

Given the limited access to freshwater compared to seawater, a growing interest surrounds the direct seawater electrolysis to produce hydrogen. However, we currently lack efficient electrocatalysts to selectively perform the oxygen evolution reaction (OER) over the oxidation of the chloride ions that are the main components of seawater. In this contribution, we report an engineering strategy to synthesize heterogeneous electrocatalysts by the simultaneous formation of separate chalcogenides of nickel (NiS_x, x = 0, 2/3, 8/9, and 4/3) and cobalt (CoS_x, x = 0 and 8/9) onto a carbon-nitrogen-sulfur nanostructured network. Specifically, the oxidative aniline polymerization in the presence of metallic cations was combined with the calcination to regulate the separate formation of various self-supported phases in order to target the multifunctional applicability as both hydrogen evolution reaction (HER) and OER in a simulated alkaline seawater. The OER’s metric current densities of 10 and 100 mA cm⁻² were achieved at the bimetallic for only 1.60 and 1.63 V_RHE, respectively. This high-performance was maintained in the electrolysis with a starting voltage of 1.6 V and satisfactory stability at 100 mA over 17 h. Our findings validate a high selectivity for OER of ~100%, which outperforms the previously reported data of 87–95%.     

Evidence supporting the presence of dissolved dimethylarsinate in the marine environment

Experiments have been carried out to test the commonly held belief that the dissolved dimethylarsenic species present in marine waters is dimethylarsinate. By employing a novel combination of HPLC and cryogenic‐trap hydride generation atomic absorption spectroscopy (HG AA), the sensitivity limitations of conventional in‐line HPLC instrumentation can be overcome, permitting dimethylarsinate to be measured by HPLC at levels below 200 pg cm⁻³. A comparison of results obtained by this procedure with those obtained by direct cryogenic‐trap HG AA demonstrated that much of the dissolved dimethylarsenic present in the mouth of the Beaulieu River estuary (Hampshire, UK) had HPLC retention characteristics consistent with the presence of dimethylarsinate. Copyright © 1999 John Wiley & Sons, Ltd.     

荧光检测海水介质中的一氧化氮

基于2,3-二氨基萘(DAN)与一氧化氮(NO)在海水介质中生成荧光性2,3-萘酚三唑(NAT)来测定海水中NO.确定了荧光法测定NO的条件(λex=383 nm,λem=410 nm)、温度和时间对DAN捕集NO的影响,以及DAN溶液对捕集NO的影响.测得NO浓度与其荧光强度之间呈线性关系,线性范围1.4～1400 nmol/L, r=0.9985,P<0.0001;检出限1 nmol/L (S/N=3);相对标准偏差1.63%(14 nmol/L NO);不存在介质干扰.同样条件下与NaOH为介质的荧光法相比,本方法将检出限提高了1个数量级.结合吹扫-捕集检测出青岛石老人(36°05′46″ N; 120°29′40″ E)海水中NO浓度为(0.12±0.01) nmol/L,可用于监测硝普钠在海水中释放NO的规律.     

CrAlN涂层海水环境腐蚀磨损行为研究

采用多弧离子镀在316不锈钢上沉积Cr Al N涂层,用X射线衍射仪(XRD)和扫描电子显微镜(SEM)表征涂层的成分和结构,纳米压痕和划痕仪分别测试涂层的硬度和结合力.通过球-盘往复式摩擦磨损试验机在海水环境下测试涂层腐蚀磨损性能,并用电化学工作站实时监测其摩擦过程中的电化学特性.结果表明:Cr Al N在有摩擦的条件下,涂层极化曲线的阳极区域存在较为明显的钝化区,抑制了涂层进一步腐蚀.在阳极电位下,涂层的摩擦系数随着加载电位的增加显著降低.随着加载电位的升高,涂层的磨损量也相应地增大.在阳极电位0.5 V下的磨损量是阴极电位–1 V下的2.99倍.在0 V时,磨损促进腐蚀的损失量,约占总损失量的13.71%.在–1 V,–0.5 V,–0.25 V,OCP,0 V下的磨损机理主要为磨粒磨损和塑性变形,而在0.25 V,0.5 V下的磨损机理主要为疲劳点蚀.     

一种新的海洋浅层水合物开采法——机械-热联合法

天然气水合物是国家的战略能源之一.天然气水合物分解相变使其开采难度高于常规化石能源.国际天然气水合物试验性开采表明通过降压、注热等方法难以满足商业化开采的需求,尤其在水合物位于浅层、软土情况下,持续稳定且高效率的热量供给是其瓶颈.天然气水合物机械-热联合开采是一种新概念模式,即通过粉碎水合物沉积物通过管道输运并在内部分解,这样既增加了传热的表面积,又利用海水热量和对流传热提高了能量供给效率.分析表明:利用该方法开采时水温过高会导致水合物分解过快而产生不稳定流,温度过低又导致水合物二次生成或结冰;水流流速既要能使被粉碎的水合物沉积物颗粒悬浮和流动,又不能导致流动失稳.为了实现高效安全的机械-热水合物开采,经过初步分析提出原位水合物地层粉碎的颗粒直径设定在0.1~1.0 cm之间,控制水流速度为0.22~0.67m/s,温差保证在5K以上,混合物中水的体积分数大于0.85.      

Application of seeded batch crystallization methods for reduction of the scaling tendency of seawater – A study of growth kinetics of calcium carbonate in seawater

The objective of this study is to evaluate the applicability of a seeded batch crystallization method as a pre‐treatment stage to the reduction of the the scaling potential of seawater. The crystallization process of calcium carbonate in supersaturated seawater is studied experimentally in a seeded batch crystallizer. Results show that the initial pH value of seawater must be adjusted to be in the range of 8‐9. Calcite seeds will not have the potential to start the growth process in seawater at he the normal pH (7.36) compared to the above mentioned range. The growth kinetic parameters are determined from the measured desupersaturation curves. It is found that the growth process of calcite is controlled by surface integration step. The growth rate of calcite increases with increasing temperature and seeding ratio (up to 1 g/L), while it decreases with increasing the salinity of seawater. Crystals of calcite morphology are found to be growing faster than seeds of aragonite morphology. Stirrer speed has no distinct effect on the growth rate of calcite in seawater. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)