聚氨酯泡沫富集-ICP-AES法测定土壤及水系沉积物中铊含量

本文建立了一种以聚氨酯泡沫富集-ICP-AES法测定土壤及水系沉积物中铊含量的分析方法,利用正交实验,确定最佳实验条件,方法的检出限为0.01mg/L,经对土壤及水系沉积物成分分析标准物质的检测,结果与推荐值相符,相对误差小于10%,相对标准偏差(RSD,n=10)在1.9%-4.9%之间。     

运用测汞仪快速测定水系沉积物中的总汞

建立了采用测汞仪快速测定水系沉积物中总汞的分析方法,并进行标准样品及实际样品测定验证。结果表明,实际样品的加标回收率分别为97.0%~107.2%和98.9%~111.3%,相对标准偏差为1.2%~1.8%。该方法具有无需消解、测定快速、准确度高的特点,是一种测定水系沉积物中总汞的简便快捷方法。     

氢化物发生-原子荧光光谱法测定水系沉积物中铋和汞

水系沉积物试样用盐酸-硝酸-水(3+1+4)混合溶液溶解,氢化物发生-原子荧光光谱法测定铋和汞的含量。对介质酸度、硼氢化钾浓度、负高压和灯电流等影响铋和汞测定因素进行了试验并予以优化。铋和汞的检出限(3S/N)分别为0.02,0.01μg.L-1,相对标准偏差(n=11)均小于0.5%。应用此法分析了水系沉积物标准样品,测定值与推荐值相符。     

自动消解仪—ICP法测定水系沉积物中6种重金属元素

建立了自动消解仪-电感耦合等离子体发射光谱法(ICP-OES)同时测定水系沉积物中Cu、Zn、Ni、Cr、Pb、Co六种元素含量的方法。该方法的相关系数好、检出限低。方法经国家标准物质(GBW07361)验证,准确度和精密度均能达到环境监测分析的要求,为水系沉积物中重金属元素含量的测定提供了简单可靠的分析方法。     

聚氨酯泡沫富集-电感耦合等离子体原子发射光谱法(ICP-AES)测定土壤及水系沉积物中铊含量

建立了一种以聚氨酯泡沫富集-电感耦合等离子体原子发射光谱法(ICP-AES)测定土壤及水系沉积物中铊含量的分析方法,利用正交实验,确定最佳实验条件,方法的检出限为0.01mg/L,对土壤及水系沉积物标准物质的测定结果与推荐值相符,相对误差小于10%,相对标准偏差(RSD,n=10)在1.9%~4.9%。     

电感耦合等离子体原子发射光谱法(ICP-OES)测定水系沉积物中6种重金属元素

建立了自动消解仪消解-电感耦合等离子体原子发射光谱法(ICP-OES)同时测定水系沉积物中Cu,Zn,Ni,Cr,Pb,Co 6种元素含量的方法。方法中6种元素的检出限为0.000 2~0.02mg/L,工作曲线的相关系数均大于0.999。方法经国家标准物质(GBW07361)验证,准确度和精密度均能达到环境监测分析的要求,为水系沉积物中重金属元素含量的测定提供了简单可靠的分析方法。     

厦门西海域表层沉积物中稀土元素分布特征

以厦门西海域表层沉积物为对象,研究了沉积物中稀土元素(REE)的分布特征.结果表明:厦门西海域沉积物中REE含量为125.71～206.02 μg·g-1,西部港湾区的8号和九龙江口的2号采样点REE含量较高,且轻稀土占绝对优势.REE含量随沉积物粒级呈有规律的变化,REE含量最高的是＜63μm的粒级,最低的是250 μm的粒级;沉积物经球粒陨石标准化后,各粒级REE总体配分曲线相近,均表现为明显的Eu亏损和Ce亏损,且＜63μm粒级亏损尤为严重.Eu与Ce异常平均值均小于黄河流域和长江流域沉积物;＜63μm粒级的沉积物中轻重稀土分馏程度最高,但在其他三种粒级沉积物中由粗到细分馏程度逐渐降低.分馏现象表明细粒级沉积物轻重分馏较粗粒级明显.与当地土壤稀土元素背景值比较,沉积物主要来自厦门西海域本地的土壤.     

硅胶-TBP反相萃取层析分离测定水系沉积物及岩矿中微量钼和锡

本文研究了钼与PV-CTMAB的显色反应,结果表明该体系灵敏度虽高,选择性却很差。为此,本文采用硅胶-TBP反相萃取层析法,使Mo、Sn与Ti、W、Ge、Cu、Pb、Zn、Ni、Mn、Fe等分离,提高了方法的选择性.并应用于含上述诸多离子的复杂试样——水系沉积物、岩矿中微量Mo、Sn的测定,取得满意的结果。     

激光剥蚀电感耦合等离子体质谱快速分析水系沉积物主量及痕量元素

基于193 nm ArF准分子激光器与四级杆电感耦合等离子体质谱联用,我们描述了固体样品分析中定量校准的基本原理,提出了一个简单,快速、同时分析水系沉积物中主量及痕量元素的方法:无内标校准法.分析了水系沉积物中主、痕量共52种元素.对水系沉积物标准参考物质GSD-4的分析,结果与推荐值具有良好的一致性,相对误差<15%的有46个元素,<10%的有36个元素;大多数元素的相对标准偏差<10%.结果表明,运用多个外标和无内标校准法,能够对水系沉积物样品进行多元素快速、同时分析,分析结果的准确度优于传统的外标-内标结合校准法.     

天然水源中微量铀钍含量与摄入量研究

分析了居民饮用水及其天然水源中微量铀，钍的含量，并与尿液中铀，钍含量进行了比较。结果表明，上海地区天然水源在国家规定的允许范围内，接近于尿液中铀，钍的日排出量。     

Ore Leashing Processing for Yellow Cake Production and Assay of their Uranium Content by Radiometric Analysis

In this study, Ore granite samples were collected from Gattar site for leashing of yellow cake. The process involves heap leaching of uranium through four main steps; size reduction, leaching, uranium purification, and finally precipitation and filtration. The separation process has been given in details and as flow chart. Gamma spectrometry based on HpGe detector and energy dispersive X‐ray (EDX) were used to assay uranium content and activity before and after separation. The uranium weight percentage value as measured by EDX were found to be 40.5 and 67.5 % before and after purification respectively. The results of the calculations based on gamma measurements show high uranium activity and the uranium activity ratios values are 0.045 ± 4.9, 0.043 ± 4.7, and 0.046 ± 2.3 %, before purification, whereas these values were found to be 0.050 ± 3.3, 0.049 ± 3.3, and 0.050 ± 2.7 %, after purification, respectively. The results are discussed in details in the paper.     

Evaluation of As and Sb Mobility in Contaminated Stream Sediments

Single and sequential extraction procedures were applied to four sediment samples collected from an industrially polluted region of Eastern Slovakia. A sequential extraction procedure (SEP) for sediments recommended by the IRMM (Institute for Reference Materials and Measurements) – was applied and used as a reference extraction method. Single-step extraction (for soils) with 0.05 mol L⁻¹ ethylenediaminetetraacetic acid (EDTA) was slightly modified for this study of sediments. The removal ability of “Na₂EDTA extraction” was compared with the SEP recommended by the IRMM. After optimisation, the elements’ contents extracted into Na₂EDTA were in good agreement with the sum of the 1^st, 2^nd, 3^rd and 4^th step of SEP for As and Sb. Therefore Na₂EDTA extraction can serve as a supplementary test to the SEP recommended by the IRMM (under locally tested conditions). Alternatively, optimised extraction of sediments in chelating agents could be applied as an economically interesting and time-saving supplementary test to routinely used SEPs. This paper describes the sample preparation and the analytical results for each extraction step and compares the results with those of total element analyses (performed by an independent method) for As and Sb.     

赝势平面波计算铀及铀化合物结构研究

Ultrasoft pseudopotential was generated for uranium and the plane waves pseudopotential formalism was used to study its crystal structures at zero temperature as a function of pressure. The alpha phases of uranium were fully relaxed. The zero-pressure zero-temperature equilibrium volumes and bulk moduli are consistent with previous calculations, and in excellent agreement with the experiment. This is also the case for cell parameters and pressure-induced phase transitions. In the calculation of NaCl and CaF2 structure type of compound of uranium, the difference of theoretical lattice constant and the experimental value is less than 3%. For UO2+x the trend of the lattice shinking with the x value increase is in accord with the experiment. For large U2C3 and U2N3 complex cells the difference of theoretical lattice constant and the experimental value is less than 3%, and the difference of coordination of atom is less than 5%.     

沱江流域Pb、Cd的环境污染化学行为研究

对沱江流域金堂、简阳、内江三地河流沉积物中重金属Pb和Cd含量及其时空分布特征进行了研究,并结合与沉积物中Fe、Mn和LOI等参数的相关性对河流沉积物中Pb和Cd地球化学性质进行了初步的分析和讨论。结果表明,沱江三地沉积物中Cd、Pb含量不高,平均含量按上、中、下游次序逐渐降低;从垂向分布行为看,Cd在上游金堂地区上部含量高于下部,而中、下游两地则相反,而Pb均随着深度的增加而减少,反映了近年来人类活动所产生Pb污染的加剧;TOC、沉积物性状和上覆水体中的物化性质对于其垂向分布有着较大影响。对于深入揭示水环境中重金属的环境地球化学循环有着重要的指导意义。     

Determination of the Uranium(VI) and ‐(IV) Species in Uranium Ores

The determination of the two species of uranium(VI and IV) present in 6 uranium ores was studied in relation to the chemical and mineralogical composition, humidity, and pH of the samples taken over from the mine. X‐ray diffraction studies, performed on the uranium ores in powder form allowed to establish their mineralogical composition. Thechemical analysis pointed out the presence, besides the two uranium species, of some microelements able to influence the U^VI/U^IV ratio in minerals and to leach out U^VI as uranyl ions from the corresponding minerals.     

Uranium and fluorine cycles in the nuclear industry

In the nuclear fuel cycle, fluorine is currently not recycled. In this paper, we have examined the possible routes to implement such a cycle. Because UF₆ deconversion requires an excess of water, aqueous HF is produced. Two alternatives are then possible: either separate HF from H₂O or recycle the HF-H₂O in the deconversion process. Alternative UF₆ deconversion could also be implemented to resorb the high UF₆ inventory.     

胶州湾表层沉积物重金属分布特征及污染评价

为评价胶州湾跨海大桥的建设对其沉积物中重金属分布的影响,于2009年7月采集了黄海胶州湾11个站位的表层沉积物,测定了沉积物中的重金属含量.结果显示,胶州湾沉积物重金属污染程度较低,Hg、Cu、Pb、Zn、Cd、Ni、Co、Mn 8种重金属的平均含量分别为0.031、19.05、12.7、51.14、0.055、17....