钇—5—Br—PADAP—CPC—OP显色反应的研究

研究了钇(Ⅲ)-5-Br-PADAP-CPC-乳化剂OP混合体系的光度特性,在pH7.5～9.8范围内,显色体系在580nm处有最大吸收峰,空白值低,对比度(Δλ)较高,摩尔吸光系数ε为1.0×10~5。配合物组成Y:5-Br-PADAP:CPC为1:4:3,形成稳定常数(logβ)为9.84。在0—45μg Y/50ml范围内服从比尔定律。该法已成功地应用于测定Fe-Cr-Al合金和矿物中痕量钇。     

铟—1—苯基—3—甲基—4—苯甲酰基吡唑啉酮—5—安替比林体系络合吸附波？…

在ＰＨ４．５的ＨＡｃ－ＮａＡｃ介质中,Ｉｎ－１－苯基－３－甲基－４－苯甲酰基吡唑啉酮－５（ＰＭＢＰ）－安替比林体系于－０．５７Ｖ处产生一良好的极谱波。Ｉｎ在０．０１－０．５ｍｇ／Ｌ与波高呈线性关系。     

Pb—Sn—Fe—Sb—S体系相关系

用抽空石英管法研究以Fe_(0·96) Sb_(2·04) S_(4·12)为投影顶点,8×(PbS-SnS-SnS_2)为投影平面的Pb-Sn-Fe-Sb-S体系的相图表明,由于Pb(?)Sn~(2+)之间互相取代,500℃时辉锑锡铅矿固溶体中Sn~(2+)变化范围(以单位分子式11个金属原子总数为计量)是0—4.8个原子,400℃时则为0—4.0个原子。同时,Sn~(4+)变化范围是1.3—2.3个原子和1.5—2.1个原子。圆柱锡矿固溶体变化范围较小。500℃时Sn~(2+)变化范围是0.4—1.8个原子,400℃时为0.5—1.7。Sn~(+4)变化范围则分别为3.2—4.2个原子和3.3—4.2个原子。变更Fe含量(0.81—1.09)及Sb含量(1.83—2.29)进行的几组合成实验表明,上述两个矿物中Fe、Sb含量变化范围很小,不超过±0.15个原子。辉锑锡铅矿固溶体可与方铅矿、块硫锑铅矿、针硫锑铅矿、硫锡铅矿、硫锡矿、圆柱锡矿等形成平衡结线。而圆柱锡矿不与方铅矿、硫锡矿、硫锡铅矿形成平衡结线,但可与辉锑矿、SnS_2及上述其他矿物形成平衡结线。结合锡的硫化物及氧化物(锡石)热力学稳定场计算表明,在本体系内辉锑锡铅矿在300℃时稳定区的硫活度在lga_(s2)=-20(atm)附近,氧活度小于lga_(o2)=-40(atm),而圆柱锡矿稳定区硫活度大于lga_(s2)=-10(atm)。     

4—（2—羟基—4—硝基苯偶氮）—1—苯基—3—甲基吡唑啉酮与钍的显色反应

在pH为 2～ 3的HAc介质中 ,4 - ( 2 -羟基 - 4 -硝基苯偶氮 ) - 1 -苯基 - 3-甲基吡唑啉酮 (HNAPMP)与钍反应生成 2∶1的稳定络合物 ,λmax=540nm ,ε=4 .96× 1 0 4L·moL- 1·cm- 1,Th质量浓度在 0～ 2 .8mg/L内符合比尔定律。方法用于钍钨合金中钍的测定 ,相对标准偏差 (n =5)小于 1 % ,加标回收率为 97%～ 1 0 2 %。     

1—（2—羟基—3,5—二硝基苯）—3—4（4—苯基—2—噻唑）—三氮稀的合成及其与镍的显

合成了新试剂 1 - (2 -羟基 - 3,5-二硝基苯 ) - 3- (4-苯基 - 2 -噻唑 ) -三氮烯 ,研究了在表面活性剂TritonX - 1 0 0存在下 ,它与Ni2 的显色反应。结果表明 ,在 pH 6.0～ 7.5时 ,Ni2 与该试剂形成配合物 ,其最大吸收峰位于 51 5nm处 ,摩尔吸光系数为 1 .0 8× 1 0 5 L·mol- 1 ·cm- 1 。Ni2 在 0～ 0 .4mg/L内符合比尔定律。方法已用于矿物、合金、钢样中微量镍的测定 ,结果与原子吸收法相符 ,相对标准偏差RSD <5% (n =6)     

2—[2‘—（6—甲氧基—苯并噻唑）—偶氮]—1,8—二羟基萘—3,6—二磺酸的合成及？…

合成了新的杂环偶氮变色酸类试剂--2-[2'-(6-甲氧基-苯并噻唑)-偶氮]-1,8-二羟基萘-3,6-二磺酸,并系统探讨了在pH 4.5的邻苯二甲酸氢钾-NaOH介质中显色试剂与钛的显色反应特性.结果表明,在溴化十六烷基吡啶存在下,试剂与Ti(Ⅳ)形成2:1的络合物,显色反应15 min完全并至少稳定4 h,最大吸收波长为670 nm,表观摩尔吸光系数达1.67×105 L.mol-1.cm-1,钛的质量浓度在0～400 μg/L时符合比尔定律.用拟定的方法测定了硅砖等标准物质中的Ti(Ⅳ),所得结果与标准值的相对误差均小于4%,RSD(n=5)小于3.5%.     

省级中心镇——杜桥镇

临海市杜桥镇位于浙江沿海中部,台州湾北岸,全镇陆地面积186平方公里。建成区面积13．6平方公里。户籍人口20．7万。2010年,全镇实现工农业总产值157．65亿元,     

Surveying the anthropogenic impact of the Moldau river sediments and nearby soils using magnetic susceptibility

Measuring magnetic susceptibility is a method which is used to estimate the amount of magnetic particles in soils, sediments or dusts. Changes in magnetic susceptibility can be due to various reasons: input from different sources of sediments, e.g. from different soils or rocks, atmospheric fallout of anthropogenic dusts containing magnetic particles produced by fossil fuel combustion, steel production or road traffic. In the case of river sediments, input from the catchment is of primary significance. The main aim of this investigation was to test the potential of magnetic susceptibility screening in identifying the effect and significance of anthropogenic activities in an area with complex geological conditions. We investigated the magnetic susceptibility of riverbed sediments of the largest river of the Czech Republic, the Moldau river. Besides that, the magnetic signal of nearby topsoils as well as of outcropping bedrocks in the vicinity of the river was examined. In the upper 300 km of the river, the magnetic enhancement of the river sediments can be linked to anthropogenic activities. Positive correlations were found in the river sediments between the contents of Cu and Zn and magnetic susceptibility, while Fe, Mn and Ni did not show a correlation with magnetic susceptibility. However, the major geogenic magnetic anomaly in the area around the Slapy dam has made it impossible to unambiguously interpret the magnetic signal in terms of anthropogenic impact in the last 80 km downstream.     

Field and dual magnetic susceptibility proxies for heavy metal pollution assessment in the urban soil of Al-Karak City, South Jordan

A total of 115 urban soil samples collected on grid bases from Al-Karak, South Jordan, were investigated for their field and dual-frequency magnetic susceptibility (χ _field, χ _d) and heavy metal content using Bartington susceptibility meters and ICP-MS. The upper soils have higher magnetic susceptibility values than lower soils, and large particles contain more heavy metals and higher magnetic susceptibility than smaller particles. This might be attributed to the lack of pedogenesis due to arid climate influence. Within the upper soil all heavy metal showed positive significant correlation with upper soil low-frequency χ _dlf. This was evident from the distribution maps produced by Surfer 9.0 for χ _dlf and heavy metals. The results showed that higher χ _dlf is associated with traffic-dominated sites more than other areas. The frequency-dependent susceptibility (χfd %) falls between 2 and 10 %, which indicate the presence of admixture of fine supermagnetic particles. Mildly correlation exists between χfd % and χ _dlf, which implies that soils contain anthropogenic multi-domain grains. Selected samples have been analyzed for their mineral constituents; the results indicate the presence of magnetite as the main magnetic mineral. This confirms the anthropogenic source of pollution mainly from the vehicle-related materials. The results indicate the applicability of magnetic susceptibility for pollution detection.     

The theory of spontaneous emission by electrons during their motion along the quantizing magnetic field of a star

The quantum motion of non-relativistic and relativistic electrons in the presence of constant magnetic fields at the surfaces of magnetic stars, magnetic white dwarfs, and pulsars is considered. The quantizing magnetic-field strengths for charged particles with specified energies are determined. The quantum motion of these particles in a plane perpendicular to the magnetic field is accompanied by spontaneous radiation due to electron transitions from higher to lower discrete energy levels, right down to the ground state. In the non-relativistic case, this emission is monochromatic. In the non-relativistic case, various frequencies are emitted, but lie within an order of magnitude of each other. The electron kinetic energy along the magnetic field varies from zero to a maximum value, due to the one-dimensional character of the motion along the field, between each pair of potential barriers corresponding to the discrete energy levels. The results may be relevant to describing gamma-ray flares of pulsars.     

Environmental magnetic studies on surface sediments: a proxy for metal and hydrocarbon contamination

Visakhapatnam is one of the major port cities, and it is developed into a hub of many large- and medium-scale industries. Due to growing industrialization and urbanization, coast is vulnerable to both organic and inorganic micro-pollutants. Twenty-five surface sediments were collected along the Visakhapatnam coast for the measurement of texture size, petroleum hydrocarbons, trace metals and environmental magnetic parameters. The percentage of coarser particles was more in the northern region, whereas the percentage of fine particles was increased toward south. Elevated levels of petroleum hydrocarbons and trace metals were attributed due to marine and land-based sources, in particular, those were due to shipping activities, treated and partially treated sewage and industrial wastes. The concentrations of trace metals, petroleum hydrocarbons and magnetic minerals were decreased from nearshore to seaward. Our results revealed that the magnetic mineralogy is dominated by magnetite with a small proportion of hematite, and the grain size of magnetic minerals was in the range of pseudo-single domain to multidomain nature with detrital origin. From the principal component analysis, the magnetic concentration and mineralogy-dependent parameters co-vary with the heavy metal and PHC concentrations, suggesting that the inputs of magnetic minerals, petroleum hydrocarbons and heavy metals in the Visakhapatnam shelf sediments were derived from the same anthropogenic sources. Thus, the large magnetic dataset can be used to reduce the number of chemical analysis; hence, environmental magnetic parameters were used as a proxy for both organic and inorganic micro-pollutants.     

Magnetic signature of heavy metals pollution of sediments: case study from the East Lake in Wuhan,China

Detailed magnetic measurements and geochemical analyses were performed on 114 sediment samples collected from the East Lake, Wuhan city, China, to establish a possible link between the enhanced concentration of anthropogenic magnetic particles and heavy metals with known sources. Relatively higher magnetic susceptibility values (mass-specific, χ, >150 × 10⁻⁸ m³ kg⁻¹) were observed for samples near the pollution sources: e.g. the Wuhan Iron and Steel Company (WISC), the Qingshan Thermal Power Plant (QTPP), the banks (driveways) of the lake and near the sightseeing route of yachts on the lake. Moreover, χ is positively correlated to the concentration of Pb (correlation coefficient r = 0.682), but negatively or weakly correlated with both Zn and Cu. In contrast, anhysteretic remanent magnetization (ARM) is significantly correlated with these major heavy metals (r = 0.645 for Zn–ARM, 0.699 for Pb–ARM and 0.841 for Cu–ARM, respectively), which indicate that ARM serves a better indicator for the pollution of heavy metals in this lake. Thermomagnetic analysis combined with magnetic hysteresis measurements revealed that magnetites in the pseudo-single-domain/multidomain grain-size regions are dominant. Scanning electron microscopy and energy dispersive X-ray examinations of the magnetic extracts showed that these Fe-rich particles have different morphologies: orange-peel structure, hollow structure with adhered smaller particles, Zr-rich melted-like irregular particles, pear-shaped spherules and spherules with slick surfaces. These features are typical for particles produced by anthropogenic activities. Because of the genetic relationship between the environmental setting of the East Lake and the nearby pollution sources, this study suggests that in situ magnetic surveys are sensitive to evaluate the environmental pollution on the lake bottom.     

Deltas: the fertile dustbins of the continents

Deltas and their associated deep-water submarine fans are the main repositories of sediment produced by continental erosion. The internal structure of prograding deltas is often complicated by changes in loci of deposition and changes in land-sea levels during their formation. The high water content and rapid deposition cause syn-sedimentary deformation. Deltas have been inhabited by man throughout history due to their rich surface resources. Ancient deltas are rich in hydrocarbons which are widely exploited. They are very sensitive to changes in the hinterland and today their existence is threatened by anthropogenic actions such as dam construction and sea-level changes.     

Magnetic enhancement of urban roadside soils as a proxy of degree of pollution by traffic-related activities

Detailed magnetic and geochemical measurements were performed on urban roadside soils collected from Lishui city, China, to establish a possible link between the enhanced concentration of traffic-related magnetic particles and heavy metals. Relatively higher magnetic susceptibility (mean: 124.1 × 10⁻⁸ m³ kg⁻¹) and concentrations of metals (Cd, Cu, Pb and Zn) were observed for roadside soils. Concentration-dependent magnetic parameters (χ and SIRM) are highly significantly positively correlated to the concentration of metals (Ca, Cr, Ni, Cu, Zn, Cd, Pb, Fe, and V), but not significantly correlated with As, Mn, Co, Mg, and K. The principal component analysis showed that χ and SIRM significantly correspond to elements Ca, Cd, Cu, Pb, and Zn. The χ and SIRM also have significant linear correlation with integrated pollution index, indicating that χ and SIRM can be used as effective proxy indicators for the pollution of heavy metals. Magnetite in the pseudo-single-domain/multidomain (PSD/MD) grain size was identified as the dominant magnetic carrier by temperature-dependent measurements of saturation magnetization (Ms–T curve), XRD and hysteresis loops. Field emission scanning electron microscopy and energy dispersive X-ray spectroscopy (EDS) analysis of the magnetic particles revealed the presence of large traffic-related angular-subangular, blocky, and spherical iron oxide particles. These iron oxide particles are typical for particles produced by traffic-related anthropogenic activities. It is concluded that vehicle emissions may be the major source of elevated heavy metals and magnetic particles in roadside soils. The results proved the applicability of magnetic method in detecting roadside pollution derived from vehicle emissions.     

Anthropogenic organic matter in the Great Marsh of the Indiana Dunes National Lakeshore and its implications

Cores from the Great Marsh area of the Indiana Dunes National Lakeshore were examined in order to document variations in concentration, type and size of anthropogenic organic matter (A_nOM—coal, coke, etc.) and discuss their relationship to the concentration of such trace elements as Pb, Zn, and Mn in the near-surface sediment section. The results indicate that the first appearance of A_nOM corresponds to the onset of industrialization in the area. There is also a general relationship between the occurrence of A_nOM and Zn, Pb, and Mn. Trace metals were likely transported from the industrial sites to the area of their deposition as sulfur-bearing coatings on small anthropogenic particles. After deposition, these sulfur-bearing compounds reacted with organic matter within the marsh. As a result of bacterial reduction, the pyrite was produced, as suggested by a close relationship between the pyrite and A_nOM. Distance from the industrial complex upwind as well as local hydrologic conditions are among the major factors controlling distribution of A_nOM and trace elements. At the same distance from the source, types and sizes of A_nOM are influenced by the duration and frequency of flooding.     

Heavy metal pollution and soil magnetic susceptibility in urban soil of Beni Mellal City (Morocco)

The assessment of anthropogenic impact in the urban environment can be evaluated according to heavy metal contents of soils such as Pb, Cu, Zn, Cd and Fe. These elements have more affinity to establish metallic bond with ferrous material leading to enhancement of soil magnetic susceptibility. The objective of this study was to undertake joint magnetic and geochemical investigations of road-side urban soil materials to address the environmental pollution of Beni Mellal city that has been subjected to environmental stress, due to population overpressure and related urbanization. Twenty three soils magnetic susceptibility profiles were made along 5 km peripheral national road (N8) in Beni Mellal. The magnetic survey reported here for the first time on this City’s topsoils tries to establish the link between magnetic properties and the content of heavy metals. High magnetic susceptibility values and high contents of heavy metals were found near the paved edge of the road and within the place reserved as large engine park. Magnetic extracts of highly polluted areas and unpolluted soil (olive plantation) were analyzed by SEM coupled with RDX in order to discriminate anthropogenic magnetic spherules and pedo-lithogenic magnetite-like minerals. Magnetic mineralogy determined by Mössbauer spectroscopy suggests the presence of hematite, magnetite and goethite in highly polluted areas. The iron oxides and especially goethite are efficient in incorporating and/or adsorbing foreign ions.     

Anthropogenic gadolinium as a microcontaminant in tap water used as drinking water in urban areas and megacities

Gadolinium chelates have been used since 1988 as contrast agents in magnetic resonance imaging (MRI), and produce positive anthropogenic Gd anomalies in rare earth element (REE) patterns of river and lake waters. These Gd compounds are not removed in wastewater treatment plants (WWTP) due to their high stabilities, and are transferred to surface waters with the clearwater discharge from WWTP. Through natural and induced bank filtration, the anthropogenic Gd is also transported into groundwater. To date, there are no related acute health risks known, but the potential long-term effects of exposure to low doses have not been studied.Here REE data is presented for tap water from the City of Berlin, Germany, a metropolitan area that is known for its anthropogenic Gd-rich rivers and groundwater. Natural and induced bank filtration play important roles in Berlin’s freshwater resource management. Therefore, the extent to which municipal tap water that is used as drinking water is affected by anthropogenic Gd was investigated. Large positive Gd anomalies were found in tap water samples from the western districts of Berlin, indicating the presence of up to 18 ng/L of anthropogenic Gd on top of a geogenic background of 0.54 ng/L. In marked contrast, the amount of anthropogenic Gd in tap water from the eastern districts of Berlin is negligible to minor (maximum of 0.18 ng/L on top of a geogenic background of 0.26 ng/L). This strong regional difference likely results from the specific historical situation of Berlin, where before the re-unification of Germany in 1990, natural and induced bank filtration were necessities in isolated West Berlin, but unimportant in East Berlin, a situation that has seen little change during the past 20 years. Thus, drinking water resources in the western part of Berlin are more strongly affected by anthropogenic Gd than those in the eastern part. The high anthropogenic Gd concentrations found in some tap waters in Berlin clearly show that the Gd initially used as contrast agent is removed neither during natural nor artificial water treatment. This is further evidence for the high stability and long environmental half-lives of these compounds. Considering that the amount of anthropogenic Gd in the Havel River in Berlin has increased more than 4-fold over the past 15 years and that water migration from the Havel River to the groundwater wells take years to decades, the amounts of anthropogenic Gd in West Berlin tap water will increase further over the next few years. Due to its presence in tap water that is consumed as drinking water, millions of people are exposed to low doses of these anthropogenic Gd chelates. Additional data for the City of London, UK, for example, indicate that this is not a local phenomenon confined to the City of Berlin, but rather a common feature of tap water in metropolitan areas and megacities in countries with highly developed health care systems. Hence, the REE distribution in tap waters used for human consumption should be monitored, especially since the anthropogenic Gd chelates can also be used as tracers for emerging microcontaminants such as steroids, pharmaceuticals and personal care products.