Migration Of Trace Elements Research Articles

FEATURES OF TRANSPORT OF CERTAIN ELEMENTS IN WATER NORTH CASPIAN

Major influence on the form of migration of trace elements in the North Caspian has Volga runoff. The bulk of the elements in the Volga waters carried in the suspended solids. The exception is zinc, transports mainly in dissolved form. In article presents the results of a study of dissolved and suspended forms of zinc, copper, lead, and manganese in the surface water of the North Caspian Sea from 2002 to 2009. On the basis of the received data the ratio of dissolved and suspended forms of trace elements studied. According to calculations, the bulk of the copper, lead and manganese is carried in the suspended solids. Zinc migrates mainly in dissolved form. The dominant form of migration of the metal increases, depending on the season. For zinc, the migrant in the ionic state, and for copper, lead, manganese, transferring primarily in suspension, in the autumn period the increase in the proportion of dissolved (Zn) and suspended forms (Cu, Pb, Mn), respectively. Increase in the proportion of ionic forms of metals in the North Caspian occurred episodically in local areas. Over the entire study period the greatest number of excess dissolved form of weighted metal observed in the central part of the shallow zone predustevogo space p. Volga near the exit of the Kirov and Belinsky channels.

Effect of H2O and SO2 on the distribution characteristics of trace elements in particulate matter at high temperature under oxy-fuel combustion

The purpose of this work is to clarify the effects of high concentrations of H2O and SO2 on the generation of particulate matter (PM) and the distribution characteristics of trace elements in PM under oxy-fuel coal combustion. The experiments were carried out in a high temperature drop tube furnace which was set as 1500°C, and the Dekati Gravimetric Impactor (DGI) sampling system was applied to collect the PM at the outlet of the furnace (sampling temperature, 135°C). The results indicate that, compared to air combustion, oxy-fuel combustion significantly decreases the amount of PM and the total mass of trace elements in PM, but enhances the concentrations of trace elements in PM, except Mn. Under oxy-fuel combustion, similar conclusions about the formation of PM and migration of trace elements can be drawn, with the decreasing oxygen concentration. There is no significant difference in the amount of PM with the SO2 addition, but the total mass of trace elements or the concentrations of trace elements in PM decreases. Steam enhances the amount of PM and the total mass of trace elements in PM to a great extent but decreases the concentrations of trace elements in PM.

Geochemical processes controlling trace elemental mobility in coalbed natural gas (CBNG) disposal ponds in the Powder River Basin, WY

A concern with CBNG produced water disposal ponds is the potential migration of trace elements into the underlying shallow aquifers. Objectives of this research were to 1) examine the chemistry of CBNG produced water in outfalls and corresponding disposal ponds and 2) determine possible leaching of trace elements from the disposal pond sediments into shallow aquifers. The CBNG outfall water, disposal pond water, and sediment samples were collected from the Powder River Basin (PRB), WY during the summer months of 2006 to 2009. Water samples were analyzed for pH, major cations, anions, and trace elements. Geochemical analysis was performed using MINTEQA2 model to determine speciation, complexation, and mineral precipitation and dissolution processes to determine the mobility of trace elements in CBNG disposal ponds. Two types of SAR calculations were made: 1) practical SAR (SARp) was calculated based on Na+, Ca2+, and Mg2+ concentrations and 2) true SAR (SARt) was calculated based on MINTEQA2 calculated activity of Na+, Ca2+, and Mg2+. Sediment samples were analyzed for trace elements using toxicity characteristic leaching procedure (TCLP) to predict potential mobility of trace elements into the shallow aquifer. Research results suggest the pH of the CBNG produced water outfalls increases substantially in corresponding disposal ponds due to degassing of CO2 (carbon dioxide) from the disposal ponds. Observed high SAR values in CBNG disposal ponds compared to outfalls were attributed to increase in Na+ and decrease in Ca2+ concentrations. The decrease in Ca2+ concentration is attributed to the precipitation of calcite. Trace element concentrations such as As (arsenic), Cr (chromium), and Cu (copper) appear to increase in disposal ponds. Barium (Ba) and Mn (manganese) concentrations in the disposal ponds decreased substantially by precipitating as carbonate minerals into the sediments. Results of this study suggest that very minimum or no leaching of trace elements could occur from disposal pond sediments. However, further research is required to understand the role of SAR and sediment mineralogy in leaching of trace elements from CBNG disposal pond in the PRB, WY.

Trace metal distribution in pristine permafrost-affected soils of the Lena River delta and its hinterland, northern Siberia, Russia

Abstract. Soils are an important compartment of ecosystems and have the ability to buffer and immobilize substances of natural and anthropogenic origin to prevent their movement to other environment compartments. Predicted climatic changes together with other anthropogenic influences on Arctic terrestrial environments may affect biogeochemical processes enhancing leaching and migration of trace elements in permafrost-affected soils. This is especially important since Arctic ecosystems are considered to be highly sensitive to climatic changes as well as to chemical contamination. This study characterises background levels of trace metals in permafrost-affected soils of the Lena River delta and its hinterland in northern Siberia (73.5–69.5° N), representing a remote region far from evident anthropogenic trace metal sources. Investigations on the element content of iron (Fe), arsenic (As), manganese (Mn), zinc (Zn), nickel (Ni), copper (Cu), lead (Pb), cadmium (Cd), cobalt (Co), and mercury (Hg) in different soil types developed in different geological parent materials have been carried out. The highest median concentrations of Fe and Mn were observed in soils belonging to ice-rich permafrost sediments formed during the Pleistocene (ice-complex) while the highest median values of Ni, Pb and Zn were found in soils of both the ice-complex and the Holocene estuarine terrace of the Lena River delta region, as well as in the southernmost study unit of the hinterland area. Detailed observations of trace metal distribution on the micro scale showed that organic matter content, soil texture and iron-oxide contents influenced by cryogenic processes, temperature, and hydrological regimes are the most important factors determining the metal abundance in permafrost-affected soils. The observed range of trace element background concentrations was similar to trace metal levels reported for other pristine northern areas.

Role of global biological filters in geochemical migration of trace elements in the ocean: Comparative estimation

Role of global biological filters in geochemical migration of trace elements in the ocean: Comparative estimation

Migration of 18 trace elements from ceramic food contact material: Influence of pigment, pH, nature of acid and temperature

The effect of pH, nature of acid and temperature on trace element migration from ceramic ware treated with 18 commercially available glazes was studied. Besides of the well-studied lead and cadmium, migration of other toxic and non toxic elements such as aluminum, boron, barium, cobalt, chrome, copper, iron, lithium, magnesium, manganese, nickel, antimony, tin, strontium, titanium, vanadium, zinc and zirconium was investigated in order to evaluate their potential health hazards. Trace element concentrations were determined with Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). This study suggests that there is indeed a health risk concerning the possible migration of other elements than lead and cadmium. At low pH (2<pH<3), the nature of the acid plays an important role. Citric and malic acid seem to be more aggressive to the glaze than acetic acid except for aluminum, barium, chromium, iron and magnesium. The migration kinetics between pH 2 and 3 in acetic acid of these exceptions also are more exponential while the other elements display a decreasing linear gradient. In ceramics used for this study (fired at 900°C), a linear relationship between the migration and the temperature was observed.

Migration of Trace Elements in Fushun Oil Shale during Self-Combustion and its Environmental Significance

Self-combustion of oil shale has been occurring and widespread in a long term while oil shale was considerably piled in Fushun dumping sites. After collecting samples of high- and low-grade oil shale from Fushun West Open Mine, the self-combusted oil shale from Fushun West Dumping Site, and designing the indoor high-temperature incineration experiments to simulate the self- combustion process, we tested trace elements in them and their ashes of 700°C, 1000°C by means of ICP-MS. Based on the analysis and comparison of the test dada, we studied content characteristics and migration pattern of elements during self-combustion. The results showed that elements were distributed in the similar way in samples and contents of Zr, Sr, Cr, V, Zn, Ni, Rb and Li were very high. A large amounts of trace elements were found to enter the atmosphere through volatilization in the process of Self-combustion, especially those higher volatile elements, such as Sb, Zn, Pb, W, Sn, Ta and Cd, while a few elements preferred to concentrate in solid-phase ashes. Different distribution and migration capacities of elements might be the main reason for the higher concentration of some elements in self-combusted oil shale than their background values in Liaoning soil.

Estimation of the role of global biological filters in the geochemical migration of trace elements in the ocean: The marginal filter of the ocean

A quantitative estimate has been made for the contribution of biological processes to accumulation and transformation of the trace elements in the marginal biofilter of the ocean. It has been demonstrated that the proportion of phytoplankton having the largest biomass reaches 96–99% of the total mass of trace elements accumulated by biota. The mass of trace elements taken up by bivalved mollusks is tens to hundreds of times less than this, while that by macrophytes is an order of magnitude less than the latter. A dynamic parameter of the biogenic migration, namely the duration of the biological cycle of phytoplankton, has been calculated; this value does not exceed 2–3 days for Zn, Ni, Cu, Cd, Pb, Co, Fe, and Mn. First the trace metal balance in the whole body of mussels Mytilus spp. between the soft tissues and shells was calculated based on their weight proportion (0.1 and 0.9, correspondingly). As a result it was revealed that carbonate shells serve a great reservoir of Mn, Fe, Co, Ni, Cu and As and biomineralization is an important process in their bioaccumulation. The suggested new approach can be applied when making environmental and geochemical estimates of biotic self-purification of water bodies and when using shells as mineral supplements.

Results migration mobility investigation of microelements in the soil horizons under the influence of humus and carboxylic acids

Formation of regular soil profiles podzols of boreal zone is defined by extracting features of humic and carboxylic acids formed during the biodegradation of plant litter. The structure features of soil profiles associated with variable, but high rates of downward filtering of these aggressive acids in landscapes with seasonal humidity. We experimentally simulated these conditions for studying a wide range of mobility of trace elements in soil horizons [Alekhin and Kostyukova, 2002]. Experimental methodsreceptions at carrying out of these experiences were similar to what are used at chromatographic differentiation into columns with processing of results by a method of concentration curves [Alekhin and Lakshtanov, 2008; Lakshtanov and Alekhin, 2005]. Objects and methods. Soil and soil water samples were collected in Meshcherskaya lowland. Soil water was filtered through the filter with pore dimension of 0.2 micron. Four horizons of podzolic soil (humus (A), eluvial (E), illuvial ferruginous (Bf) and gley horizon transition from illuvial to the parent rock (BCg)) were used in experiment. Four columns which were tightly closed have been made of the selected material. At the first stage of the experiment through each column the distilled water was passed for research of migration of trace elements at its infiltration as analog of fresh meteoric precipitation through soil. Then through columns the distilled water with addition sodium azide (for suppression of ability to live of microorganisms of soils) was passed. The second stage of the experiment consisted in filtering through columns of the solution close on properties soil, with initially high content of humic and fulvic acids (with the addition of sodium azide). At the third stage in this solution, related soil, carboxylic acids: acetic, lemon and oxalic in a ratio 1: 0,05: 0,003 were added. Such concentration ratio of acids was chosen because it close to a natural ratio in water extracts from soils and acidity (pH = 4,2) the solution is comparable to natural size [Hees et.al., 1996]. Addition of these acids in filtrant allowed to make active process of migration of elements of soil layers, remaining within the limits of experiment approach to natural process. At the fourth stage of the experiment polyelement standard ICP-MS-68B Solution A (HighPurity Standards) was added to a solution with humic and carboxylic acids. The standard solution contains elements (Al, As, Ba, Be, Bi, B, Cd, Ca, Ce, Cs, Cr, Co, Cu, Dy, Er, Eu, Gd, Ga, Ho, In, Fe, La, Pb, Li, Lu, Mg, Mn, Nd, Ni, P, K, Pr, Re, Rb, Sm, Sc, Se, Na, Sr, Tb, Tl, Th, Tm, U, V, Yb, Y, Zn) with concentration 100,0 ± 0,5 mg/l. The standard was dissolved so that initial concentrations of all elements in a solution were 1 mg/l (pH = 3,5). Addition of microelements given the chance to study method of adsorption curves of elements by columnar material (soil), and also to compare concentration of trace elements in filtrates. Filtrates were selected time a day during all experiment. In parallel with sampling potentiometry (pH, pNa, pCa) for control of change of indicators were spent. Each following stage began after an establishment in system of stable indicators. The mass spectrometer of the high permission with is inductive-connected plasma ELEMENT of 2 Thermo Finnigan was applied to definition of concentration of trace elements in filtrates.

流体包裹体研究：进展、地质应用及展望

Fluids are aubiquitous transport medium for heat and matter in most geological process.The presence of fluids in rocks may affect the chemical and physical properties,mineral reaction velocity and heat budget of geological systems,Direct sample of geological fluids could be preserved only in fluid inclusions that were trapped during the growth of their host mineral.Fluid inclusions can provide us unique information for the presence and composition of ancient fluids which can not be obtained by other geochemical methods(e.g.the component and evolution of diagenetic fluid;process of fluid-rock interaction;migration of trace elements in fluid).The study of fluid inclusions thus has become one of the hottest fields in earth sciences,and plays an important role in studies correlated with geological processes.Starting with a general introduction to the fluid inclusion properties and a summarization about the classification of primary-and secondary-fluid inclusions,this paper reveiws the most recent development in analytical methods in the fluid inclusion research field.We also review the current application of fluid inclusions to various fields in earth sciences(e.g.metamorphic fluid,ore-deposit,petroleum geology and biomarker) in the paper.Finally,we give a short outlook on potential future research topics about fluid inclusion studies.

The Distribution of Metals in Soils and Pore Water at Three U.S. Military Training Facilities

Small arms firing ranges at military training facilities can have enormous heavy metal burdens (percent level) in soils. Currently there are few published works that quantify the metal content of soils and waters at military installations or speculate on the potential for migration of these contaminants into groundwater. This article documents metals in soils and waters at nine small arms training ranges at three military installations in the U.S. Soil samples were collected from the surface and shallow subsurface. The results demonstrated that lead, antimony, copper, and zinc were the principal contaminants of interest and mapping a site's lead and copper surface distributions would adequately define the extent of impacted soil. Lower metal concentrations at three of the ranges reflected previous remediation by means of physical separation and mechanical removal of metallic fragments followed by fixation treatment with MaectiteTM. Except for the treated ranges where mixing had occurred, subsurface soil samples indicated limited vertical migration. Several of the ranges were also monitored for trace element migration in the vadose zone by means of suction-cup lysimeters. This pore-water sampling indicated ceramic suction-cup lysimeters are useful for assessing relative concentrations but require care in evaluation because of potential sorption losses. Monitoring of soil water at ranges should include antimony and zinc; the former because, in contrast to the other metals, it is typically soluble in an anionic form, and the latter because of its greater solubility and mobility.

Migration and enrichment of trace elements of Lower Palaeozoic carbonate rock strata in Beijing

Analyses of trace elements of the Lower Palaeozoic carbonate rock strata in Beijing show that the contents of As, Hg, F increase from primary carbonate rocks to weathered carbonate rocks and from primary carbonate rocks to the soil coexisting with carbonate rocks, but the distribution regularity of S is not obvious. In the whole weathered stages, the sorption of As is mainly affected by Fe2O3. In soil Fe2O3 is also the main affecting factor of Hg enrichment. The main existing forms of Hg in primary carbonate rocks should simply be physical adsorption, coprecipitation and false isomorphous form between surface of carbonate rock and Hg. In soil the enrichment of F has little relationship with sulfides and Fe2O3. In primary carbonate rocks, F is mainly absorbed by sulfides and clay minerals, etc. Weathered samples have closer genetic relationships with primary carbonate rocks. This also implies that weathered carbonate rocks have the close existing forms to that of primary carbonate rocks. In primary carbonate rocks FeS2 and FeS are the main forms of S, and sulfides have fixation effect on some heavy metals, whereas in weathered carbonate rocks and soil the fixation effect is weakened.

Selective detection of Fe and Mn species at mineral surfaces in weathered granite by conversion electron yield X-ray absorption fine structure

A new method for the speciation of Fe and Mn at mineral surfaces is proposed using X-ray absorption fine structure in conversion electron yield mode (CEY-XAFS). This method generally reflects information on the species at the sub-μm scale from the particle surface due to the limited escape depth of the inelastic Auger electron. The surface sensitivity of this method was assessed by experiments on two samples of granite showing different degrees of weathering. The XANES spectra of the Fe-K and Mn-K edge clearly gave different information for CEY and fluorescence (FL) modes. These XANES spectra of Fe and Mn show a good fit upon application of least-squares fitting using ferrihydrite/MnO2 and biotite as the end members. The XANES spectra collected by CEY mode provided more selective information on the secondary phases which are probably present at the mineral surfaces. In particular, CEY-XANES spectra of Mn indicated the presence of Mn oxide in unweathered granite despite a very small contribution of Mn oxide being indicated by FL-XANES and selective chemical-extraction analyses. Manganese oxide could not be detected by micro-beam XANES (beam size: 5 × 5 μm2) in unweathered granite, suggesting that Mn oxide thinly and ubiquitously coats mineral surface at a sub-μm scale. This information is important, since Mn oxide can be the host for various trace elements. CEY-XAFS can prove to be a powerful tool as a highly sensitive surface speciation method. Combination of CEY and FL-XAFS will help identify minor phases that form at mineral surfaces, but identification of Fe and Mn oxides at mineral surfaces is critical to understand the migration of trace elements in water-rock interaction.

Fate of trace elements during alteration of uraninite in a hydrothermal vein-type U-deposit from Marshall Pass, Colorado, USA

Alteration of uraninite from a hydrothermal vein-type U-deposit in Marshall Pass, Colorado, has been examined by electron microprobe analysis in order to investigate the release and migration of trace elements W, As, Mo, Zr, Pb, Ba, Ce, Y, Ca, Ti, P, Th, Fe, Si, Al, during alteration, under both reducing and oxidizing conditions. The release of trace elements from uraninite is used to establish constraints on the release of fission product elements from the UO 2 in spent nuclear fuels. Uraninite occurs with two different textures: (1) colloform uraninite and (2) fine-grained uraninite. The colloform uraninite contains 1.04–1.75 wt% of WO 3, 0.16–1.70 wt% of As 2O 3, 0.06–0.88 wt% of MoO 3; whereas, the fine-grained uraninite retains 2.25–4.93 wt% of WO 3, up to 5.76 wt% of MoO 3, and 0.26–0.60 wt% of As 2O 3. The near constant concentration of incompatible W in the colloform uraninite suggests W-incorporation into the uraninite structure or homogeneous distribution of W-rich nano-domains. Incorporation of W and Mo into the uraninite and subsequent precipitation of uranyl phases bearing these elements are critically important to understanding the release and migration of Cs during the corrosion of spent nuclear fuel, as there is a strong affinity of Cs with W and Mo. Zoning in the colloform texture is attributed to variation in the amount of impurities in uraninite. For unaltered zones, the calculated amount of oxygen ranges from 2.08 to 2.32 [apfu, (atom per formula unit)] and defines the stoichiometry as UO 2+ x and U 4O 9; whereas, for the altered zones of the colloform texture, the oxygen content is 2.37–2.48 [apfu], which is probably due to the inclusion of secondary uranyl phases, mainly schoepite. The supergene alteration resulted in precipitation of secondary uranyl minerals at the expense of uraninite. Four stages of colloform uraninite alteration are proposed: (i) formation of an oxidized layer at the rim, (ii) corrosion of the oxidized layer, (iii) precipitation of U 6+-phases with well-defined cleavage, and (iv) fracture of the uraninite surface along the cleavage planes of the U 6+-phases.

Numerical simulation of trace element transport on subsurface environment pollution in coal mine spoil

An understanding of the dynamic behavior of trace elements leaching from coal mine spoil is important in predicting the groundwater quality. The relationship between trace element concentrations and leaching times, pH values of the media is studied. Column leaching tests conducted in the laboratory showed that there was a close correlation between pH value and trace element concentrations. The longer the leaching time, the higher the trace element concentrations. Different trace elements are differently affected by pH values of leaching media. A numerical model for water flow and trace element transport has been developed based on analyzing the characteristics of migration and transformation of trace elements leached from coal mine spoil. Solutions to the coupled model are accomplished by Eulerian–Lagrangian localized adjoint method. Numerical simulation shows that rainfall intensity determined maximum leaching depth. As rainfall intensity is 3.6 ml/s, the outflow concentrations indicate a breakthrough of trace elements beyond the column base, with peak concentration at 90 cm depth. And the subsurface pollution range has a trend of increase with time. The model simulations are compared to experimental results of trace element concentrations, with reasonable agreement between them. The analysis and modeling of trace elements suggested that the infiltration of rainwater through the mine spoil might lead to potential groundwater pollution. It provides theoretical evidence for quantitative assessment soil-water quality of trace element transport on environment pollution.

Occurrence and migration of hazardous trace elements in coals from Guizhou Province, China

Occurrence and migration of hazardous trace elements in coals from Guizhou Province, China

04/00918 Study on the influencing factors of migration of trace elements in a pulverized coal-fired boiler: Huang, Y. et al. Reneng Dongli Gongcheng, 2003, 18, (1), 30–34. (In Chinese)

By using a Z-8200 atomic absorption spectrophotometer and a VF-320 X-ray fluorescent spectrograph the content of nine trace elements in raw coal, bottom slag and fly ash was measured quantitatively in a 220 th pulverized coal-fired boiler. On the basis of an improved relative enrichment factor of Meij and from the perspective of two aspects, namely, bottom slag and fly ash, a systematic analysis was performed of the influence of various factors on the law of migration. Such factors include: temperature, oxygen content, fly ash diameter, the properties of trace elements per se and the characteristics of coal rank. The results of the analysis indicate that an rise in furnace temperature can quicken the volatilization of some of the trace elements. The content of Cr and Mn in fly ash and bottom slag is comparable, but the two elements differ markedly in respect of relative enrichment factor. Low oxygen content does not always promote the volatilization of all trace elements. The content of Pb, Cd, Zn and Cr in the bottom slag and fly ash does not assume a linear relationship with their respective boiling points. The smaller the diameter of the fly ash, the greater the enrichment factor of the trace elements. The tendency of variation of various trace elements with the decrease in fly ash diameter has been found to be not identical for different trace elements.

Accumulation and Migration of Trace Elements along Trophic Chains in Ecosystems of the Chatkal Biosphere Reserve (the Western Tien Shan, Uzbekistan)

Concerning the involvement of living matter into the global matter and energy flows in the biosphere, migration of substances along trophic chains in natural ecosystems is a factor of greatest functional significance. As the internal structure of ecosystems is based on stable trophic connections through the matter and energy flows, the pattern of migration and accumulation of substances in the trophic links of ecosystems may serve as an indicator of ecosystem stability (Krivolutskii and Pokarzhevskii, 1990). In other words, the constancy of the rate of matter and energy flow and accumulation in the trophic chains of an ecosystem characterizes its state as stable. This primarily concerns the ecosystems of background areas. In this context, it appears important to perform comparative studies on the migration and accumulation of substances in the trophic chains of natural ecosystems unaffected by the anthropogenic impact. The main purpose is to reveal both the general pattern of these processes on the biospheric scale and specific regional or local features of the input and accumulation of certain substances and elements in the trophic links of individual ecosystems.

Migration of trace elements from pyrite tailings in carbonate soils.

In the carbonate soils contaminated by a toxic spill from a pyrite mine (Aznalcóllar, southern Spain), a study was made of a thin layer (thickness = 4 mm) of polluted soil located between the pyrite tailings and the underlying soil. This layer, reddish-yellow in color due to a high Fe content, formed when sulfates (from the oxidation of sulfides) infiltrated the soil, causing acidification (to pH 5.6 as opposed to 8.0 of unaffected soil) and pollution (in Zn, Cu, As, Pb, Co, Cd, Sb, Bi, Tl, and In). The less mobile elements (As, Bi, In, Pb, Sb, and Tl) concentrated in the uppermost part of the reddish-yellow layer, with concentration decreasing downward. The more mobile elements (Co, Cd, Zn, and Cu) tended to precipitate where the pH was basic, toward the bottom of the layer or in the upper part of the underlying soil. The greatest accumulations occurred within the first 6 mm in overall soil depth, and were negligible below 15 mm. In addition, the acidity of the solution from the tailings degraded the minerals of the clay fraction of the soils, both the phyllosilicates as well as the carbonates. Also, within the reddish-yellow layer, gypsum formed autigenically, together with complex salts of sulfates of Fe, Al, Zn, Ca, and Mn, jarosite, and oxihydroxides of Fe.

Application of Multitracer Technique to the Studies on Migration of Trace Elements in Geosphere

Application of Multitracer Technique to the Studies on Migration of Trace Elements in Geosphere