A field filtration method for the concentration and separation of suspended particulate matter (SPM) from freshwater systems and the subsequent determination of major, minor, trace and ultra trace elements (Al, As, Ba, Be, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, Hf, K, Mg, Mn, Mo, Na, Nb, Ni, P, Pb, Rb, S, Sb, Sc, Si, Sn, Sr, Ta, Th, Ti, Tl, U, V, W, Zn and Zr) is validated with respect to detection limits, precision, and bias. The validation comprises the whole procedure including filtration, sample digestion and instrumental analysis. The method includes two digestion procedures (microwave acid digestion and alkali fusion) in combination with inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma quadrupole mass spectrometry (ICP-QMS). Total concentrations of these 38 trace and major elements have been determined in suspended particulate matter (SPM) from lake and river water with low levels of suspended solids (<2 mg l-1 DW), and a wide range of element concentrations. The precision of the method including filtration, digestion and instrumental determination ranges between 8 and 18% RSD for most elements on a dry weight basis. Higher recovery after acid digestion is found for some elements, probably because of volatilization or retention losses in the fusion procedure. Other elements show higher recovery after fusion, which is explained by more efficient decomposition of mineral phases relative to the non-total acid digestion. Non-detectable concentrations of some elements are reported due to small differences between blank filter levels and the amounts of elements present on the filters after sampling. The calculated sums of main inorganic components, expressed as oxides, ranges between 94.0 and 98.0% ash weight. The method limits of detection range between 0.7 ng and 100 µg, as estimated from the blank filter samples. These detection limits are 3-1000 times higher compared to the corresponding instrumental limits of detection. The accuracy and bias of the overall analytical procedure was assessed from replicate analysis of certified reference materials. A better knowledge of the mechanisms of filter clogging in sampling of suspended matter is important in order to extend the applicability of the method. For the sample types investigated in this study, the amount of inorganic material in the suspended particulate matter (SPM) seems to be the most important factor controlling the maximum volume of filterable water, and Fe is presumable the most important clogging regulating parameter in the group of elements included in the inorganic matter. A critical evaluation of the instrumental capabilities of the ICP- QMS instrumentation in comparison with the sensitive double focusing sector field plasma mass spectrometry technique (ICP-SFMS) is also included. It was found that a modified microwave acid digestion procedure in combination with ICP-SFMS could replace ICP-AES determinations and fusion digestions for most of the investigated elements. Guidelines and limitations for this powerful and relatively simple and less time consuming procedure, covering most elements in one single determination, are discussed. / Godkänd; 2004; 20070126 (ysko)

The Aitik mine, near Gällivare in Sweden, is the largest copper mine in Europe with an annual production exceeding 18 Mt of ore. After processing of the ore the residual waste material, so called tailings, are deposited in a tailings pond. In addition, 15 - 25 Mt of barren waste rock is mined annually in order to provide access to the ore. The waste rock is deposited in waste rock dumps located close to the mine. The production started 1968, and very large quantities of waste have been accumulated since. A comprehensive set of strategies for management and decommissioning of the waste deposits have been developed, based on studies, investigations and tests carried out by Boliden, as well as independent consultants and universities, since the first permit regulating reclamation issues came into force 1989. During operation of the mine, the emissions to the receiving environment are limited. During a normal year, the effluent contains less than 50 kg of copper. However the internal circulation of copper is orders of magnitude larger. This fact calls for suitable decommissioning measures to prevent an increase of the emissions after closure. Moreover, by developing and implementing strict waste management routines the potential environmental impacts can be minimized and closure costs drastically reduced. As a foundation for the test work a variety of site investigations were carried out to establish the hydrogeological and geochemical conditions. Material characterization results show that some but not all waste types and categories may cause acid rock drainage (ARD). In order to reach conclusive results extensive kinetic test periods, using column and humidity cell tests, were required in combination with geochemical modelling to provide reliable results. Results of long term weathering and leaching tests on mill tailings were compared with measured weathering rates in field. The results show that weathering in field is much slower than in lab, but that there is still a potential for generation of acid leachate in the upper section of the tailings storage facility after closure. An alternative strategy was therefore developed, in which the iron sulphides will be removed from the bulk volume of the tailings during the last years of operation. The tailings depleted of sulphides would hence constitute a cover on the underlying tailings, with water saturation of the untreated tailings with higher sulphide content. The enriched sulphide product needs to be deposited separately during the last years and decommissioned using other methods, e.g. engineered cover or water cover. This can be obtained either in a selected part of the existing tailings pond where water saturation can be guaranteed, or by depositing the high sulphide tailings in the bottom of the open pit which will fill up with water after closure. Various reclamation methods for the waste rock deposits have been evaluated. Tests show that only a fraction of the tonnage is reactive, in average 20% without taking into account mixing due to practical reasons, which will increase the tonnage of contaminated rock. Therefore, procedures for selective management and deposition have been introduced for each rock type present. Existing dumps of mixed rock, when completed, will be covered with 2*0,5 m of compacted till and a topsoil of till with a content of sewage sludge or similar additive as vegetation layer. The oxygen inflow is thereby limited to 1% of the case before covering. Old dumps containing marginal ore, which were found to be the main sources of metals at the site, have been removed and processed and hence eliminated as sources of contaminant release. Large quantities of non-reactive waste rock are managed in a separate mass flow, constituting a large future source for aggregates production for construction purpose. The Aitik decommissioning project constitutes an example of how scientific methods applied to real life problems can lead to reduced potential environmental impacts, reduced liabilities, reduced closure costs as well as improved resources use - all in line with the sustainable development philosophy. / Godkänd; 2005; 20061214 (haneit)

Investigations concerning naturally occurring, mass dependent isotope fractionation of transition elements in biological materials have only been carried out during a very short period of time. Due to the lack of detailed descriptions of the analytical performance in previously reported work, the major focus of this study has therefore been to evaluate aspects of sample preparation and detection for obtaining precise and accurate isotopic ratios by multi-collector inductively coupled plasma mass spectrometry (MC- ICP-MS) using high mass-resolution. Quantitative determinations of elemental concentrations were performed by sector field ICP-MS using external calibration and internal standardization. Dissolution of whole blood and soft tissue reference materials in a micro-wave oven, or on a hot plate, using HNO3 resulted in concentrations of Zn, Fe and a host of other elements in agreement with certified values. This, together with high chemical yields of Zn and Fe (>93%) from the sample purification by anion- exchange chromatography or precipitation by NH3, limited the possibility for laboratory-induced isotope fractionation. Concentrations of the majority of potentially interfering elements were reduced to negligible levels, and most of the residual spectral interferences were resolved using medium (in the case of Zn) or high (Fe) mass-resolution settings of the MC-ICP-MS-instrument. To correct for differences in instrumental mass discrimination effects between samples and isotopic standards, concentrations were matched to within 10-20%, and Cu and Ni were employed as elemental spikes, for measurements of Zn and Fe, respectively. Almost all samples and standards were analysed in duplicate (or triplicate), and exponential correction for instrumental mass discrimination was performed by applying the exponential model. Precision at the sub-‰ level was achieved for both Zn and Fe delta-values, relative to a JMC Zn standard and an IRMM-014 Fe isotopic reference material, respectively. For the investigated reference materials, delta66/64Zn ranged from 0.07 ± 0.03‰ in human hair to 0.50 ± 0.03‰ in bovine muscle. Concerning Fe, a delta56/54Fe-value of -2.83 ± 0.06‰ was obtained for a human whole blood reference material. Variations in delta66/64Zn values, ranging from +0.56‰ in human whole blood to -0.60‰ in human hair were found, demonstrating fractionation of the Zn pool between body compartments. Where comparable isotopic determinations exist, the results were in good agreement. / Godkänd; 2004; 20070127 (ysko)

<p>Godkänd; 1998; 20070404 (ysko)</p>

Two abandoned pit lakes in northern Sweden were studied in order to improve the understanding of the geochemistry of pit lakes, Rävlidmyran Pit Lake and Udden Pit Lake. Both lakes show strong similarity with other mining lakes in terms of low pH and high metal and sulphate contents. Still, the two lakes have distinctly limnological and geochemical characteristics. Rävlidmyran Pit Lake is oligotrophic and meromictic. The lake is permanently stratified and three layers, the mixolimnion at the top, the chemocline below and the monimolimnion further below, are identifiable. Groundwater filling and stratification strongly control the elemental distributions in the lake. Most elements such as Ca, Mg, Na, K, S, Mn, Fe and Zn have lowest and constant concentration in the mixolimnion. Concentrations increase in the chemocline and keep rising in the monimolimnion. These elements show quite similar behaviour in the water with strong correlations. Groundwater is supposed to be the major source. Fe is removed from the mixolimnion due to oxidation and precipitation, but it is redissolved in the monimolimnion. Udden Pit Lake is a dimictic lake. Distinct overturning in spring and autumn occurs in the lake, during which the whole lake circulates and most of the parameters and chemical components become homogeneously distributed. The lake is thermally stratified in summer and winter. Three layers, the epilimnion at the top, the metalimnion below and the hypolimnion at depth could be identified. The thermal strata do not control the elemental distribution. During stratification, the concentrations of dissolved elements appear to be constant at most depths. Variations mainly occur in the top and bottom waters. Most elements such as Ca, Mg, Na, K, S, Mn, Cu Al and Zn have lowest concentration in the epilimnion. Concentrations increase in the metalimnion and kept constant in the hypolimnion. Fe concentration distribution reflects the changes of redox potential. High amounts of Fe2+ reaching the surface water by drainage waters from closely situated waste rock dumps cause higher dissolved Fe concentration and lower redox potential in the top water. Precipitation of dissolved Fe into suspended Fe occurs in deeper water where the redox potential is higher. In both lakes, a strong relationship between Cu and Al is found. Gibbsite is important since it controls both dissolved Al and Cu concentrations in the lake through processes of adsorption and precipitation. Otherwise scavenging processes by particles are not a significant factor controlling trace metal distributions due to the low suspended particle concentration in both lakes. Sulphate reduction was neither observed in Rävlidmyran nor in Udden, even though the oxygen concentration is poor in the deep waters. The high redox potential limits the formation of sulphides, thus precluding an important precipitation of trace metals as metal sulphides. / Godkänd; 2002; 20070222 (ysko)

A 50 meter thick unit of Proterozoic cumulate layered wehrlite, lherzolite, and olivine websterite exposed at river mile 91 in the Ninetyone Mile Creek Canyon, a side canyon to the Grand Canyon, Arizona, USA, hosts numerous spheroid to ellipsoidal, dunite enclaves that range in size from 1 to 20 cm in diameter. Major-element geochemical analyses suggest that the dunite enclaves and cumulate peridotites are co-genetic. A harzburgite enclave does not appear to be related by fractionation to either the surrounding cumulate peridotite or the dunite enclaves. The unusual major element composition of the harzburgite enclave is also not a product of reaction with a percolating melt. It is suggested that the harzburgite enclave formed as a residue of partial melting of a less primitive peridotite. The ellipsoid and tear-drop shapes of many of the enclaves suggests that they were emplaced while hot enough for ductile deformation. Diffusion profiles also suggest emplacement while both the enclaves and the surrounding cumulate peridotite were still at high enough temperatures for rapid diffusion. The restitic harzburgite enclave(s) were probably dislodged from their original location by eruptive events, tectonic events, or convective flow followed by gravitational settling and deposition before being subsequently covered by more evolved cumulate peridotite. The dunite enclaves were either dislodged and transported in a similar fashion or moved, transported, and ultimately deposited by a within-pluton mass wasting event before being covered by more evolved cumulate peridotite. Chromite, hercynite, and magnetite grains included in olivine, serpentinized olivine, and pyroxene from the Ninetyone Mile Peridotite. With the exception of a single sample, spinel grains observed in the Ninetyone Mile Peridotite retain very little of their original igneous composition. Subsequent overprinting by post-cumulus, subsolidus, and metamorphic processes dominates the eventual compositions providing some insights into the evolution of the Ninetyone Mile Peridotite. Interaction between spinel grains and trapped intercumulus melt (or liquid) during the later stages of crystallization resulted in a slight increase in Cr/[Cr+Al] and large increases in Fe3+/[Fe 3++Cr3++Al3+] and TiO2. The extent of these changes suggests a large shift in melt composition and a long of time between the crystallization of earlier mineral phases and the remainder of the melt in the Ninetyone Mile Peridotite magma chamber. Sub-solidus re-equilibration of Mg and Fe between spinel grains and surrounding olivine resulted in a substantial decrease in Mg/[Mg+Fe2+] in spinel. Subsolvus unmixing textures (hercynite + magnetite) in some of the better-preserved grains, and re-equilibration of Fe3+ between spinel grains and surrounding clinopyroxene and serpentine suggest slow cooling as well. Hydrothermal metamorphism led to decreases in spinel TiO2 and increases in Cr/[Cr+Al]. Amphibole occurring in both inclusions with spinel and silicate grains in olivine formed as devitrified hydrous melt inclusions. In the most evolved lherzolite samples in the Ninetyone Mile Peridotite, coronas of orthopyroxene and orthopyroxene + amphibole symplectite are ubiquitous in separating cumulate grains of olivine from interstitial amphibole (with minor amounts of magnetite, spinel, and clinopyroxene), and occasional, albitic plagioclase. Compositional (low-Al coronitic orthopyroxene and albitic plagioclase) and textural (cuspate, convex inward olivine-orthopyroxene grain boundaries) evidence suggests that the olivine corona microstructures in the Ninetyone Mile Peridotite formed during a multistage process involving reaction between cumulate olivine and surrounding interstitial volatile-rich liquid. SiO 2 in the liquid reacted with olivine resulting in the inward dissolution of olivine to form orthopyroxene. Simultaneously, O2 from the liquid oxidized the fayalite component in the olivine, producing magnetite and SiO 2. The fayalite consumption resulted in a wide layer (reaction rim) of low-Al orthopyroxene with higher Mg/(Mg+FeTotal) than the original olivine and the production of small amounts of magnetite near the new orthopyroxene grain boundary. A change in the composition of the liquid then resulted in the partial replacement of orthopyroxene by amphibole and the formation of an orthopyroxene + amphibole symplectite layer. Finally, highly fractionated interstitial liquid crystallized to form albitic plagioclase. The availability of H2O was an important factor in the development of these coronas. The reactions depicted in the coronas in the Ninetyone Mile Peridotite occurred at pressures greater than 0.6 GPa and at ∼900-1000°C, which is consistent with regional metamorphic history.

Plagioclase phyric lavas of the Roza Member cover approximately 40,000 km$\sp2$ in Oregon and Washington. Field relationships in 85 stratigraphic sections and geochemical analysis of 765 samples indicate that the Roza Member consists of 1 to 4 flow units. Systematic variations in Cr, Nb, Zr, P$\sb2$O$\sb5$, and TiO$\sb2$ allow these flow units to be divided into 6 chemically distinct subtypes. Incompatible element abundances decrease while the Cr concentration and plagioclase phenocryst population increase upward through the Roza succession. Most other elements display only minor variations. Stratigraphic relations between the 6 Roza subtypes are complex. The areal distribution of each subtype reflects the interaction of the constructional topography of older Columbia River basalts, regional structure, geomorphology, and location and timing of activity along the 175-km long linear Roza vent system. The distribution of the chemically defined subtypes within the dikes and vents indicate that only short segments of the vent system were active at any given time. Calculations (assuming a conductive cooling regime--an assumption supported by primary intraflow features and cooling-joint measurements), indicate that decades elapsed between successive Roza eruptions. These temporal constraints are supported by a lack of saprolite horizons between Roza cooling units and an absence of large-scale geochemical variation due to magma reservoir processes, and are consistent with estimates of Columbia River basalt recharge rates. The earliest Wanapum eruptions (the Robinette Mountain and Dodge Basalts, Eckler Mountain Member) were distinctly more mafic than the subsequent "main" Wanapum Frenchman Springs-Roza-Priest Rapids sequence (e.g., Rob. Mtn.: Mg' $\approx$ 61, Nb $\approx$ 4ppm, Cr $\approx$ 137ppm; versus Roza: Mg' $\approx$ 39, Nb $\approx$ 15ppm, Cr $\approx$ 33ppm). The main Wanapum succession is enriched in both the large ion lithophile elements (K, Rb, Ba, Th) and radiogenic isotopes relative to the Eckler Mountain lavas. However, similar incompatible element rations for the Wanapum basalts imply lava derivation from comparable mantle sources. Major and trace element modelling suggest that coupling fractional crystallization of OL + PL + CPX + TiMT ($\approx$5:60:34:1) with periodic eruption of $\approx$10 volume percent of a steady state reservoir, minor ($\approx$3%) assimilation of crust similar to the Wallowa Batholith, and recharge by a Robinette Mountain-like parental magma can generate lavas compositionally similar to the Frenchman Springs-Roza-Priest Rapids sequence.

Samples of Hawaiian tholeiitic basalt were collected from successive prehistoric flow and intrusive units, exposed on the walls of the summit caldera of Mauna Loa Volcano. Based on major, minor, and trace element analyses, a caldera stratigraphy divided into three separate lava suites is presented. Suite A, the oldest, consists of sparsely to moderately phyric lavas with generally low levels of MgO (6.6 $\pm$ 0.5%) and highly variable incompatible element ratios (K/Y 136 $\pm$ 16) that systematically decrease with time. Suite B is characterized by moderately to highly phyric lavas with highly variable major element chemistry (10.9 $\pm$ 3.2% MgO), predominantly controlled by the addition or subtraction of olivine. Incompatible element ratios are generally low (K/Y 129 $\pm$ 7) and progressively increase with time. The youngest Suite (C) consists of sparsely phyric lavas with low levels of MgO (6.6 $\pm$ 0.2%) and uniformly high levels of incompatible elements (K/Y 158 $\pm$ 5). A tentative correlation with radiocarbon dated flank eruptives constrain the age of the oldest examined lavas to approximately 1,500 yrs, and the youngest to roughly 590 yrs. Sill-like intrusive units were found to be compositionally indistinguishable from Suite B lavas, and probably the result of downward or lateral injection of dense, ponded Suite B lava. Correlations between incompatible element ratios, major element compositions, and flow morphologies indicate that Mauna Loan lava chemistry is linked with eruptive activity and magma supply rate. Periods of high magma supply rates are associated with MgO-rich, incompatible element depleted lavas, whereas infrequent, low-volume activity is linked with moderately evolved, incompatible element enriched eruptives. The observed systematic oscillation of incompatible element ratios with time is consistent with the view that the range of incompatible element abundances observed in Mauna Loan lavas has not significantly change over the last 30,000 years (Rhodes et al., 1982). A change in eruptive behavior probably occurs each time there is a significant shift in incompatible element ratios. This behavioral scenario is consistent with the open-system, shallow (3-5 km depth) magma reservoir model of Rhodes (1987; 1988).

The manufacture, transport, use and disposal of organic chemicals may result in the release of significant quantities of organic substances into soil, from which they are subject to possible transport into underlying groundwater. Many of these organic chemicals are potentially toxic (Wilson et al., 1981). Information is required concerning the chemical and physical behaviour of organic chemicals in the soil environment in order to implement measures that will protect groundwater but also permit reasonable usage of soil for waste containment. This study deals with the interactions of a smectitic clay soil of the Rensburg form and two petrochemical wastes, which were sampled from storage dams, adjacent to a petrochemical plant at Secunda, South Africa. There is growing interest at the plant in utilizing soil for cost-effective waste containment and treatment. The objectives of this study were twofold: firstly, to determine the permeability of the Rensburg soil with respect to the two waste liquids (BPlO- aqueous and phenolic, and BP2- non-aqueous); and, secondly, to investigate the sorptive capacity of the clay fraction of the soil for two common groundwater contaminants, benzene and phenol, in the context of the potential for using treated clays for decontaminating BP10 and other organic wastes. The Rensburg soil was compared with a commercial bentonite for containing and treating petrochemical waste.

Godkänd; 1999; 20070403 (ysko)