Oxidation of sulfidic mine waste is of significant environmental concern due to the consequent formation of acid rock drainage (ARD), deteriorating the water quality of natural water systems. Iron (Fe) and sulfur (S) are two major redox elements involved in these reactions and typically the major redox-sensitive elements (whose solubility, speciation, and mobility are affected by pH and Eh) in water affected by ARD. Measurements of Fe and S species concentrations may reveal valuable information about geochemical processes in mine waste but are typically included when analyzing the chemical composition of ARD. In this study, robust and portable methods for the determination of Fe and S species concentrations in leachate water affected by sulfidic mine waste were tested and evaluated. The leachate water resulting from interaction with high-  and low-sulfide waste rock was collected from three leaching columns, each reflecting different geochemical environments that could occur during mine waste management: (1) fully oxidized conditions (reference column), (2) gradual oxygen depletion from atmospheric level to <1% (anoxic column), (3) treatment with alkaline industrial residual material (alkaline column). The leachate water was analyzed for its pH, Eh, electric conductivity (EC), and major and trace elements. UV-Vis spectrophotometric ferrozine method was tested and applied for Fe speciation and concentration analysis, allowing determination of Fe(II) and Fetot and further calculation of Fe(III) as a difference. The method was found to achieve accurate and reliable results. Turbidimetry was tested and evaluated for dissolved sulfate analysis, and even though the analytical precision was poorer, ca. ±20%, the method provides useful semi-quantitative estimations of dissolved sulfate concentrations. Both spectrophotometry and turbidimetry are easy to perform and utilizes robust, cheap and portable instrumentation. Leachate water from the high and low sulfide experiments had pH and Eh in the range of pH 2.6 – 12 and Eh 200 – 720 mV and pH 3.5 – 4 and Eh 550 – 700 mV, respectively. Measurements of iron species and sulfate concentrations revealed that sulfate was the dominating S species and during the background leachate Fe(II) was the predominant Fe oxidation state. Upon decreasing oxygen saturation and pH in the anoxic column, Fe speciation in the reference and anoxic column differed, with the relative importance of Fe(III) increasing in the anoxic column. Total Fe, pH and Eh potential measured in the leachate water did not respond to decreasing oxygen saturation, but changes in the Fe redox speciation coincided with this decrease. Under alkaline conditions, total Fe and sulfate concentrations decreased in the alkaline environment, indicating their immobilization in the solid phase. Geochemical calculations were carried out to gain further understanding of the dominant reactions in the columns. Theoretical values of Fe(II) and Fe(III) concentrations were calculated from the measured redox potential, and these were found to deviate from the measured concentrations. Therefore, estimation of Fe species distribution from redox measurements using a Pt-electrode is not considered sufficient in these systems. Mineral saturation indices of common secondary minerals associated with ARD indicated dissolution of ferrihydrite, jarosite and schwertmannite in the leachate water from the anoxic column. This suggests that these minerals are the probable source of the Fe and sulfate, as well as As and Cu released to the leachate water.

The aim of this report was to investigate the potential effects of sulfide oxidation in sediments of an arctic lake, N Luossajärvi, induced by lowered water level. Lake water, potentially contaminated by metals, was pumped into a mine tailings impoundment. The water quality in the receiving water was evaluated to see if the drainage have had an effect on the water quality. Six sediment profiles were sampled. Each profile were divided into 5 cm sections and analyzed for major elements and trace metals. Water chemistry were analyzed at six sites. As, Ni and Cu had high concentrations within undrained sediments, where As levels were classified as highly contaminated (> 27 mg kg-1 dw). Trace metals had strong statistical correlation to each other indicating a common source. The PCA analyzes performed suggests that trace metals are controlled by a common factor and drained sediments showed two additional factors controlling the variance of metals. Water chemistry had overall good status, but As, Cd, Ni and Cu exceeded natural background values. Historical data on the other hand showed no statistical difference from measured values. No effects on water quality could therefore be seen after draining of the lake, proposing high precipitation of metals within the tailing or that metals is still prevailing in the drained sediments. Metal mobility were seen within the drained sediments, where only As and Cd were presumed connected to chemical weathering and where erosion and soil properties seems to be responsible for most metal mobility.

The techniques of surface deformation and mapping are useful tools for the visualization of medical surfaces, especially for highly undulated or branched surfaces. In this thesis, two algorithms are presented for flattened visualizations of multi-branched medical surfaces, such as vessels. The first algorithm is an angle preserving approach, which is based on conformal analysis. The mapping function is obtained by minimizing two Dirichlet functionals. On a triangulated representation of vessel surfaces, this algorithm can be implemented efficiently using a finite element method. The second algorithm adjusts the result from conformal mapping to produce a flattened representation of the original surface while preserving areas. It employs the theory of optimal mass transport via a gradient descent approach. A new class of image morphing algorithms is also considered based on the theory of optimal mass transport. The mass moving energy functional is revised by adding an intensity penalizing term, in order to reduce the undesired "fading" effects. It is a parameter free approach. This technique has been applied on several natural and medical images to generate in-between image sequences.