In many countries the current plan for the management of intermediate and high level radioactive wastes is to dispose of the radioactive materials underground in a Geological Disposal Facility (GDF) to prevent release of radioactivity to the environment. In the UK, the repository for intermediate level waste may be backfilled with cementitious material and it is clear that grout and cement will be used during many disposal concepts. Upon saturation, the cement will react creating a region of hyperalkaline geochemical conditions extending away from the GDF, within which, significant changes in radionuclide behaviour are expected. Therefore, this thesis utilises a range of experimental and analytical techniques to try to gain a mechanistic understanding of the behaviour of some key radionuclides (U(VI), Np(V) and Eu(III) as an analogue for Cm(III)/Am(III)) in a range of high pH systems of direct relevance to any cementitious GDF. U(VI) interaction with calcite (calcium carbonate, a common component in high pH cements and the natural environment) surfaces was studied in the 'old' (Ca(OH)2 solution; pH 10.5) and 'young' (Na+, K+, Ca2+; pH 13.3) leachates. In the 'old' leachate, luminescence spectroscopy, batch experiments and kinetic modelling suggested that at low concentrations (smaller or equal to 0.42 µM) a Ca2UO2(CO3)3-like surface complex formed. At higher concentrations, batch experiments, extended X-ray absorption fine structure spectroscopy and luminescence suggested that a surface mediated precipitation mechanism was controlling U(VI) concentrations. Further TEM analysis confirmed that a calcium uranate (CaUO4) solid phase was forming on the calcite surfaces. In the 'young' leachate, batch experiments showed that U(VI) had little affinity for the calcite surface, with no statistically relevant removal from solution observed over a 18 month period. Small angle X-ray diffraction data demonstrated that the U(VI) was probably present in the form of U(VI) intrinsic colloids. Np(V) solubility and sorption to calcite under hyperalkaline conditions were studied using batch, X-ray absorption spectroscopy, and geochemical modelling techniques. It was determined that Np(V) solubility in 'old' cement leachates was consistent with the literature. However, in 'young' cement leachates, an unidentified calcium containing phase was controlling solubility. It was demonstrated that sorption to calcite in 'old' leachates was controlled by the formation of a >CO3NpO2 surface complex, whereas, in the 'young' leachates interaction with the calcite surface was controlled by a precipitation mechanism. Eu(III) sorption to a potential GDF backfill material, Nirex Reference Vault Backfill (NRVB) cement, was studied. The kinetics of removal were rapid with 98.5% Eu(III) removal within 24 hours. Ultrafiltration experiments indicated that all Eu(III) remaining in solution was associated with NRVB derived colloids. Additional experiments using ethylenediaminetetraacetic acid (EDTA) as a competing ligand show that removal from solution was significantly reduced at high concentrations (>0.01 M). These EDTA experiments also indicated some irreversibility in the systems, possibly caused by incorporation into the C-S-H or calcite structures.

The purpose of the studies included in this thesis is to develop an effective an efficient method to study the proteome using separation and detection of peptides, when only a limited amount of sample, 10 micrograms of total protein or less, is available. The analysis will be applied to multiple myeloma cancer cells using ultra high-performance liquid chromatography-mass spectrometry for expression proteomics to illustrate utility. To detect low abundance peptides in a complex proteome, we use different strategies, including basic pH reversed-phase liquid chromatography (bRPLC), mass-to-charge fractionation in the mass spectrometer, and various liquid chromatography gradients to increase peptide separation to improve opportunities for detection and quantification. The different methods are optimized and compared by the number of peptides detected. Step-wise elution of bRP spin columns proved to yield more than 36,000 peptides using only 10 μg of protein. Mass-to-charge (m/z) fractionation was tested in mass analyzer Q-Exactive Plus (Thermo Scientific). Liquid chromatography-tandem mass spectrometry (LC-MS/MS) of an unfractionated sample was analyzed 4 times at different mass ranges, each mass range width of 150 m/z, resulting from 4 spectra combined, 31,732 peptides representing 3,967 proteins. Showingcomparable results to those form high pH reversed phase fractionation spin columns 5 fractions. Establishing a benchmark where the LC-MS/MS analysis of 600 μg of 10plex TMT-labeled peptides fractionated with bRPLC into 24 fractions yielded over 74,000 peptides from 7,700 proteins, we compared those results with analysis of 10 μg of total TMT-labeled peptides fractionated by bRP spin columns into 5 fractions, which produced 14,019 peptides from 3,538 proteins. These experiments were used to relatively quantify protein expression in naïve and drug resistant multiple myeloma cells lines as an example application in cancer research.

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Calcite stalactites ranging in length from several inches to a foot long are found forming on the southeastern slag pile at the former Gadsden Steel Mill of the Gulf States Steel Corporation. Analyses of samples collected per EISOPQAM guidelines include the following: petrographic, conductivity, pH, XRD, XRF, TDS, and major cations and anions. Preliminary field pH and conductivity measurements indicate that waters near the slag pile have a pH ranging from 11-12 and a conductivity ranging from 1115-6300 μS/ cm. Titration data indicate that the maximum pH value is 12.5. These calcite stalactites and stream coatings result from the dissolution of the steelmaking slag by rainfall. These alkaline waters precipitate calcite when they are in contact with atmospheric CO2. Improper management of slag products can lead to aesthetically impacted environments and ecosystems. Several studies and this study show that steel slag could be used to sequester atmospheric CO2.

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