<p> Coal tar is a rich source of polycyclic aromatic compounds (PAC) which include hydrocarbons (PAH), sulfur-containing aromatics (PASH), nitrogen-containing aromatics and high molecular mass PAH. The separation of coal tar into four fractions was carried out on activated (170°C, 48 hrs) neutral alumina. Low mass aromatics and aliphatics were eluted with hexane in fraction A1 (2.2% recovery), while PAH/PASH were eluted by benzene in fraction A2 (25%). High molecular mass PAH were eluted by dichloromethane in fraction A3 (5.5%) and nitrogen-containing aromatics were eluted by methanol in fraction A4 (21%). These fractions were characterized by normal phase liquid chromatography, GCMS, probe mass spectrometry (for fractions A3 and A4) and LC-MS (for fraction A3).</p> <p> While ratio of PASH to PAH in fraction A2 was rather unfavorable (25:1), the separation of PASH from PAH was attempted using two methods: an oxidation/reduction method and a ligand exchange method. The oxidation/reduction method of Lee was a complete failure. The PdCl2-silica method of Nishioka was partially successful. Of the 25 thia-arenes identified in fraction A2, 12 eluted with the PAH while the other 13 were either partially (5) or fully (8) retained by the PdCl2-silica gel column and then eluted later to give a sulfur-enriched fraction. This fraction was further separated using normal phase HPLC to afford sulfur-containing compounds with molecular masses between 184 amu and 258 amu which exhibited almost no contamination due to PAH. Thus, it would be possible to purify about one-half of the PASH from a complex mixture such as coal tar.</p> <p> Fraction A3 which contained high mass PAH was subjected to semi-preparative normal phase HPLC to afford several high molecular mass PAH fractions. The 326 amu PAH fraction was selected because it contributed to 10% of the genotoxic of the mixture. This fraction was further separated by normal phase HPLC and the subfractions were analyzed by reversed-phase HPLC with diode-array detection. Thirty-five peaks were collected from the reversed-phase HPLC analysis and were characterized by probe mass spectrometry and fluorescence spectroscopy (in part). Of the 35 peaks, 8 peaks were eluted in the mutagenic active range; these eight compounds will be evaluated using the Ames assay to determine which are active mutagens.</p> / Thesis / Master of Science (MSc)

Sites contaminated with polycyclic aromatic hydrocarbons can be simultaneously contaminated with trace elements. Co-contaminated soil is considered a complex problem since inorganic and organic contaminants behave differently and thereby often require different remediation strategies. Despite the fact that co-contaminated soils are a common problem, existing research on remediation of contaminated soil mostly focuses on either organic or inorganic contaminants. In the present study, the possibilities of electrokinetic remediation as an alternative to commonly used remediation technologies was investigated. An experiment was setup to evaluate the effects of electrokinetic remediation on both polycyclic aromatic hydrocarbons and trace elements, such as arsenic, cadmium, chromium, copper, lead and zinc, simultaneously. The experiment was performed in 12 litre large plexiglass cells. Two cells with electrokinetic treatment, equipped with iron electrodes, to amend the soil with iron via intentional corrosion of the electrodes, and one control. The cells were filled with contaminated soil and deionized water was pumped through the cells to simulate a groundwater flow. The experiment ran for two months, during which pore water was sampled weekly and simulated groundwater monthly, to monitor changes in contaminant concentrations. Soil samples were taken at the start and at the end of the experiment. Results showed that the concentration of polycyclic aromatic hydrocarbons in the simulated groundwater decreased from 0.39 ± 0.15 μg L-1 to 0.12 ± 0.064 μg L-1 during the experiment. However, at the point of writing, samples of soil at the end of the experiment has not yet been analysed for concentration of polycyclic aromatic hydrocarbons, something that needs to be done to validate previously described results. In terms of the trace elements, the applied method did not increase their mobility, nor did it decrease it. Moreover, the trace elements behaved similarly in the control cell as in the treatment cells. This was observed for all the tested trace elements, indicating that electrokinetic remediation in this particulate case may be a suitable remediation technology for organic, but not that successful for inorganic contaminants. In regard to this, further research is required to establish whether electrokinetic remediation is a promising remediation technology for co- contaminated soil and how it can be optimized to ensure remediation success for both organic and inorganic contaminants.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.