Self-heating in coal has been studied for well over one hundred years, yet there is no accurate or reliable method for predicting the potential of certain coals to undergo self-heating. Fires caused by self-heating, and eventually spontaneous combustion, have occurred in the high wall of surface mines, in underground mines, in coal stockpiles, and on trains, barges and ships. Self-heating in coal is brought about through a complex interplay of conditions depending on the specific properties of the coal as well as many external factors involved in the mining and handling of coal. In a study supported by the United States Department of Transportation and monitored by the United States Coast Guard, data on over 2000 barges of coal was incorporated into a data bank. Results from the evaluation of these data and from a barging study, in which a research crew accompanied a tow of barges from western Kentucky to the New Orleans area, were used to make recommendations to minimize self-heating in barged coal. An inexpensive adiabatic calorimeter (accelerating rate calorimeter) was constructed and used to obtain supporting laboratory data on coal samples collected in the barging study. There is very good agreement between the results obtained with the calorimeter concerning the reactivity of coals and susceptibility of the coals to undergo selfheating as would be predicted using chemical and physical data from the data bank.

Abstract The electrocatalysis of oxygen plays a significant role in several electrochemical energy storage and conversion systems including metal−air batteries, fuel cells, electrocatalytic and photocatalytic water splitting. The sluggish kinetics and complex reaction mechanism of this cathodic oxygen reduction reaction (ORR) affect the performance and practical application of such renewable energy technologies. To address this limiting factor, a suitable electrocatalyst is required for ORR. In general, platinum or highly dispersed Pt-based nanoparticles on carbon black are considered as the best ORR catalyst. But platinum being very scarce and expensive tends to increase the cost. Moreover, platinum-based catalysts are prone to several serious problems, including declining activity, the fuel-crossover, and poisoning effects. This has initiated overwhelming research attention towards the development of low cost ORR catalysts. Jasinski et al. pioneered in reporting that a N4-chelate complex with a transition metal could be used for electrochemical oxygen reduction. Subsequently many nonprecious ORR catalysts have been investigated so far to replace platinum which include transition metal chalcogenides, nitrogen-doped carbon nanotubes or graphene, carbon nitride, and metal-N4 chelate macrocycles (M-N4-macrocycles). However, most of these current catalysts exhibited insufficient activity and low stability in corrosive environment of fuel cells. Thus, new strategies to develop catalysts which can meet the combined requirements of low cost, high catalytic activity and long-term durability still remains a challenge. Recently our group has reported synthesis of heteroatom doped porous carbon through chemical activation of simple monomers. The facile synthetic route, high surface areas with abundant micropores, inherent presence of heteroatoms and tunable structure/composition at the molecular level make them potential for high-performance ORR electrocatalysts. To increase the catalytic performance in both acidic and basic media, it is important to incorporate or coordinate the doped heteroatom centers with 3d transition metals such as iron or cobalt. Herein, two different synthetic strategies will be presented to synthesize transition metal-based heteroatom doped porous carbon as ORR catalyst. In the first approach, iron (III) thiocyanate as iron salts was pyrolyzed with benzimidazole to introduce sulfur along with nitrogen and iron in the porous carbon. Another synthetic approach involved hydrothermal synthesis of cobalt oxide on the surface of benzimidazole derived porous carbon. ORR can proceed via either one step four-electron reduction pathway producing water or two step two-electron reduction pathway producing HO2-, OH- and H2O2. Both of these synthesized catalysts favored 4e- reduction pathway which is energetically efficient and do not produce corrosive byproducts. The electrochemical performance of the synthesized catalyst will be analyzed by cyclic voltammetry, linear sweep voltammetry and amperometric i-t technique and compared with commercially available 20 wt% Pt based carbon in both acidic and basic media. The effect of pore size, nitrogen content, bonding configurations of nitrogen and sulfur, influence of cobalt and iron on ORR performance will also be discussed.

Studies have shown that some canines have the ability to predict seizures in people with epilepsy, and that canines can be trained to recognize changes in humans before an epileptic seizure and make these predictions. It is not known with any certainty to what the canines are alerting. However, canines’ exceptional sense of smell and their ability to discriminate human scent is well established. Therefore, it is possible that the canines could be responding to an olfactory cue, such as the release of some volatile organic compounds (VOCs) prior to the onset of a seizure. Individuals release a wide array of VOCs, both odorous and non-odorous, from their bodies. The odorous VOCs collectively make up human scent and a number of these VOCs have been identified as biomarkers of different diseases. Evidence suggests that canines can perceive these biomarkers, leading to early detection of underlying physical ailments before individuals are aware of their own symptoms. The main purpose of this study was to use headspace solid phase microextraction (HS-SPME) with gas chromatography-mass spectrometry (GC-MS) to analyze hand odor, saliva and breath samples from epileptic with and without seizure activity to determine if the human scent profiles resulting from a seizure event differs from the scent profiles in the absence of seizure activity. the HS-SPME-GC-MS method was also used to analyze and compare hand odor, saliva and breath samples of healthy individuals and epilepsy patients to determine if the profiles can be differentiated. Comparison of the VOCs in each specimen from healthy individuals and epileptic patients revealed compounds that could be used as potential biomarkers to differentiate between healthy and epileptic individuals. Comparison of the VOCs in each specimen from epileptic patients with and without seizure activity revealed compounds that could be used as potential biomarkers for epileptic seizures. Finally, canine trials were used to verify that these compounds are indeed biomarkers.

L'analyse de traces dans les fluides biologiques est fréquemment précédée d'une étape d'extraction afin de limiter la présence d'interférents. Ainsi, l'extraction sur phase solide (SPE) est souvent utilisée en amont des techniques séparatives, mais son manque de sélectivité peut conduire à des co-extractions de composés interférents nuisant à l'analyse. L'utilisation d'outils basés sur une reconnaissance moléculaire tels que les immunoadsorbants (IS), utilisant des anticorps, ou les polymères à empreintes moléculaires (MIP) qui sont des polymères synthétiques avec des cavités complémentaires de la molécule empreinte en taille, forme et fonctionnalité, peut apporter de la sélectivité à l'analyse. La miniaturisation d'un système de séparation permet d'augmenter la sensibilité des analyses. Ainsi, le couplage d'une extraction miniaturisée sur MIP présente un intérêt par sa sélectivité. Celui-ci a donc été étudié pour l'extraction de la cocaïne et ses métabolites, la benzoylecgonine (BZE) et l'ecgonine méthylester (EME), comme molécules modèles, dans diverses matrices biologiques. Les performances d'une puce commerciale intégrant un canal d'enrichissement, un canal de séparation et une aiguille métallisée pour la formation d'un électrospray ont été initialement évaluées. La méthode d'analyse développée a montré d'excellents résultats en termes de sensibilité (limites de quantification de quelques dizaines de pg mL-1), et a donc été appliquée à l'analyse de traces de cocaïne et de BZE dans l'urine et les cheveux. Malgré les bons résultats obtenus, le manque de spécificité de l'étape d'extraction a finalement limité le potentiel de la méthode miniaturisée, d'où l'intérêt d'y intégrer un outil sélectif. Pour confirmer la faisabilité d'un MIP sélectif pour la cocaïne, des synthèses en format conventionnel ont été étudiées. Après optimisation de la synthèse et des protocoles d'extraction, une excellente sélectivité a été obtenue en milieu organique pour la cocaïne et ses métabolites. Cependant, en milieu hydro-organique ou aqueux pour la BZE n'a pas été retenue. Le MIP a par la suite été appliqué avec succès à l'extraction sélective de la cocaïne d'extraits de cheveux, de sérum et d'urine. Pour mettre à profit le potentiel sélectif du MIP pour les trois molécules ciblées, une étape préalable d'extraction liquide-liquide a été appliquée sur un échantillon urinaire, ce qui a permis de mettre de nouveau en évidence le potentiel du MIP pour la purification en milieu complexe. La dernière partie de ce travail a consisté à synthétiser un MIP sélectif pour la cocaïne dans un format miniaturisé. La première approche a reposé sur la synthèse de microparticules de MIP par précipitation. Plusieurs paramètres clés de la synthèse ont été étudiés afin d'obtenir des particules de NIP et de MIP de tailles proches de 3 μm. Malheureusement, le MIP ainsi obtenu ne s'est pas avéré sélectif vis-à-vis de la cocaïne et ses métabolites, ni dans un milieu organique ni dans un milieu aqueux. La deuxième approche a consisté en la synthèse de monolithes de MIP dans des capillaires de silice (100 μm d.i.). Divers paramètres ont été étudiés pour l'obtention d'un monolithe de MIP avec une morphologie appropriée au couplage avec la nanochromatographie en phase liquide. Le MIP ainsi sélectionné a présenté une meilleure affinité pour la cocaïne que le NIP correspondant en milieu acétonitrile, et sa synthèse s'est avérée répétable en termes de morphologie et de sélectivité. Un couplage a donc été effectué et, si ce dispositif nécessite encore une étude plus approfondie, des résultats très encourageants ont été obtenus pour l'extraction en ligne de la cocaïne d'échantillons urinaires dopés.

Depuis une vingtaine d'années, la société a subi de nombreux actes terroristes mortels. Encore aujourd'hui, il est parfois difficile d'identifier avec précision la composition de l'engin explosif utilisé compte tenu de la complexité des échantillons générés (huile de moteur, sang, débris calcinés,...) et de la présence des résidus d'explosifs à de faibles concentrations. Une étape de purification de l'échantillon et de préconcentration de ces explosifs est donc nécessaire avant leur analyse chromatographique pour permettre une identification et une quantification aisée. L'extraction sur phase solide (SPE) est devenue la méthode de choix pour ce type de traitement de l'échantillon. Divers supports d'extraction sont disponibles mais ils peuvent entraîner des coextractions d'interférents gênant alors l'analyse. A cet effet, des supports polymériques, appelés MIP (molecularly imprinted polymers) et générant une rétention basée sur un mécanisme de reconnaissance moléculaire, ont été envisagés comme support d'extraction sélective des nitroaromatiques, explosifs les plus couramment utilisés. Dans un premier temps, des supports synthétisés en bloc par voie radicalaire ont été préparés. La présence unique des groupements nitro des composés ciblés n'ont pas permis le développement d'interactions polaires suffisamment fortes pour obtenir la création de cavités spécifiques lors de la synthèse. Seule l'exploitation d'interactions hydrophobes et/ou de type π-π avec le styrène comme monomère a permis de former des cavités sélectives vis-à-vis du 2,4-dinitrotoluène (2,4-DNT) et du 2,4,6-trinitrotoluène (2,4,6-TNT) pour entrevoir un faible degré de sélectivité lors de l'extraction. En conséquence, une toute autre approche de synthèse par voie sol-gel a été envisagée afin d'extraire sélectivement les nitroaromatiques des matrices complexes. La synthèse de ces supports de silice étant réalisée en milieu aqueux, la formation des cavités spécifiques a reposé sur la forte interaction entre la molécule empreinte (2,4-DNT) et le monomère (phényltriméthoxysilane) utilisé pour le développement d'interactions hydrophobes et de type π-π. Différents supports ont été synthétisés, notamment avec trois ratios molaires molécule empreinte/monomère/agent réticulant différents et caractérisés par l'établissement de profils d'élution et l'estimation de leur capacité. Au final, un support de silice imprimé a permis l'extraction simultanée et sélective, pour la première fois à notre connaissance, de quatre nitroaromatiques (2,4-DNT, 2,4,6-TNT, le 2,6-DNT et le tétryl) avec des rendements supérieurs à 88 ± 4 % (n = 3). Ces résultats ont été confirmés par l'extraction en milieu réel dans des matrices telles que l'huile de moteur et le sang et par comparaison avec un support conventionnel. Compte tenu du grand potentiel de ce type de support pour l'extraction sélective, il a ensuite été envisagé de miniaturiser l'ensemble des outils analytiques afin d'évoluer vers un dispositif de diagnostic de terrain. Pour cela, une extraction en ligne nécessitant une faible quantité de support a été mise en place démontrant ainsi la possibilité de miniaturiser l'étape d'extraction. Dans un second temps, une méthode de détection électrochimique du 2,4,6-TNT sur électrode imprimée a été développée avec succès. En associant en amont une purification de l'échantillon sur MIS, ce dispositif constitue un premier pas vers le diagnostic de terrain.

Nous avons mis en évidence l'intérêt des groupements carboxyliques greffés pour l'immobilisation directe et dense de nanoparticules coeur-coquille gamma-Fe2O3@SiO2 amino fonctionnalisées sur des surfaces macroscopiques. Les groupements carboxyliques sont greffés sur des surfaces d'or ou de carbone vitreux via la réduction cathodique du 4 carboxyphényl diazonium. Cette approche offre la possibilité d'un assemblage dense rigide et irréversible des nanoparticles sur ces deux surfaces. Plusieurs techniques d'analyses de surface (électrochimie, IRRAS, MEB, ellipsométrie, AFM, profilométrie) ont été utilisées pour caractériser les couches obtenues à l'issue des différentes étapes de l'assemblage. La caractérisation par voltamétrie cyclique de la couche de nanoparticules formée n'est possible que sur carbone vitreux et parmi les deux sondes rédox utilisées, seul le ferrocyanure dans l'eau permet d'observer un effet. Les études par voltamétrie cyclique montrent que la vitesse de transfert de charge d'une sonde rédox dépend de l'état de la surface de l'électrode et permet d'estimer un taux de recouvrement de celle-ci, aussi bien par le film organique que par les nanoparticules. L'éventualité d'utiliser nos supports pour fabriquer des nanoparticules asymétriques de type " Janus " a été rapidement abordée. Nous avons montré qu'il était possible de réaliser un deuxième assemblage : nanoparticules NH2 / fluorescéine ou nanoparticules NH2 / nanoparticules COOH. Les essais que nous avons réalisés dans une cellule à écoulement montrent que la procédure serait mieux adaptée dans un système à flux continu du type microcanal fluidique. C'est dans cette voie que l'on pourrait poursuivre ces travaux. Il serait aussi intéressant de mener une étude en fonction du pH dans ces canaux afin de mieux contrôler l'immobilisation et le décollement des nanoparticules. Finalement, nous avons immobilisé localement les nanoparticules coeur-coquille gamma-Fe2O3@SiO2 amino fonctionnalisées sur les motifs de polystyrène oxydé que nous avons réalisés par SECM.

The radial heterogeneity of some columns used in high performance liquid chromatography (HPLC) was investigated using an on-column microelectrochemical amperometric detector. Such a detector allowed the recording of the elution profiles at different spatial positions throughout the column exit cross-section. From this, we obtain information about the radial distribution of the mobile phase velocity, column efficiency, and analyte concentration. In all cases, the results obtained show that the spatial distribution of the mobile phase velocity does not follow a piston-flow behavior but exhibits radial heterogeneity with differences not exceeding 5% between the center and wall regions of any column. The efficiency was found to be lower in the wall region of the column than in its core region (the central core with a radius of 1/3 the column inner radius) by up to 40-50% in some columns. The radial distribution of the maximum concentration of the peaks varies throughout the column exit section, partially due to the radial variations of the column efficiency. The technology used in constructing the microelectrochemical detectors was further exploited to fabricate and incorporate an online detector array for a pressurized flat wide column measuring 10x10x0.1 cm in dimensions. Thus, unlike traditional thin layer chromatography, samples in this pressurized flat bed are completely eluted and detected in a time-based mode just like they are in HPLC. Also, a lateral arrangement of the detector array allows for an easy monitoring of the homogeneity of the flat wide column. Also, information on the surface properties of three novel chemically bonded phase packing materials for HPLC was obtained using solid state cross-polarization (CP) magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopic experiments for the 29Si, and 13C nuclei. These packing materials were: Cogent bidentate C18 bonded to type-C silica, hybrid packing materials XTerra MS C18, and XBridge Prep. C18. The spectra obtained using cross-polarization magic angle spinning (CP-MAS) on the Cogent bidentate C18 bonded to type-C silica show the surface to be densely populated with hydride groups (Si-H), with a relative surface coverage exceeding 80%. The hybrid packing materials XTerra and XBridge gave spectra that reveal the silicon atoms to be bonded to alkyl moieties embedded in the molecular structure of these materials with over 90% of the alkyl silicon atoms found within the completely condensed silicon environments.

This Thesis describes applications of standing-waveultrasonic traps for sensitive biomedical analysis. Two majorapproaches have been investigated where functionalizedmicroparticles are employed in bioaffinity assays. In the firstapproach, a longitudinal flow-through capillary ultrasonic trapis used for size selective separation and retention ofdifferently sized microparticles. This device may be used fordetection of particle pairs, which are formed during theinitial stage of microparticle immunoagglutination. Theperformance of the capillary ultrasonic trap for enrichment andcounting of particle pairs is characterized by a model systemof differently sized homogeneous fluorescent microparticles.The selectivity of this detection method relies on thecharacteristics of the force field inside the narrow borecapillary, which is formed by the competition between acousticradiation forces and viscous drag forces from the fluidflow. The second approach is an investigation of the potential forsensitive protein quantification by combining ultrasonicenrichment and confocal laser-scanning fluore-scence detection.Here, the design of the ultrasonic trap is tailor-made for theimaging properties of a confocal microscope, resulting inrearrangement and concentration of suspended microparticlesinto single, dense layers that is scanned by a focused laserbeam. The bioaffinity assay employed is based on detecting thetarget molecules via fluorescent tracer antibodies immobilizedon the surface of each single particle. The final part of the work presented in this Thesis is athorough investigation of both the biochemical and the physicalproperties that determine the performance and potentialsensitivity of the particle doublet assay. In thisinvestigation, a novel approach is presented for doubletdetection, namely fluorescence-microscopy-based classificationof doublets and singlets by a pattern recognition algorithm.The experimental results are also compared with the resultsfrom flow cytometry analysis. Furthermore, the initial stage ofimmuno-agglutination is theoretically investigated by a modelbased on diffusion-limited agglutination combined with a stericfactor determined by the geometry of the bio-molecules and theamount of specific and non-specific binding that is present inthe particular assay. To conclude, the Thesis presents several approaches wherestanding-wave ultrasonic fields may be used for sensitiveparticle-based biomedical analysis. The best prospect for highsensitivity was found for the confocal laser-scanningfluorescence detection system, with a detection limit of theorder of 10-14M. On the other hand, the agglutination-basedassay may give sensitivity of the order of 10-11-10-10M with very simple and inexpensiveequipment.

The novel application of combination, or two stage, photochemical and microbial degradation systems for removal of resin acids from natural river water and single stage photolysis for degradation of naphthenic acids in natural river water was investigated. The organic compounds included in this project comprise naphthenic acid model compounds and mixtures as well as four resin acids. Naphthenic acids are crude oil-derived and accumulate to significant concentrations (>100 mg/L) in tailings pond water at oil sands extraction facilities. Resin acids are pulp and paper mill-derived compounds that tend to persist at low levels in receiving waters. For each compound group, analytical methods utilizing liquid chromatography negative ion electrospray ionization mass spectrometry (LC/ESI/MS) were developed. The main hurdle to developing analytical methods for the naphthenic acids and resin acids are related to their polarity, complexity, and lack of available standards for the various individual components. As well, co-extractives, such as humic and fulvic acids, tend to interfere with the detection of naphthenic acids in aquatic samples (Headley et al., 2002a). Resin acid mixtures are not as complex as the naphthenic acids, although each group of hydrocarbon acids may include several isomeric compounds. The application of photochemical degradation prior to biodegradation was proven to be effective here for rapid degradation of the resin acids. In general, the resin acid precursors were more susceptible to the photolysis than were the naphthenic acids. Through thermal maturation and increased complexity, the naphthenic acids seemingly become more resistant to degradation, as evidenced by their commercial use as anti-microbial agents and the observed resistance to photolysis noted in this research. The results of this research may be significant for the design of staged treatment for reduced microbial shock loading and increased bioavailability (defined here as the ability of microbial organisms to degrade the target contaminants) in both bioremediation systems and receiving waters. Specifically, four selected pulp and paper mill-associated resin acids were exposed to several ultraviolet/visible (UV/vis) spectrum radiation sources in water collected from the River Saale in Germany. Background resin acid concentrations were observed in water collected in 2001 and 2002 from various locations along the well-forested River Saale and a manuscript detailing these results published. Analyses of water samples collected in the pulp and paper milling region of the river (in the state of Thuringia) indicated that resin acids persist through biodegradation treatment systems and for several hundred kilometres downstream. All four resin acids were degraded by facile photochemical and microbial degradation with pseudo-first-order kinetics. Half-life values were in the ranges of 18 to 200 minutes for photolysis applications, 8 to 40 hours for biodegradation applications and 3 to 25 hours for two-stage photochemical-microbial degradation processes, in which photolysis was limited to three hours. From these results, it was shown conclusively that photolysis pre-treatment is a viable and efficient method for reducing both resin acid concentrations and the associated acute toxicity. The naphthenic acids investigated in this study were not effectively degraded via UV/vis radiation, including UV-A/UV-B radiation between 300-400 nm, near-monochromatic UV254-radiation, full spectrum artificial solar radiation and natural sunlight. The photochemical degradation potential of three model naphthenic acid compounds and three naphthenic acid mixtures (one extract from the Athabasca Oil Sands and two commercial mixtures) were examined in Athabasca River water. Photolysis at UV254 was the most successful degradation source in all instances, although most naphthenic acids were not significantly degraded by any of the radiation sources. Therefore, it was determined that photolysis is not likely to contribute significantly to environmental degradation and attenuation in the aquatic ecosystem. The results observed from the various naphthenic acids photodegradation processes, coupled with their low affinity for adsorption to soils, reveal that naphthenic acids are likely to persist in the water column. However, UV/vis radiation is capable of significantly changing the composition of mixtures in the aquatic ecosystem, but not reducing overall naphthenic acid concentrations. This may not be a beneficial as there is the potential for increased toxicity toward the lower molecular weight naphthenic acids.

The novel application of combination, or two stage, photochemical and microbial degradation systems for removal of resin acids from natural river water and single stage photolysis for degradation of naphthenic acids in natural river water was investigated. The organic compounds included in this project comprise naphthenic acid model compounds and mixtures as well as four resin acids. Naphthenic acids are crude oil-derived and accumulate to significant concentrations (>100 mg/L) in tailings pond water at oil sands extraction facilities. Resin acids are pulp and paper mill-derived compounds that tend to persist at low levels in receiving waters. For each compound group, analytical methods utilizing liquid chromatography negative ion electrospray ionization mass spectrometry (LC/ESI/MS) were developed. The main hurdle to developing analytical methods for the naphthenic acids and resin acids are related to their polarity, complexity, and lack of available standards for the various individual components. As well, co-extractives, such as humic and fulvic acids, tend to interfere with the detection of naphthenic acids in aquatic samples (Headley et al., 2002a). Resin acid mixtures are not as complex as the naphthenic acids, although each group of hydrocarbon acids may include several isomeric compounds. The application of photochemical degradation prior to biodegradation was proven to be effective here for rapid degradation of the resin acids. In general, the resin acid precursors were more susceptible to the photolysis than were the naphthenic acids. Through thermal maturation and increased complexity, the naphthenic acids seemingly become more resistant to degradation, as evidenced by their commercial use as anti-microbial agents and the observed resistance to photolysis noted in this research. The results of this research may be significant for the design of staged treatment for reduced microbial shock loading and increased bioavailability (defined here as the ability of microbial organisms to degrade the target contaminants) in both bioremediation systems and receiving waters. Specifically, four selected pulp and paper mill-associated resin acids were exposed to several ultraviolet/visible (UV/vis) spectrum radiation sources in water collected from the River Saale in Germany. Background resin acid concentrations were observed in water collected in 2001 and 2002 from various locations along the well-forested River Saale and a manuscript detailing these results published. Analyses of water samples collected in the pulp and paper milling region of the river (in the state of Thuringia) indicated that resin acids persist through biodegradation treatment systems and for several hundred kilometres downstream. All four resin acids were degraded by facile photochemical and microbial degradation with pseudo-first-order kinetics. Half-life values were in the ranges of 18 to 200 minutes for photolysis applications, 8 to 40 hours for biodegradation applications and 3 to 25 hours for two-stage photochemical-microbial degradation processes, in which photolysis was limited to three hours. From these results, it was shown conclusively that photolysis pre-treatment is a viable and efficient method for reducing both resin acid concentrations and the associated acute toxicity. The naphthenic acids investigated in this study were not effectively degraded via UV/vis radiation, including UV-A/UV-B radiation between 300-400 nm, near-monochromatic UV254-radiation, full spectrum artificial solar radiation and natural sunlight. The photochemical degradation potential of three model naphthenic acid compounds and three naphthenic acid mixtures (one extract from the Athabasca Oil Sands and two commercial mixtures) were examined in Athabasca River water. Photolysis at UV254 was the most successful degradation source in all instances, although most naphthenic acids were not significantly degraded by any of the radiation sources. Therefore, it was determined that photolysis is not likely to contribute significantly to environmental degradation and attenuation in the aquatic ecosystem. The results observed from the various naphthenic acids photodegradation processes, coupled with their low affinity for adsorption to soils, reveal that naphthenic acids are likely to persist in the water column. However, UV/vis radiation is capable of significantly changing the composition of mixtures in the aquatic ecosystem, but not reducing overall naphthenic acid concentrations. This may not be a beneficial as there is the potential for increased toxicity toward the lower molecular weight naphthenic acids.