Thesis (M. Phil.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Graduation date: 1996

Pollution prevention is promoted by the Environmental Protection Agency (EPA) and other governmental agencies as a method of reducing the generation of wastes and pollutants. Pollution prevention is also called source reduction because it reduces wastes early in the production process. Source reduction has been used by some industries to comply with governmental regulations and decrease costs associated with the management of hazardous materials. Nationally, the electronics industry generates a large quantity of hazardous waste. Similarly in Oregon, the electronics industry has recently been identified by the DEQ as one of the top five polluters in the state. The purpose of this research was to identify pollution prevention strategies that are currently being used by the electronics industry in Oregon and to assess the industry's interest in switching to less hazardous practices. A questionnaire was distributed to 180 businesses, which included all industries affiliated with the Oregon Electronics Association and additional electronics firms listed in Oregon phone directories. From those responding to the survey, the results indicated that electronics organizations in Oregon manufacture a wide variety of products including circuit boards, cable assemblies, software, laser equipment, printers, and control panels. Over half of those participating in the survey reported that the largest quantity of hazardous materials were generated early in the manufacturing process. Forty-seven percent of the respondents indicated they had attempted incorporating less hazardous compounds to those used previously. Common problems encountered which discouraged the industry from switching to less hazardous products or processes were revealed by the participants to include: The new product/process did not work as well (37%), did not believe current practices were harmful (18%), cost factors (14%), pressure from governmental agencies (3%), and other factors (28%). Fifty percent of those responding revealed that their company recycles materials within the facility. Participants indicated the products which were most likely to be recycled included cardboard (19%), office paper (18%), tin/aluminum (13%), newspaper (12%), and used chemicals (11%). The largest number of participants (43%) defined "green" or "environmentally safe/friendly" products as those that contain no known hazardous chemicals. Using this chosen definition, sixty-five percent of those responding indicated their organization did use these "green" products. It was indicated by those returning completed surveys that one reason the industry has attempted to incorporate less hazardous products and processes into their production process is primarily because of long term financial benefits. Other factors influencing the use of less hazardous materials included ethical concerns and the desire to find safer products that work as well as current products. A vast majority of respondents indicated more should be done in the area of pollution prevention and want leadership to come from within the industry itself. It is recommended that top executives in this field meet to share methods of overcoming obstacles to pollution prevention, clarify current terminology as it relates to new products, develop a system of rewarding those who are engaging in pollution prevention activities and promote technology transfer. / Graduation date: 1995

This project explored the feasibility of using fungi in a constructed wetland for the treatment of pulp mill effluent. The effluent is high in dissolved lignins (some of which are chlorinated), which have proven very difficult to degrade biologically. Mindful of work done with the (terrestrial) white rot fungi, especially Phanerochaete chtysosporium, the question is asked, Is there a fungus which can tolerate submerged conditions while degrading a significant amount of dissolved lignins? Two fungal species with lignin-degrading capability were isolated from submerged films in a log pond. These fungi have been evaluated for decolorization potential under different environmental conditions. Results of laboratory experiments show that one of these fungi, identified as Acremonium sp., was capable of 44% decolorization of pulp mill effluent under sterile, submerged, room temperature conditions. The fungal decolorization was evaluated both in floating cultures and as a film inoculated on wood chips. In addition, bench-scale examination of the potential of this fungus to decolorize pulp mill effluent in non-sterile conditions was completed. / Graduation date: 1994

Le thème général de cette thèse porte sur le comportement des sols et des roches tendres partiellement saturés. Cette condition de saturation partielle entraîne une complexification du comportement et une augmentation des couplages entre les différents phénomènes existants. Nous avons travaillé sur deux applications différentes qui présentent en fait beaucoup de similitudes. Ce travail s'est effectué principalement dans le code aux éléments finis LAGAMINE. Le premier domaine d'étude concerne le stockage de déchets nucléaires de haute activité. Pour ces derniers, le concept de dépôts dans des couches géologiques profondes a été développé afin de protéger les êtres humains et leur environnement des effets néfastes de la radioactivité. L'idée est de construire un système de galeries dans lesquelles seront placés les déchets vitrifiés ; une barrière d'étanchéité ouvragée (généralement des blocs d'argile compactée) remplira le reste de la galerie et assurera un complément à une barrière géologique naturelle. Pour dimensionner ce système complexe, il est nécessaire de bien connaître les caractéristiques hydrogéologiques, thermiques, mécaniques, chimiques et biologiques, ainsi que de comprendre les processus couplés qui ne manqueront pas de s'y développer. C'est la raison pour laquelle se sont créés des URL (Underground Research Laboratories) dans les couches géologiques potentielles, comme le SCK-CEN à Mol. Les modèles numériques viennent en complément des études expérimentales réalisées dans ces laboratoires et aident à la compréhension des mesures effectuées. En effet, le comportement de la barrière d'étanchéité est très complexe, impliquant des phénomènes thermo-hydro-mécaniques prenant place durant l'échauffement (les déchets dégagent toujours une certaine quantité d'énergie) et l'hydratation (par la formation hôte) de la barrière argileuse ouvragée. Dans ce cadre, nous avons développé un modèle d'écoulement multiphasique avec changement de phase ; il permet d'étudier les transferts hydriques et de chaleur se produisant dans la zone proche de la galerie. Les couplages sont nombreux : les variations de température influencent les propriétés des fluides, ces derniers transportent de la chaleur lors de leur déplacement (flux convectifs), ces conditions de saturation partielle (liées à la succion) induisent également des modifications du comportement mécanique de l'argile. Enfin, dans ces milieux très peu perméables, la prise en compte des transferts hydriques en phase vapeur est primordiale. Ces développements ont été réalisés dans le cadre du projet européen CATSIUS CLAY, ce qui nous a permis une comparaison avec d'autres codes de calculs et la validation de notre travail. Le deuxième domaine d'étude est la subsidence des réservoirs pétroliers de mer du Nord. En effet, certains réservoirs se situent dans des couches de craie à plusieurs milliers de mètres sous le niveau de la mer et ils sont exploités à partir d'installations off-shores. La production du pétrole induit une déplétion du réservoir qui s'accompagne d'une compaction ; cette dernière se répercute jusqu'au fond marin et cela met en danger les stations off-shores. La solution actuellement mise en uvre est l'injection d'eau dans le réservoir afin de le repressuriser et de diminuer ainsi la compaction. Malheureusement, cela a provoqué dans ces formations crayeuses un tassement supplémentaire ! Toutefois, celui-ci n'a pas que des aspects négatifs ; la compaction additionnelle permet une récupération secondaire du pétrole, qui n'aurait pu être obtenue autrement sinon. Il est donc très intéressant de pouvoir contrôler le tassement des couches réservoir. Dans le cadre des projets européens PASACHALK, nous avons développé une loi constitutive élastoplastique suivant l'idée que la sensibilité à l'eau d'une craie initialement saturée d'huile est reliée à l'effet de la succion. Cette dernière comprend des effets purement capillaires mais d'autres également (osmotiques par exemple). Nous avons donc construit un modèle multimécanisme avec influence de la succion, en utilisant les outils et concepts développés en mécanique des sols non-saturés (l'argile notamment). On voit dès lors que les modèles de l'argile de scellement et ceux de la craie de réservoir présentent de nombreuses similitudes ! Cette recherche a été facilitée par le fait qu'une craie, similaire à celles des réservoirs de Mer du Nord, affleure dans notre pays ; on l'exploite notamment dans la carrière de Lixhe, en région liégeoise. Cette craie possède les mêmes caractéristiques et propriétés que celles des formations du réservoir. La seule différence réside dans le fait qu'il n'y a jamais eu de pétrole dans ses pores ! L'analyse de l'ensemble des expérimentations réalisées sur ce matériau, nous a permis de mettre en évidence les caractéristiques du comportement de la craie de manière à calibrer notre loi. Enfin, des essais d'injection dans des échantillons nous fournissent un moyen de validation de nos modèles. Ainsi, nous avons réalisé des simulations à l'échelle du réservoir qui ont confirmé que la variation de succion est bien une explication de certaines compactions dans les réservoirs pétroliers.

Graduation date: 1994

Deep crystalline rock formations of low permeability have been identified as a possible geological medium for high-level radioactive waste disposal. In order for the safe disposal of radioactive waste, a site characterization must be performed. A comparison of site characterization methods found out-diffusion methods to be the most viable technique for pore fluid extraction. Crush and leach, chemical and isotopic analyses such as, Cl-, 37Cl, 18O, 2H and 87Sr were valuable in characterizing the signature/origin of the pore fluids. Variations in the signatures of the pore fluids were observed and attributed to small differences in heterogeneity within the host rock and water to rock interactions. Estimates of the rate of effective diffusivity (De) were evaluated experimentally and with an analytical solution. Modelled De values were much greater than those determined experimentally, suggesting that the analytical solution provides a more conservative estimate of De for assessing radionuclide migration.

Deep crystalline rock formations of low permeability have been identified as a possible geological medium for high-level radioactive waste disposal. In order for the safe disposal of radioactive waste, a site characterization must be performed. A comparison of site characterization methods found out-diffusion methods to be the most viable technique for pore fluid extraction. Crush and leach, chemical and isotopic analyses such as, Cl-, 37Cl, 18O, 2H and 87Sr were valuable in characterizing the signature/origin of the pore fluids. Variations in the signatures of the pore fluids were observed and attributed to small differences in heterogeneity within the host rock and water to rock interactions. Estimates of the rate of effective diffusivity (De) were evaluated experimentally and with an analytical solution. Modelled De values were much greater than those determined experimentally, suggesting that the analytical solution provides a more conservative estimate of De for assessing radionuclide migration.

This study first proposes a conceptual structure from Ajzen's planned behavior theory; next conducts paper review, then does practice study of waste disposal treatment; finally uses three dimensional factors and six sub-dimensional factors to examine their relationship and interaction with tendency attitude of environmental behavior. The three dimensional factors are tendency attitude, subjective norms and behavioral control perception of environmental behavior, and six sub-dimensional factors are moral perception development, environmental ethic concept, internal and exterior stakeholders' influences, self-efficacy, and instrumental ethical climate. This study conducts the empirical research by questionnaire survey and statistic analysis. The results are as follows: 1. There is significant correlation between moral perception development and business managers' decision intention on environmental ethics. 2. There is no significant correlation between environmental ethic concept and business managers' decision intention on environmental ethics. 3. There is significant correlation between internal stakeholders' influences and business managers' decision intention on environmental ethics. 4. There is significant correlation between exterior stakeholders' influences and business managers' decision intention on environmental ethics. 5. There is significant correlation between self-efficacy and business managers' decision intention on environmental ethics. 6. There is significant correlation between instrumental ethical climate and business managers' decision intention on environmental ethics. 7. There is no significant difference on demographic variables for business managers' decision intention on environmental ethics. 8. There is significant difference on some demographic variables for each dimension that influences business managers' decision intention on environmental ethics. 9. There is significant difference on some dimensions that influence business managers' decision intention on environmental ethics for different business manager groups of environmental ethic decision intention.

Thesis (Ph.D.)--Memorial University of Newfoundland, 2001. / Bibliography: leaves 232-244.