Greenhouse gases (GHGs) are vital components of the earth�s atmosphere, trapping heat around the earth, maintaining temperatures necessary for human existence. Until the Industrial Revolution, these gases existed in a natural equilibrium with the environment. Since that time, anthropogenic activities such as fossil fuel burning and land clearing have increased the quantity of GHGs, such as carbon dioxide (CO2) and methane (CH4), in the earth�s atmosphere. Evidence indicates that global warming is occurring as a result of the additional accumulation of GHGs in the atmosphere. International response to climate change resulted in the 1997 development of the Kyoto Protocol. If the Protocol is ratified, developed countries will be legally bound to reduce their GHG emissions in accordance with negotiated emission reduction targets. At the beginning of the year 2001, the Protocol was still to be ratified. With the possibility of future GHG emission restrictions, some Australian companies have started quantifying their GHG emission levels. One such company is Visy Industries, the largest privately owned paper packaging manufacturing company in the world. Visy�s core business is the manufacture of cardboard boxes from recycled paper. As part of its future operations, a kraft pulp and paper mill is presently being built in New South Wales, Australia. The environmental decision support tool, Life Cycle Assessment (LCA), was used to quantify Visy�s CO2 and CH4 emissions across the entire life cycle of the Visy paper recycling and virgin papermaking processes. Commercially defined LCA models were developed for both papermaking processes. GHG emissions estimated by each model were compared and the effect of different energy sources, technologies and manufacturing processes on CO2 and CH4 emissions were assessed. The majority of emissions in the two Visy papermaking models were due to fossil fuel derived energy sources and the decomposition of wood fibre in Solid Waste Disposal Sites (SWDSs). Results were used to propose appropriate GHG reduction strategies and business opportunities. GHG reduction strategies included increasing the use of renewable energy, reducing the volume of solid waste rejects sent to SWDS, incinerating solid waste rejects with energy recovery and sourcing steam from third party providers. Proposed GHG business opportunities included increasing the production of Greenpower from the pulp and paper mill for sale to the grid. This thesis is an example of the practical application of current GHG knowledge and LCA methodology that was undertaken in an environment where technical, political and commercial guidelines at both a national and international level were still evolving. Nevertheless, the thesis is not a critical review of LCA methodology. The LCA support tool was able to quantify CO2 and CH4 emissions across the life cycle of the Visy recycling and virgin papermaking processes. The chosen functional unit, the assumptions and exemptions made, and the placement of the system boundaries, were found to be critical to the Visy LCA results.

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Bioethanol is likely to be a large contributor to the fuel sector of industry in the near future. Current research trends are geared towards utilizing food crops as substrate for bioethanol fermentation; however, this is the source of much controversy. Utilizing food crops for fuel purposes is anticipated to cause massive food shortages worldwide. Cellulose is the most abundant renewable resource on earth and is subject to a wide array of scientific study in order to utilize the glucose contained within it. Waste paper has a high degree of cellulose associated with it, which makes it an ideal target for cellulose biotechnology with the ultimate end goal of bioethanol production. This study focussed on producing the necessary enzymes to hydrolyse the cellulose found in waste paper and using the sugars produced to produce ethanol. The effects of various printing inks had on the production of sugars and the total envirorunental impact of the effluents produced during the production line were also examined. It was found that the fungus Trichoderma longibrachiatum DSM 769 grown in Mandel's medium with waste newspaper as the sole carbon source at 28 °C for 6 days produced extracellular cellulase enzymes with an activity of 0.203 ± 0.009 FPU.ml⁻¹, significantly higher activity as compared to other paper sources. This extracellular cellulase was used to hydrolyse waste newspaper and office paper, with office paper yielding the highest degree of sugar production with an end concentration of 5.80 ± 0.19 g/1 at 40 °C. Analysis by HPLC showed that although glucose was the major product at 4.35 ± 0.12 g/1, cellobiose was also produced in appreciable amounts (1.97 ± 0.71 g/1). The sugar solution was used as a substrate for Saccharomyces cerevisiae DSM 1333 and ethanol was produced at a level of 1.79 ± 0.26 g/1, the presence of which was confirmed by a 600 MHz NMR spectrum. It was found that cellobiose was not fermented by this strain of S. cerevisiae. Certain components of inks (the PAHs phenanthrene and naphthalene) were found to have a slight inhibitory effect (approximately 15% decrease) on the cellulase enzymes at very high concentrations (approximately 600 μg/1 in aqueous medium), while anthracene had no effect. Whole newsprint ink was shown not to sorb glucose. The environmental analysis of the effluents produced showed that in order for the effluents to be discharged into an aqueous ecosystem they would have to be diluted up to 200 times. They were also shown to have the potential to cause severe machinery damage if reused without proper treatment.

Polyamideamine epichlorohydrin (PAE) resin is a water soluble additive and the most used permanent wet strength additive in alkaline conditions for preparing wet strengthened papers. In this thesis, we studied some properties of PAE resins and wet strengthened papers prepared from them. In order to elucidate PAE structure, liquid state, 1H and 13C NMR was performed and permitted signals assignment of PAE structure. PAE films were prepared to study cross-linking reactions and then thermal and ageing treatments were performed. According to our results, the main PAE cross-linking reaction occurs by a nucleophilic attack of N atoms in the PAE and/or polyamideamine structures forming 2-propanol bridges between PAE macromolecules. A secondary contribution of ester linkages to the PAE cross-linking was also observed. However, this reaction, which is thermally induced, only occurs under anhydrous conditions. The mechanism related to wet strength development of PAE-based papers was studied by using CMC as a model compound for cellulosic fibres and PAE-CMC interactions as a model for PAE-fibres interactions. Based on results from NMR and FTIR, we clearly showed that PAE react with CMC that is when carboxylic groups are present in great amounts. Consequently, as the number of carboxylic groups present in lignocellulosic fibres is considerably less important and the resulting formed ester bonds are hydrolysable, we postulate that ester bond formation has a negligible impact on the wet strength of PAE-based papers. In the second part of this work, a 100% Eucalyptus pulp suspension was used to prepare PAE-based papers. PAE was added at different dosages (0.4, 0.6 and 1%) into the pulp suspension and its adsorption was indirectly followed by measuring the zeta potential. Results indicate that the adsorption, reconformation and/or penetration phenomena reach an apparent equilibrium between 10 and 30 min. Moreover, we showed that the paper dry strength was not significantly affected by the conductivity level (from 100 to 3000 µS/cm) of the pulp suspension. However, the conductivity has an impact on the wet strength and this effect seems to be enhanced for the highest PAE dosage (1%). We also demonstrated that storing the treated paper under controlled conditions or boosting the PAE cross-linking with a thermal post-treatment does not necessarily lead to the same wet strength. Degrading studies of cross-linked PAE films showed that PAE degradation in a persulfate solution at alkaline medium was more effective. A preliminary study of industrial PAE-based papers (coated and uncoated papers) was also performed. For uncoated paper, persulfate treatment was the most efficient. For coated papers, all treatments were inefficient in the used conditions, although a decrease of the wet tensile force of degraded samples was observed. The main responsible of the decrease of persulfate efficiency for coated papers was probably related to side reactions of free radicals with the coating constituents.

La tesi realitza un estudi detallat dels principals processos que tenen lloc durant l'eliminació de tinta tòner per flotació.L'estudi del procés d'adhesió de tinta a la superfície de bombolles d'aire s'ha realitzat mitjançant visió artificial. Els resultats obtinguts han mostrat que un excés de tensioactiu provoca una disminució de la quantitat de tinta unida a la bombolla d'aire i per tant una disminució de l'eficàcia del procés de flotació. La caracterització de les bombolles d'aire presents en una cel·la de flotació ha posat de manifest que tant el cabal d'aire com la velocitat de l'agitador configuren la distribució de diàmetres final. L'estudi del procés d'eliminació de tinta per flotació en absència de fibres cel·lulòsiques ha mostrat que les variables físico-químiques estudiades són les que tenen una major influència en el procés d'eliminació de tinta tòner per flotació.Finalment s'han addicionat fibres cel·lulòsiques a la suspensió. S'ha pogut comprovar que s'aconsegueix una bona eliminació de tinta sempre i quan les condicions hidrodinàmiques siguin les adequades. / First of all the adhesion of ink particles to air bubbles surface was studied by means of artificial vision. Results obtained showed that an excess of surfactant decreases ink adsorption decreasing flotation efficiency. Air bubbles created in a lab-scale flotation cell were characterized by means of artificial vision. Results showed that air flow and agitation rate configure the final air bubble distribution.Ink removal from a flotation cell was studied without the presence of cellulose fibers. Results obtained showed that the physico-chemical variables studied had a major influence on ink removal than hydrodynamic variables studied.Finally, cellulose fibers were added to the suspension. Results obtained showed that it was possible to obtain good flotation results provided that the hydrodynamic conditions were carefully adjusted.

Le travail présenté dans ce manuscrit s’intéresse au mode d’action des résines thermodurcissables utilisées pour conférer au matériau papier des propriétés spécifiques. En effet, certains papiers sont destinés, au cours de leur usage, à être en contact avec des liquides et en particulier de l’eau. C’est le cas, par exemple, des papiers absorbants, de certains papiers filtres, mais aussi de papiers pour étiquettes ou pour billets de banque. En présence d’eau, les papiers perdent rapidement leur résistance mécanique, essentiellement due à la présence en grand nombre de liaisons hydrogène, d’où la nécessité d’un traitement : l’objectif est de maintenir un certain niveau de résistance des papiers saturés en eau. Ces traitements consistent à introduire dans la suspension fibreuse, en cours d’élaboration, des pré-polymères cationiques s’adsorbant à la surface des fibres. Après la formation de la feuille de papier, la feuille humide est séchée et c’est au cours de cette étape que s’amorce la réticulation de ces polymères. Elle conduit à la formation d’un réseau tridimensionnel de polymère dans le matelas fibreux. Ce réseau permet au papier de conserver ses propriétés mécaniques lorsqu’il est en contact avec de l’eau. Il présente ce que l’on appelle communément une résistance à l’état humide (REH). Un des inconvénients de ce type de traitement est lié aux difficultés de recyclage des papiers obtenus. Il nécessite un traitement particulièrement intensif et coûteux qui couple une action mécanique (désintégration, dépastillage) à une action chimique (utilisation d’hydroxyde de sodium, par exemple). Même si ces produits sont largement utilisés, les mécanismes mis en jeu que ce soit pour le développement des propriétés de REH ou pour le recyclage ne sont pas totalement compris. Dans ce contexte, ce travail a pour objectif d’étudier le mode d’action de pré-polymères de polyamideamine épichlorhydrine (PAE), couramment utilisés en papeterie pour conférer au matériau papier une résistance à l’état humide (REH). Il s’intéresse à la caractérisation de solutions commerciales de PAE et à l’étude des mécanismes réactionnels de ces pré-polymères. Il traite également de l’effet de certains paramètres de production du papier sur l’efficacité des traitements. Enfin, il apporte de éléments nouveaux sur la compréhension de l’étape de recyclage. / Polyamideamine epichlorohydrin (PAE) resin is a water soluble additive and the most used permanent wet strength additive in alkaline conditions for preparing wet strengthened papers. In this thesis, we studied some properties of PAE resins and wet strengthened papers prepared from them. In order to elucidate PAE structure, liquid state, 1H and 13C NMR was performed and permitted signals assignment of PAE structure. PAE films were prepared to study cross-linking reactions and then thermal and ageing treatments were performed. According to our results, the main PAE cross-linking reaction occurs by a nucleophilic attack of N atoms in the PAE and/or polyamideamine structures forming 2-propanol bridges between PAE macromolecules. A secondary contribution of ester linkages to the PAE cross-linking was also observed. However, this reaction, which is thermally induced, only occurs under anhydrous conditions. The mechanism related to wet strength development of PAE-based papers was studied by using CMC as a model compound for cellulosic fibres and PAE-CMC interactions as a model for PAE-fibres interactions. Based on results from NMR and FTIR, we clearly showed that PAE react with CMC that is when carboxylic groups are present in great amounts. Consequently, as the number of carboxylic groups present in lignocellulosic fibres is considerably less important and the resulting formed ester bonds are hydrolysable, we postulate that ester bond formation has a negligible impact on the wet strength of PAE-based papers. In the second part of this work, a 100% Eucalyptus pulp suspension was used to prepare PAE-based papers. PAE was added at different dosages (0.4, 0.6 and 1%) into the pulp suspension and its adsorption was indirectly followed by measuring the zeta potential. Results indicate that the adsorption, reconformation and/or penetration phenomena reach an apparent equilibrium between 10 and 30 min. Moreover, we showed that the paper dry strength was not significantly affected by the conductivity level (from 100 to 3000 µS/cm) of the pulp suspension. However, the conductivity has an impact on the wet strength and this effect seems to be enhanced for the highest PAE dosage (1%). We also demonstrated that storing the treated paper under controlled conditions or boosting the PAE cross-linking with a thermal post-treatment does not necessarily lead to the same wet strength. Degrading studies of cross-linked PAE films showed that PAE degradation in a persulfate solution at alkaline medium was more effective. A preliminary study of industrial PAE-based papers (coated and uncoated papers) was also performed. For uncoated paper, persulfate treatment was the most efficient. For coated papers, all treatments were inefficient in the used conditions, although a decrease of the wet tensile force of degraded samples was observed. The main responsible of the decrease of persulfate efficiency for coated papers was probably related to side reactions of free radicals with the coating constituents.

Participatory Action Research (PAR) was carried out to improve educational practices and environmental sustainability in an International School in Vietnam by undertaking two cycles of PAR to determine how the school community could use paper on a more sustainable basis. The methodology included sorting paper and encouraging the reuse of paper. Practices related to computer printing, report writing and newsletter production were also investigated. Changes in the school community, in terms of accepting responsibility and demonstrating changed attitudes and behaviours, were measured. The school community demonstrated greater awareness, increased responsibility and more action competence. Critical awareness of unsustainable practices increased. Individuals were able to effect change, but it is recommended that such actions should be institutionalised for such changes to be sustainable. Limitations and recommendations emphasise the need for continuing PAR to implement sustainability. / Educational Studies / M. Ed. (Environmental Education)

Participatory Action Research (PAR) was carried out to improve educational practices and environmental sustainability in an International School in Vietnam by undertaking two cycles of PAR to determine how the school community could use paper on a more sustainable basis. The methodology included sorting paper and encouraging the reuse of paper. Practices related to computer printing, report writing and newsletter production were also investigated. Changes in the school community, in terms of accepting responsibility and demonstrating changed attitudes and behaviours, were measured. The school community demonstrated greater awareness, increased responsibility and more action competence. Critical awareness of unsustainable practices increased. Individuals were able to effect change, but it is recommended that such actions should be institutionalised for such changes to be sustainable. Limitations and recommendations emphasise the need for continuing PAR to implement sustainability. / Educational Studies / M. Ed. (Environmental Education)