Les traitements phytosanitaires intensifs en viticulture, conjugués aux flux de ruissellement, se traduisent par l'arrivée de cuivre dans les bassins d'orage (BO). Des phénomènes de bioatténuation impliquant la microflore et les macrophytes s'observent, mais les niveaux d'épuration sont souvent faibles et variables. La phytoextraction du Cu est une technique intéressante in situ mais sa lenteur la pénalise. La bioaugmentation couplée à la phytoremédiation est une solution pour augmenter la vitesse d'extraction. L'étude a consisté à sélectionner un triplet «bactérie-plante-sorbant » afin d'extraire le Cu du sédiment et de réduire sa teneur dans les eaux en sortie de BO. Les trois composantes ont ensuite été assemblées dans des microcosmes remplis d'un mélange sable-sédiment reproduisant les caractéristiques d'un BO de référence. Sur 564 isolats bactériens cultivables, 84 ont montré une capacité à complexer les métaux et l'isolat n°l06 a été retenu pour sa capacité à complexer le Cu. Des trois macrophytes testés, Phragmites australis, espèce retenue dans la suite de l'étude, a accumulé le plus de Cu dans les parties aériennes. Enfin, la pulpe de betterave s'est révélée être le sorbant le plus efficace dans une matrice complexe et en présence d'herbicides. Des expériences en microcosmes, mettant enjeu le triplet sélectionné, ont été réalisées. La localisation de la pulpe de betterave en sortie de microcosmes a réduit de 20% les quantités de Cu exportées par les eaux en atteignant un abattement de 95%. La phytoextraction du Cu a été augmentée par 1,7 grâce à la bioaugmentation dans le cas d'un régime hydraulique semi-continu et d'une inoculation répétée de l'isolat n°106. / Intensive pesticides use in viticulture combined with runoff often result in amounts of Cu getting to storm basins (SB). Biological pesticide mitigation has been observed and related to the role of natural macrophyte together with their associated microflora. Nevertheless, low and variable mitigation levels are most often reported. Cu phytoextraction is a promising in situ technology but requires time. Bioaugmentation-assisted phytoextraction is a new technology that may enhance the phytoextraction rate. The study consisted in selecting the best "microorganism-plant-sorbent" association in order to extract Cu from sediments and mitigate Cu load in SB outlet waters. The association of these three selected components has been studied in SB-scaled microcosms filled with a sand-sediment mixture to a better understanding of the depollution process feasability. Among the 564 isolates extracted from SB sediments, 84 were able to complex metals and isolate 106 was selected for the process implementation on the base of its ability to complex Cu. On the 3 studied macrophytes, Phragmites australis accumulated more Cu in aerial parts. Finally, sugar beet pulp has been selected as the best Cu sorbant in mixture with herbicides and in a complex matrix. Microcosm experiments that associated the best three components were carried out. Results showed that sugar beet pulp located at the outlet of microcosms reduced significantly (20 %) Cu amounts in outlet waters to reach a mitigation rate of 95%. Cu extraction in aerial parts of P. australis has been improved by a factor of 1,7 thanks to an intermittent wate Joad, with drying and rewetting periods along with repeated inoculations.

Mineralization has the potential to capture CO₂. In nature, mineralization is the chemical weathering of alkaline-earth minerals in which stable carbonate minerals are formed, which leads to the removal of CO₂ from the atmosphere. The adsorptive carbonation reaction of olivine ((Mg,Fe)₂SiO₄)), consisting mainly of pure magnesium silicate (Mg₂SiO₄), a main constituent of the Earth’s crust, was carried out to estimate its potential application to the separation of CO₂ in the presence of water vapor in combustion plumes. Based on the thermodynamics for a basis of the reaction mechanism, the olivine carbonation reaction is thermodynamically favorable. Water vapor was found to play an important role in improving the carbonation rate, and experimental results revealed that carbon dioxide carbon dioxide can bind into olivine minerals to form highly stable surface carbonates. The reaction activity of olivine and pure Mg₂SiO₄ in the presence/absence of water vapor was carried out by varying the temperature, reactant concentrations, and space time. Based on changes in CO₂ concentration with time, the reaction kinetic model of pure Mg₂SiO₄carbonation was developed. The reaction order was found to be approximately 1 for CO₂. The activation energy derived for the Arrhenius equation of Mg₂SiO₄-based carbonation is 76.2 ± 4.8 kJ/mol based on the changes in the reaction rates with temperature in the range of 150-200°C. To investigate the molecular reaction mechanism of CO₂ adsorption on the metal oxide surface, forming carbonates, we performed the quantum mechanical calculation of CO₂ adsorption on a CaO (100) surface. It shows that CO₂ molecules strongly react with the CaO surface due to its high reactivity and high basicity. Consequently, this study will basically lay the groundwork for the chemical mechanism of mineral carbonation of olivine with carbon dioxide in the presence of water vapor and as provide relevant information for the practical application of CO₂ sequestration by stable adsorption on mineral silicates.

Improvement of the efficiency of carbon dioxide (CO2) separation from flue gases has been identified as a high-priority research area to reduce the total energy cost of carbon capture and sequestration technologies in coal-fired power plants. Efficient CO2 removal from flue gases by adsorption systems requires the design of novel sorbents capable of capturing, concentrating and recovering CO2 on a cost-effective basis. The preparation of a novel aminosilane-functionalized cellulosic polymer sorbent by grafting of aminosilanes showed promising performance for CO2 separation and capture. A strategy for the introduction of N-(2-aminoethyl)-3-aminoisobutyldimethylmethoxysilane functionalities into cellulose acetate backbone by anhydrous grafting is described in this study. The dry sorption capacity of the aminosilane-functionalized cellulosic polymer reached 27 cc (STP) CO2/ cc sorbent at 1 atm and 39 cc (STP) CO2/ cc sorbent at 5 atm and 308 K. Exposure to water vapor slightly increased the sorption capacity of the sorbent, suggesting its potential for rapid cyclic adsorption processes under humid feed conditions. In addition, a strategy for the preparation of a cellulose acetate-titanium(IV) oxide sorbent by the reaction of cellulose acetate with titanium tetrachloride is presented. The organic-metal hybrid sorbent presented a sorption capacity of 14 cc (STP) CO2/ cc sorbent at 1 atm and 49 cc (STP) CO2/ cc sorbent at 5 atm and 308 K. The novel CO2 sorbents were characterized in terms of chemical composition, density changes, molecular structure, thermal stability, and surface morphology.

Pipeline natural gas is the primary fuel of choice for distributed fuel cell-based applications. The concentration of sulfur in odorized natural gas is about 30 ppm, with acceptable levels being <1 ppm for catalyst stability in such applications. Packed bed technology for desulfurization suffers from several disadvantages including high pressure drop and slow regeneration rates that require large unit sizes. We describe a novel Rapid Temperature Swing Adsorption (RTSA) system utilizing hollow fibers with polymer 'binder', impregnated with high loadings of sulfur selective sorbent 'fillers'. Steam and cooling water can be utilized to thermally swing the sorbent during the regeneration cycles. An impermeable, thin polymer barrier layer on the outside of fiber sorbents allows only thermal interactions with the regeneration media, thereby promoting consistent sorption capacity over repeated cycles. A simplified flow pattern minimizes pressure drop, porous core morphology maximizes sorption efficiencies, while small fiber dimensions allows for rapid thermal cycles.

Propylene is one of the most important feedstocks of the petrochemical industry with an estimated 2015 worldwide demand of 100 million tons. Retrofitting conventional C3 splitters is highly desirable due to the huge amount of thermal energy required to separate propylene from propane. Membrane separation is among the alternatives that both academia and industry have actively studied during the past decades, however; many challenges remain to advance membrane separation as a scalable technology for energy-efficient propylene/propane separations. The overarching goal of this research is to provide a framework for development of scalable ZIF-based mixed-matrix membrane that is able to deliver attractive transport properties for advanced gas separations. Zeolitic imidazolate frameworks (ZIFs) were pursued instead of conventional molecular sieves (zeolites and carbon molecular sieves) to form mixed-matrix membrane due to their intrinsic compatibility with high Tg glassy polymers. A systematic study of adsorption and diffusion in zeolitic imidazolate framework-8 (ZIF-8) suggests that this material is remarkably kinetically selective for C3 and C4 hydrocarbons and therefore promising for membrane-based gas separation and adsorptive separation. As a result, ZIF-8 was used to form mixed-matrix dense film membranes with polyimide 6FDA-DAM at varied particle loadings and it was found that ZIF-8 significantly enhanced propylene/propane separation performance beyond the “permeability-selectivity” trade-off curve for polymeric materials. Eventually, this research advanced ZIF-based mixed-matrix membrane into a scalable technology by successfully forming high-loading dual-layer ZIF-8/6FDA-DAM asymmetric mixed-matrix hollow fiber membranes with attractive propylene/propane selectivity.

M. Tech. Environmental Management / Investigates the possibility of using maize tassel powder as a solid phase extraction sorbent for the recovery of Ag, Au and Cu from aqueous solution. The surface characteristics of maize tassel and its ability to remove Ag, Au and Cu from aqueous solutions needed to be established before the preparation of maize tassel beads.

The capacity of four mineral sorbents to retain arsenic under simulated mature landfill conditions was tested using semi-batch and continuous flow columns. The sorbents tested were Fe-, Ti-, La-, and Zr- based oxi(hydroxides). The Fe sorbent was included as a positive control to compare the release of As from a substrate subject to reduction to those of the, non-sensitive to reduction under typical mature landfill conditions, Ti, La, and Zr media. It has been proved that under mature landfill conditions, As(V) preloaded on ferric sorbents is prompt to be released at high levels. Our results indicate that Ti, La, and Zr sorbents can release As at a similar or higher degree than a ferric sorbent. In a second phase, the capacity of the same sorbents to retain As was evaluated after being subject to polymeric encapsulation in an epoxic resin. Landfill conditions were simulated by use of semi-batch column systems packed with compost and fed with actual landfill leachate. Results obtained indicated that encapsulation highly enhanced As retention of the media under simulated landfill conditions. In our research regarding soil contamination by atmospheric transport from mine tailings, a previously developed deposition forecasting model (DFM) that is designed to model the transport of particulate As and Pb from mine tailing impoundments is verified using dust collection and topsoil measurements. The forecast deposition patterns are compared to dust collected by inverted-disc samplers through gravimetric, chemical composition and lead isotopic analysis. The DFM is capable of predicting dust deposition patterns from the tailings impoundment to the surrounding area. Finally, the bioaccessibility of As and Pb were on samples collected at Iron King Mine Tailing was evaluated through chemical extractions using simulated the gastric and the lung fluids of the human body. Results obtained indicate that extractions using simulated gastric fluid lead to As concentrations one order of magnitude higher to those obtained with lung fluid. For Pb concentration the difference was greater than 2 orders of magnitude.

The pollution by heavy metals in the roadside soil alteration tendency was thoroughly investigated by applying the complex experimental and statistical environmental analysis and means for pollution by heavy metals and petroleum products reduction by natural zeolite and vermiculite were evaluated and developed. To reach the novelty it was: • The roadside soil pollution by heavy metals, it’s dangerous and pollution variation tendencies were investigated. • The suitability of natural zeolite for heavy metal removal from soil and aquatic solutions was proved. • The suitability of natural zeolite and vermiculite for petroleum products removal from aquatic solutions was proved.

The research presented in this thesis entailed an investigation of heavy metal uptake by Palmaria palmata, a red marine alga. The alga was dry and organically certified. The heavy metals of interest were those commonly found in the wastewaters of the printed wiring board industry, namely Cu2+Pb2+, Cd2+, Zn 2+ and Ni2+. The ultimate objective of the work was to determine whether or not the factors expected to influence the metal uptake to the greatest extent could be optimized within functional ranges, leading eventually to process design (beyond the scope of this thesis). These factors were pH, temperature, initial concentration of metal in aqueous solution, and contact time. A number of preliminary experiments were performed to establish a basis for the design of the optimization studies. / Although it was not possible to adequately define optimal regions of operation for the biosorption of heavy metals by Palmaria palmata , general trends were elucidated, and the limitations of the methodology used were clarified. (Abstract shortened by UMI.)

Thesis (Ph. D.)--Auburn University. / Abstract. Vita. Includes bibliographical references (p. 162-171).