The phenomenon of selective retention of cations from aqueous solutions by microbial biomass has been termed biosorption. Samples of waste microbial biomass, originating from industrial fermentations and biological waste water treatment plants, have been tested for their uranium and thorium biosorption potential. Optimum biosorption conditions have been identified. Rhizopus arrhizus was identified as the biomass presenting the highest U or Th uptake capacity, in excess of 170 mg/g. The effect of solution co-ions (namely Fe('+2), Zn('+2)) on the equilibrium biosorptive uptake capacity of Rhizopus arrhizus has been examined. The study of the rapid kinetics of U and Th biosorption has been initiated. Accumulated experimental and theoretical information led to the formulation of a biosorption mechanism hypothesis for the systems U or Th - Rhizopus arrhizus. Biosorption of both U and Th by Rhizopus arrhizus occurs mainly in the cell wall of the mycelium. Complexation by the cell wall chitin, adsorption, and hydrolysis of the complex are the processes participating in the proposed mechanism hypotheses.

This thesis presents some novel techniques to process Post Consumer Carpet waste and provides detailed cost comparisons between setting up and running small-scale decentralized units and large-scale centralized chemical facilities. The techniques presented include: a decentralized underlay manufacturing process which does not distinguish between the types of face fiber, a decentralized facility with twin screw extruder to depolymerize nylon 6 face fiber with a concurrent underlay manufacturing facility, a decentralized pallet production facility, and a centralized facility for chemically depolymerizing nylon 6, and nylon 6,6 with a concurrent underlay manufacturing facility The limiting factors to recycling are the collection of significant volumes of material and effective recycling techniques. This is illustrated in this study. The aim of this study is to enable recyclers to assess their recycling activities using various performance parameters, such as payback period of the venture, mass of carpet recycled, and energy used. Thus, this study aims to shed light on the impact of recycling on current carpet consumption per capita. The results indicate that decentralized facilities located in metropolitan areas with populations of over 2 million people have a lower payback period than the large scale centralized facilities that are sparsely distributed throughout the country. These decentralized facilities are also more efficient in reducing the current carpet consumption per capita. The reduced traveling distance for the post consumer carpet from the collection/disposal site to the processing facility should make a huge impact on energy consumption and the corresponding environmental emissions.

This study examines composite materials prepared from ground recycled tires (tire crumb) and post-consumer recycled high density polyethylene (HDPE). An initial set of composites was prepared from as-received tire crumb and HDPE recyclate containing 040% tire crumb in 10% increments, using injection moulding. The elastic modulus and tensile strength were found to decrease linearly with increasing tire crumb content. Addition of tire crumb to recycled HDPE caused produced an immediate reduction in the strain to failure with a progressively more modest decrease as the tire crumb content was increased. The impact toughness decreased more linearly with increasing tire crumb fraction. Cross sections of the composites showed that the tire crumb particles were in intimate contact with the matrix but post mortem examination of the fracture surface of the impact test specimens indicated that the level of bonding had been poor. A second set of composites was a prepared from 10% tire crumb. The tire crumb was first given an oxidative treatment in hot aqueous copper chloride at concentrations from 0-5 wt% Cu Ch at 50 or 100??C for 6 or 12 hours. The composites were injection moulded with an addition of 0.5 wt% dicumyl peroxide (DCP). These composites showed good bonding between the tire crumb and the recycled HDPE even at concentrations of 0% of the Cu 2+ oxidation catalyst. The addition of DCP was found to substantially reduce the modulus of neat HDPE and this reduction was reflected in the modulus of the composites. It was found that the DCP concentration could be reduced to 0.02% without adversely affecting the composites.

Thesis (Ph. D.)--Michigan State University. Dept. of Agricultural Economics, 2008. / Title from PDF t.p. (viewed July 31, 2009). Includes bibliographical references. Also issued in print.

Thesis (M.P.A.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 101-110).

Thesis (M.P.A.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 101-110). Also available in print.

Thesis (Ph. D.)--Illinois State University, 2002. / Title from title page screen, viewed February 21, 2006. Dissertation Committee: Edward R. Hines (chair), Phyllis McCluskey-Titus, Kenneth H. Strand, Sandra L. Little. Includes bibliographical references (leaves 159-166) and abstract. Also available in print.

Thesis (Ph. D.)--Illinois State University, 1995. / Title from title page screen, viewed April 21, 2006. Dissertation Committee: Edward R. Hines (chair), Floyd B. Hoetling, Kenneth H. Strand, Lemuel W. Watson. Includes bibliographical references (leaves 139-149) and abstract. Also available in print.

Thesis (BTech (Surface Design))Cape Peninsula University of Technology, 2010 / The purpose of this research is to explore and create an understanding of how architectural structures. that adhere to deconstructivist design principles, can inspire the reconstruction of second-hand school fumiture and scrap metal. The planned pieces will continue to create an awareness of sustainability, by designing for reuse. These functional fumiture pieces of low tables and chairs will be handcrafted, appealing to a niche market, or specific spaces and they will act as expressions of contradiction. This research will act as an addition to a body of knowledge, where I will primarily focus on contradicting the traditional form and aesthetic of furniture design. I have decided to create these functional pieces to express a new possible direction of furniture design. The study context is a potential confrontational experience in that I want to challenge the conventional form and aesthetics of fumiture design. These pieces of fumiture will be placed in a niche market where they will exist as one-offs that are not produced for mass-consumption, as they will be individually hand-erafted. These days more and more people are attempting to live in a more sustainable manner by practicing to reduce our consumption of products and resources; reuse that which we have disposed of and forgotten as consumers and to recycle waste products and transform them into a feasible afterlife (Martin, 2010). The theory is focused on Sohaill Inayatullah's theory of "Futures Thinking", and this .theory is further supported by Victor Margolin's study of changing existing situations into preferred ones. The research further reflects on Jacques Derrida's theory of deconstruction, and this research is further supported by the theory of sustainability, by designing for reuse, with a focus on Ezio Manzini. Therefore, my research study is concerned with confronting and challenging the conformity that the form of furniture and its aesthetic adhere to.

Hydrocracking of plastic wastes offers the best value in terms of quality of its process oil product among other feedstock recycling methods capable of recycling mixed plastic waste; a paraffin-rich synthetic crude similar in composition to gasoline and diesel is produced. Additional benefits of the process include heteroatom removal, catalyst conservation as well as a lower process temperature. However PVC content in mixed plastics waste and the high viscosity of plastics are prominent issues in relation to subjecting plastics to petrochemical processes such as hydrocracking. A 5ppm chlorine limit and maximum feedstock viscosity of 0.5 Pas at 200oC is tolerable in the petrochemical industry. Although dechlorination of mixed plastic waste has been studied exhaustively, viscosity studies in relation to process improvement or efficiency in the pyrolysis or hydrocracking of plastics haven’t received as much attention. Viscosity has been identified as being inhibitive to heat and mass transfer, and transport into reactors, as well as being a major problem in relation to designing reactors for feedstock recycling. In this research, four of the main polymer types; high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), Polypropylene (PP), Polystyrene (PS) and Polyethylene Terephthalate (PET) were rheological characterised to establish the extent to which they exceed the recommended viscosity in the petroleum industry. Viscosities 400 – 1200 times the feedstock viscosity in the petrochemical industry at a shear rate of 500s-1, which is typical for pumping and atomisation operations, were obtained during the characterisation of the plastic samples in a conventional capillary rheometer. Saturated chain hydrocarbon solvents (iso-octane, decane, tetradecane, pentadecane and hexadecane) were investigated for treating HDPE, in a range of HDPE-solvent mixtures, in order to reduce its viscosity. Preliminary results of differential scanning calorimetry tests carried out on the solvent-treated HDPE revealed a 12 – 16% drop in the melting peak temperature of the pure HDPE (129 oC) using tetradecane (108 oC), pentadecane (110 oC) and hexadecane (113 oC) for the 20:80 PE-solvent mixtures. iso-octane and decane however only produced a viscosity drop of 3% and 4% respectively for the same 20:80 PE-solvent mixtures. Thermal stability of HDPE was largely unaffected by the solvent treatment except in the case of pentadecane which showed a reducing trend on the decomposition onset temperature as solvent concentration in the starting mixtures was increased, albeit marginal (from 441oC to 437oC). A custom built sealed-vessel impeller viscometer designed to facilitate the treatment of the HDPE via solvent refluxing and in situ viscosity measurement was calibrated by determining constants which enable the conversion of machine data to viscosity and shear rate using Newtonian and non-Newtonian calibration fluids. These constants, the shape factor and shear rate conversion factor, were determined to be 81.03 and 22.08, respectively, with corresponding 95% confidence limits of 79.21 and 86.26, and 21.47 and 24.00. Viscosity measurements of a 40:60 PE-nC15 mixture carried out in the sealed-vessel impeller viscometer at a shear rate of between 71s-1 and 80s-1 at 95% confidence level and 250oC was 7 Pas representing approximately 200 fold reduction from the virgin HDPE measured in the conventional capillary rheometer.