This study evaluates the enhancement of anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW) by microwave pretreatment (MW) at high temperatures (115, 145 and 175°C). The highest level of solubilization was achieved at 175ºC, with a supplemental water addition of 30% (SWA30). Pretreatments combining two modalities; MW heating in presence or absence of hydrogen peroxide (H2O2) was also investigated. Biochemical methane potential (BMP) tests were conducted on the whole OFMSW, as well as on the liquid fractions. The whole OFMSW pretreated at 115 and 145 ºC showed little improvement in biogas production over control. When pretreated at 175 ºC, biogas production decreased due to formation of refractory compounds, inhibiting digestion. For the liquid fraction of OFMSW, the effect of pretreatment on the cumulative biogas production (CBP) was more pronounced for supplemental water addition of 20% (SWA20) at 145 ºC. Combining MW and H2O2 modalities did not have a positive impact on OFMSW stabilization and enhanced biogas production. Based on the BMP assay results, the effects of MW pretreatment (145 ºC) on the AD of OFMSW (SWA20) were further evaluated in single and dual stage semi-continuous digesters at hydraulic retention times (HRTs) of 20, 15, 12 and 9 days. Overall, MW pretreatment did not enhance the AD of the whole waste at the HRTs tested. However, the use of a dual stage reactor digesting non pretreated whole OFMSW had the best performance with the shortest HRT of 9 days. Conversely, for free liquid after pretreatment in two stage reactors at 20 day HRT methane production was tripled. In general, the performance of the dual stage digesters surpassed that of the single stage reactors. Cyclic BMP assays indicated that using an appropriate fraction of recycled effluent leachate can be implemented without negatively effecting methanogenic activity and biogas production. Based on the results obtained in this study, digestion of OFMSW by dual stage reactors without pretreatment appears to provide the best potential for waste stabilization in terms of biogas production and yield, process stability and volumetric loading rates.

Using glycerol from biodiesel production as a fuel in a microbial fuel cell (MFC) will generate electricity and valuable by-products from what is currently considered waste. This research aims to screen E. coli (W3110, TG1, DH5, BL21), P. freudenreichii (subspecies freudenreichii and shermanii), and mixed cultures enriched from compost (AR1, AR2, AR3) as anodic biocatalysts in a glycerol-oxidizing MFC. Anaerobic fermentation experiments were performed to determine the oxidative capacity of each catalyst towards glycerol. Using an optimized medium for each strain, the highest anaerobic glycerol conversion from each group was achieved by E. coli W3110 (4.1 g/L), P. freudenreichii ssp. shermanii (10 g/L), and AR2 (20 g/L). These cultures were then tested in an MFC system. All three catalysts exhibited exoelectrogenicity. The highest power density was achieved using P. freudenreichii ssp. shermanii (14.9 mW m-2), followed by AR2 (11.7 mW m-2), and finally E. coli W3110 (9.8 mW m-2).

Gasification technologies are expected to play a key role in the future of solid waste management since the conversion of municipal and industrial solid wastes to a gaseous fuel significantly increases its value. Municipal solid waste (MSW) gasification for electrical power generation was conducted in a fluidized bed gasifier and the feasibility of using a control system was evaluated to facilitate its management and operation. The performance of an engine using the gas produced was evaluated. A procedure was also tested to upgrade the quality of the gas and optimize its production. The devices installed and automated control system developed was able to achieve and maintain the set conditions for optimum gasification. The most important parameters of reaction temperature and equivalence ratio were fully controlled. Gas production went at a rate of 4.00 kg min-1 with a yield of 2.78 m3 kg-1 of fuel and a heating value (HV) of 7.94 MJ Nm-3. Within the set limits of the tests, the highest production of synthesis gas and the net heating value of 8.97 MJ Nm-3 resulted from gasification at 725°C and ER of 0.25 which was very close to the predicted value of 7.47 MJ Nm-3. This was not affected by temperature but significantly affected by the equivalence ratio. The overall engine-generator efficiency at 7.5 kW electrical power load was lower at 19.81% for gasoline fueled engine compared to 35.27% for synthesis gas. The pressure swing adsorption (PSA) system increased the net heating value of the product gas by an average of 38% gas over that of inlet gas. There were no traces of carbon dioxide in the product gas indicating that it had been completely adsorbed by the system. MSW showed relatively lower fouling and slagging tendencies than cotton gin trash (CGT) and dairy manure (DM). This was further supported by the compressive strength measurements of the ash of MSW, CGT and DM and the EDS elemental analysis of the MSW ash.

Thesis (M.S.)--University of Hawaii at Manoa, 2007. / Includes bibliographical references (leaves 121-127). / xiv, 127 leaves, bound ill. 29 cm

Acid rock drainage (ARD) is recognised as one of the most serious environmental issues currently facing the mining industry. ARD management strategies rely heavily on the ability to measure the ARD potential of waste materials to ensure strategies are appropriate to the ARD risks. It is apparent that improvements to the understanding of ARD test methods and development of methods to better represent the ARD potential of samples will contribute significantly to the value and reliability of ARD assessment. The research described in this thesis focused on critical assessment and improvement of: ARD test methodology; approach to testing; and interpretation of results for coal mine wastes. Kaltim Prima Coal Mine (KPC) in Kalimantan, Indonesia was selected as a case study site to help focus the research, with the understanding that the broad similarities of coal sequences in general would allow broader application of the findings. / Thesis (PhDApSc(MineralsandMaterials))--University of South Australia, 2005.

Thesis (PhD)--University of South Australia, 1998

The project undertaken was aimed at extending a current craft based jewellery practice. Related by structure and materiality, the research sought to develop exploratory shapes as low seating objects to exist within small scale living spaces and studio apartments. Signaling an increased conscious way of thinking and working, a reflective process examining each form as series, provided an incremental creative strategy. The availability of discarded materials suggested possibilities for a sustainable cost effective option as a mode of contemporary practice. This combined approach was considered impact negative, diffusing global waste, and impact positive providing valid alternatives through functional and aesthetic objects. At present waste materials exist as products are still designed and made on the basis of planned obsolescence, thus an exploitation and escalation of global resources and resultant hazardous outcomes continues. Citing selected writings by Victor Papanek, (1992), and Edwin Datschefski, (2006) provided an understanding of the misuse high impact advanced technologies imposes on the environment. These notions were discussed during the project and in relation to contemporary models of practice which currently use discarded materials to make objects for living. Based on a survey observing the local homewares and furniture industries within Sydney, Australia, and recent published material, a niche market was discovered for challenging conventions of low seating objects. Initial sketches were transformed into marquettes then developed into full size prototypes of multi functional forms. a series of forms were scaled up, made of discarded materials using simple hand crafted processes and minimal production methods. As a reference influences included architects, sculptors and craft practitioners who were examined particularly for their use of discarded materials or for their construction methods. During experimental studies visual source material drew upon an observation and analysis of architecture, skeletal structures and land formations. In an exhibition originally titled, "Be Seated", these forms made as initial prototypes were exhibited at Kudos Gallery, Sydney, Australia, during May 2007. They were later refined and renamed as "Low Life" for a group exhibition "Contained" held at Kudos Gallery during 2008.

Acid rock drainage (ARD) is recognised as one of the most serious environmental issues currently facing the mining industry. ARD management strategies rely heavily on the ability to measure the ARD potential of waste materials to ensure strategies are appropriate to the ARD risks. It is apparent that improvements to the understanding of ARD test methods and development of methods to better represent the ARD potential of samples will contribute significantly to the value and reliability of ARD assessment. The research described in this thesis focused on critical assessment and improvement of: ARD test methodology; approach to testing; and interpretation of results for coal mine wastes. Kaltim Prima Coal Mine (KPC) in Kalimantan, Indonesia was selected as a case study site to help focus the research, with the understanding that the broad similarities of coal sequences in general would allow broader application of the findings. / Thesis (PhDApSc(MineralsandMaterials))--University of South Australia, 2005

Acid rock drainage (ARD) is recognised as one of the most serious environmental issues currently facing the mining industry. ARD management strategies rely heavily on the ability to measure the ARD potential of waste materials to ensure strategies are appropriate to the ARD risks. It is apparent that improvements to the understanding of ARD test methods and development of methods to better represent the ARD potential of samples will contribute significantly to the value and reliability of ARD assessment. The research described in this thesis focused on critical assessment and improvement of: ARD test methodology; approach to testing; and interpretation of results for coal mine wastes. Kaltim Prima Coal Mine (KPC) in Kalimantan, Indonesia was selected as a case study site to help focus the research, with the understanding that the broad similarities of coal sequences in general would allow broader application of the findings. / Thesis (PhDApSc(MineralsandMaterials))--University of South Australia, 2005

Use of bauxite refining residue to reduce the mobility of heavy metals in municipal waste compost. Due to the adverse environmental impact of landfills and the lack of space for nearby population centres an unprecedented interest has developed in waste recycling with the objective to reduce the volume of waste disposed. Generally organic matter represents the largest fraction in the domestic waste stream including food, garden and paper waste. In the past efforts have been made to process this organic fraction into muniapal compost.However contamination of the compost with heavy metals has in many cases resulted in the lack of suitable markets and subsequent closure of compost facilities. A study was undertaken and aimed at reducing the concentration and mobility of heavy metals in municipal compost. Bauxite refining residue ha; a high capacity to immobilise metals in soils through precipitation, cation exchange and chemisorption (Fe- and Al- oxides). The first step in the study was to assess the metal adsorption capacity of red mud by equilibrating red mud with metal solutions. Metal removal from solution proved very high. Subsequently, the effect of red mud addition to municipal compost was studied in relation to metal mobility. In particular the interaction of metals with the mobile soluble organic fraction, the humic and fulvic acids, was investigated. It was found that most metals remained in the insoluble humin fraction and the metals in solution remained complexed to the soluble organic fraction. Red mud appeared to be able to adsorp fulvic and humic acids and thus indirectly immobilise the metals in solution. Red mud did not appear to be able to transfer metals from the organic fraction to the mineral red mud fraction. ft was kypothesised that, in order for the metals to be adsorped to red mud, the red mud needed to be present in the organic waste prior to composting. Metal adsorption to red mud is a rapid chemical reaction while metal complexation to the organic fraction takes a number of weeks, since it must be sufficiently oxidised to contain functional groups. In order to verify this hypothesis, an installation with seven incubators was developed which allowed composting to be undertaken under computer controlled conditions and monitored for temperature, airflow and carbon dioxide respiration. The incubators were filled with 10 kg of a mixture of grass clippings and sawdust. The first incubator functioned as a control. The contents of the rest of the incubators were spiked with the following metals: Cd, Cr, Cu, Ni, Pb and Zn. In addition the contents of the 3rd - 7th incubators were amended with an increasing percentage of red mud, respectively 10,20,25,30 and 40 % by weight. After the mixture was composted, the metal mobility was reduced by approx. 80 - 99 %, depending on the metal. The mobility was assessed as leachable and plant available in relation to the total metal content. Red mud did not affect the composting process if < 40% red mud was added. The next step was to compost municipal organic waste in a pilot plant (capacity 5 m3) using batches with and without red mud. Mixed waste was collected from 150 households and the glass, metal and plastic fractions were removed bx- manual sorting. The rest was composted. The red mud - compost had a relatively lower metal content and a reduced metal mobility compared to compost without red mud. The red mud - compost also had a 300 times higher pH buffer capacity and 90%less soluble organic matter. The addition of red mud prior to composting was found to reduce the concentration and mobility of metals in compost, improve the quality of compost as a soil conditioner, increased the resistance of the organic fraction against further breakdown and this process thus adds value to both red mud and organic waste.