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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

A macroinvertebrate study of the Shenango River Westinghouse Superfund site, Sharon, PA /

Robinette, Paul R. January 2009 (has links)
Thesis (M.S.)--Youngstown State University, 2009. / Includes bibliographical references (leaves 30-31). Also available via the World Wide Web in PDF format.
22

An Evaluation Study Of The Effectiveness Of Using A Reaction-based Process For Hydrazine Waste Remediation

Oropeza, Cristina M 01 January 2011 (has links)
Hydrazine (HZ) and monomethylhydrazine (MMH) are used extensively as hypergolic propellants at Kennedy Space Center. These highly reactive fuels are considered highly toxic, and potentially carcinogenic. Consequently, the transport, handling, and disposal of hydrazines is strictly regulated to protect personnel and the environment. Currently, KSC generates large volumes of hydrazine-laden wastewater for disposal. This waste is contained and shipped on public highways for subsequent disposal by incineration presenting a potentially catastrophic threat to the environment and the general public in the event of an accidental release. Other existing remediation methods include oxidative and reductive pathways as well as biodegradation in fixed film reactors. Each of these methods has associated drawbacks and limitations that make them unsuitable for industrial use. Recently, hydrazine neutralization by reaction with alpha-ketoglutaric acid (AKGA) to form the stabilized pyridazine derivatives PCA and mPCA has been explored. The applicability of this technique for use at KSC has been established and procedural considerations for implementation have been addressed. Experimental evidence based on worst case scenario decontamination processing simulations and reaction characterization has suggested that AKGA can cost effectively function as a drop-in replacement for current neutralizers with minimal modification to existing infrastructure and operating procedures. Further work will be necessary to satisfy permitting iv requirements and verify that the reaction product stream is non-hazardous in light of limited toxicity data.
23

Determination, mobilization and dechlorination of polychlorinated biphenyl (PCB) compounds in contaminated soils

Wu, Qixiang January 2001 (has links)
No description available.
24

Landscapes in transition: a holistic approach to re-mediating social, economic and environmental ecologies disfigured by mining

Liechti, Matthew Hans January 2017 (has links)
Thesis is submitted in partial fulfilment for the degree of Master of Architecture (Professional) to the Faculty of Engineering and the Built Environment, School of Architecture and Planning at the University of the Witwatersrand, Johannesburg, 2017 / The memories associated with mining are vastly contrasting; ranging from nostalgic recollections of the fortune on which Johannesburg was built to the torturous conditions the miners had to endure both above and below the surface. The essay by the author entitled “Memory retention and cessation in the historical and present context of South Africa and abroad” aims to engage with critically, and explore, the field of memory in relation to mining and broader issues. It is of great importance when establishing a heritage project that the people who engage with it must be able to do so without causing distress or emotional anguish. Can a contextually relevant space be created for the housing and display of such memories? This research report views remediation through a holistic lens that is an approach to the project in its entirety. Remediation is viewed as an approach to solving the fractured nature of Benoni, separated by mining and Apartheid planning, creating ‘buffer zones’ between previously racially orientated areas. The site is a previous ‘buffer zone’ and has not changed its function since it was constructed in 1888. The toxic, disused land offers an opportunity to reclaim what industry has taken away from ‘nature’. Can this ‘buffer zone’ be activated to connect the segregated suburbs of Benoni further? Remediation will also be used as a vehicle for the regeneration of the site, with the aim to return it to a similar ecological state as it was before the mining industry began to alter it. The site has been scarred by the mining industry for over 128 years, polluting both the surface and the sub-surface environment. Can the effects of the temporary environmental degradation be neutralised? The reprocessing of the mine dump has initiated the remediation process, removing around 40 million tonnes of waste (“Transvaal Has Largest Dam In the World” 1950, Vol 56, No. 15 731) from the site, re-mining it, and sending the waste to selected dump sites across the Rand. The Remediation of Acid Mine Drainage (AMD) will reduce the associated noxious effects on the local biosphere, induce a ripple effect further downstream the Blekboskpruit and further on towards the Vaal Dam, where we obtain our drinking water. This example of passive AMD remediation aims to stand as a watershed project that may be adopted and adapted at other sites with similar needs. Is the use of a low-tech, passive wetland system appropriate for AMD remediation and the site? This project aims to be a cultural precinct to objectively display the history of mining in Johannesburg. It does so while being a functioning centre for AMD remediation, in pursuit of solutions for the damage that our mining legacy has had on the landscape and the environment. The Urban Mining facility seeks to create a flagship electronic waste (e-waste) recycling centre that will not only have a positive impact on the local environment but reduce the amount of e-waste being transported illegally to developing countries around the world. Keywords: Acid Mine Drainage, Urban Mining, Remediation, Mining Museum, Benoni / GR2017
25

A critical analysis of how Independent Power Producers (IPP’s) can help to secure a sustainable future for post-mining towns in South Africa through new models of architectural practices, to promote the renewal of architecture as a means of creating new realities and being drivers of sustainable change

Harrison, Peter Carleton January 2018 (has links)
Thesis is submitted in partial fulfilment for the degree of Master of Architecture to the Faculty of Engineering and the Built Environment, School of Architecture and Planning at the University of the Witwatersrand, Johannesburg, 2018 / This thesis aims to understand the role that Independent Power Producers (IPP’s) can play in the renewal of architectural firms in creating new realities and how these firms can once again become drivers of social change. Kathu (Northern Cape), a steel mining town, is facing the reality that it will have to survive without a mining house and the community funding that results from its operations soon. There are three IPP’s within a 50km radius of Kathu. Under the current funding structure all 3 IPP’s have to contribute to socio-economic development (SED) and enterprise development (ED) within Kathu. According to the Independent Power Producers Procurement Programme (IPPP’s), IPP’s are required to provide 1% of gross turnover to community funds for SED and ED development programmes. Where this funding differs from funding obtained from mining houses is that renewable energy is effectively limitless. Despite IPP’s having a projected lifespan of 20 years they will continue to be redeveloped and upgraded. These upgrades will allow for longevity of revenue, which in turn allows for sustained support for the communities surrounding them. Funding structures that are being used to disseminate mining house funds to the communities are suffering from governance issues. This means that the communities do not receive the most effective or necessary forms of development. Through a new typology of architectural practice, the way these funds are managed and utilised can create better environments for those communities. This new typology of architectural firm must move away from the corporate and profit driven nature of modern architectural firms and more towards a ‘Rural Studio’ model. This is where the primary focus is on the community and how to best serve the needs of the people. In doing so SED projects would be more effective in bringing about social change, creating new realities for communities and drivers of sustainability in post-mining towns in South Africa. / XL2019
26

Success factors for urban brownfield redevelopments in South Africa

Goosen, Johan Jacobus January 2017 (has links)
A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering, Johannesburg 2017 / This research sought to identify the key success factors associated with industrial brownfields site redevelopment projects in urban areas of South Africa. Nine such success factors were identified from international and local literature. Through documentary research, three brownfield case studies in Johannesburg were investigated. These included the Newtown Cultural Precinct, the Egoli Gas site and the AECI Modderfontein site. Commonalities includes location within the urban edge, original industrial land use, and the redevelopment intent of the landowners. Aspects differing among the sites include distance from the inner city, size, the certainty of contamination and redevelopment success. Based on the findings of the three case studies, the nine success factors were refined. The factors are no or low contamination, brownfields policy maturity, certainty regarding liability for remediation, risk-based land use options, favourable market conditions, quick funding access with rapid statutory approvals, readily available municipal services and transport infrastructure, and strong political and community support. The case study findings provide indications towards generalisation for success factors that may apply to future brownfields projects. Further research required includes a larger database of brownfields redevelopment case studies to be developed for South African, in order to further test associated success factors. / XL2018
27

Degradation of PCP by laccases of the white-rot fungus Trametes sp. HR577 : a thesis presented in partial fulfilment of the degree of Doctor of Philosophy in Chemistry at Massey University, Palmerston North, New Zealand

Guthrie, Jenness Margaret Unknown Date (has links)
Pentachlorophenol (PCP) is a biocide used by the NZ forestry industry until 1988. Its use was discontinued due to its toxicity to humans and animals. White-rot fungi have been shown to degrade PCP in laboratory and field trials. New Zealand native white-rot fungi were screened to identify organisms suitable for the clean up of PCP contaminated sites. Four criteria were used for the screening: fungal growth at different temperatures, PCP and creosote resistance and PCP degradation in standard liquid medium. Twenty isolates were identified as potentially useful from over 200 that were screened. One unique isolate, Trametes sp. HR577, was chosen for intensive study because it produced the well known laccases previously described from other PCP-degrading white-rot fungi. The white-rot isolate HR577 was assigned to the genus Trametes based on morphological characteristics and gene sequencing studies. The latter showed that the partial laccase gene sequences from Trametes sp. HR 577 had high sequence homology to laccases from other Trametes species, especially T. versicolor and T. villosa. Two laccase isozymes, designated L1c and L2, were purified from Trametes sp. HR577. These isozymes had similar biological properties to other Trametes species laccase isozymes. Both isozymes had a relatively high temperature optima, however, they were not very stable at elevated temperature. The dependence of laccase on dissolved oxygen for catalysis was demonstrated for isozyme L2. Laccase activity was severely inhibited in the absence of dissolved oxygen. This could be restored by reoxygenation into the assay system. Whole cultures of Trametes sp. HR577 grown in liquid culture removed up to 76% of PCP after 72 hours. PCP removal was mostly due to degradation rather than adsorption of PCP to fungal mycelium. Addition of purified and crude laccase isozymes (100 U mL-1) did not enhance PCP degradation. 6-15% of PCP was removed from solutions containing solely purified isozyme L1c or L2 in acetate buffer over 72 hours. Addition of ethanol or the laccase mediator compound 2,2' azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) resulted in increased PCP disappearance from purified laccase cultures. These studies show that the white-rot Trametes sp. HR577 has potential to be used for the clean up of PCP contaminated sites in NZ.
28

Comparison of indigenous and bioaugmented butane and propane-utilizers for transforming 1,1,1-trichloroethane in Moffett Field microcosms

Jitnuyanont, Pardi 12 December 1997 (has links)
Graduation date: 1998
29

Toxic politics at 64N, 171W : addressing military contaminants on St. Lawrence Island, Alaska /

Henifin, Kai A. January 1900 (has links)
Thesis (M.A.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 81-87). Also available on the World Wide Web.
30

The evaluation of the Chemchar, Chemchar II, and Chemchar III gasification processes for the treatment of a variety of inorganic and organic laden wastes

Garrison, Kenneth E. January 2000 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

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