The remediation of sites contaminated by dense non-aqueous phase liquids
(DNAPLs) continues to present a significant environmental challenge globally.
Contributing to this challenge is the difficulty in locating source zones due to local
heterogeneities in the sub-surface. Heterogeneities are significant in fracture rock
environments, such as those found in South Africa, which together with the fluid
properties determine the fate and transport of DNAPLs.
This research is based on evaluating the effectiveness of combining traditional and
novel source zone characterisation methodologies in order to delineate chlorinated
hydrocarbon DNAPLs in a fractured rock environment. The research documents and
evaluates the characterisation process followed in the application of various
methodologies to an Investigation Site in South Africa. A site-specific conceptual site
model is presented indicating the delineation of the multiple chlorinated hydrocarbon
DNAPL source zones at the site. Additionally, a DNAPL source characterisation
approach is proposed for application in fractured rock environments. This approach
allows for the convergence of traditional approaches (such as drilling within a fixed
grid) with more novel approaches (such as high resolution sampling and analysis).
The pioneering use of ribbon NAPL samplers (FLUTeTM activated carbon technology
membranes) in South Africa is documented in this research. In situ source zone
characterisation using this technology in a fractured rock environment is shown to be
successful in determining depth discrete fracture transmissivities and residual
DNAPL zones that would have gone unobserved through methods such as direct
observation and testing rock cores with hydrophobic dyes. The efficiency of this
technology renders it ideal for future continued use in South Africa.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ufs/oai:etd.uovs.ac.za:etd-07172013-154709 |
| Date | 17 July 2013 |
| Creators | Hulley, Vierah |
| Contributors | Prof KT Witthüser |
| Publisher | University of the Free State |
| Source Sets | South African National ETD Portal |
| Language | en-uk |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.uovs.ac.za//theses/available/etd-07172013-154709/restricted/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University Free State or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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