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Environmental consequences associated with ash-stabilisation of organic sludges from the synthol process

Includes bibliographical references.

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Main Author: Makhathini, S. C.
Format: Thesis
Language:English
Published: Department of Geological Sciences 2014
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access_status_str Open Access
author Makhathini, S. C.
author_browse Makhathini, S. C.
author_facet Makhathini, S. C.
author_sort Makhathini, S. C.
collection Thesis
description Includes bibliographical references.
format Thesis
id oai:open.uct.ac.za:11427/7403
institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:52:06.403Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2014
publishDateRange 2014
publishDateSort 2014
publisher Department of Geological Sciences
publisherStr Department of Geological Sciences
record_format dspace
source_str UCTD — University of Cape Town Open Access Repository
spelling oai:open.uct.ac.za:11427/7403 Environmental consequences associated with ash-stabilisation of organic sludges from the synthol process Makhathini, S. C. Environmental Geochemistry Includes bibliographical references. Worldwide increases in environmental awareness have led to the development of new innovative technologies aimed at site remediation and hazardous waste treatment. Solidification/Stabilisation (S/S) is one of such technologies and it has emerged as an environmentally acceptable treatment option for hazardous waste. Initially applied to inorganic wastes, S/S is now being investigated for the treatment of organic wastes and sludges. Challenges facing this venture into the SIS of organic wastes include the lack of technical information on waste-binder interactions, the uncertainty regarding an appropriate method to evaluate the performance of CPS systems, as well as evaluation of the long-term stability of stabilised material. This paper attempts to expand the understanding of chemical and micro-structural waste-binder interactions. Also addressed is the weathering behaviour of stabilised/ solidified organic waste when exposed to two different leaching media, distilled water and the US EPA's Toxicity Characteristic Leaching Procedure (TCLP) solution. Addressed to a minor extent is the effect of stabilised/solidified organic waste on biomass production of sweetcorn maize. The focus in this study was the stabilisation of the synthol sludge (synthol gunk) using a pozzolan system. This was done by preparing stabilised waste forms from synthol gunk and fine ash (ash obtained from the slimes dams, hence has hydrated to some extent). A particle size fraction less than 2 mm of these waste forms were leached with the two leaching solutions. Some of the material was pressed into pellets, which were subsequently leached in the same leaching solutions. The pellets were analysed under SEM-EDS for micro-structural analysis. In a separate set of experiments fine ash, synthol gunk and the stabilised waste forms were mixed with soil in the range 0% to 30% waste addition, after which sweetcorn maize was planted to study the effects on biomass production. Other instrumental techniques used in this study include WDXRF, ICP-MS, FTIR, IC as well as the analysis of dissolved organic carbon (DOC). The study showed that the trace metal speciation of the pozzolanic binder is affected by the presence of the organic waste, with a possible threat of turning the binder into a hazardous material. Elements that were leachable by TCLP on the stabilised product include B, Mn, Ni, Fe, and Br. The addition of lime in the system appears to lower the leachability of B, Mn, and Br while worsening the leachability of Fe, Ba, and Zn. However, addition of lime increases the leachability of B, Cr, Mn, Fe and Br in distilled water. The most likely source of B, Fe, Br and Ba is fine ash. Plant growth studies showed that the toxicity threshold of synthol gunk in the stabilised material on biomass production appears to be lowered from about 2.5% in unstabilised synthol gunk to about 1.2% either due to synergy or the additive effect of ash and synthol gunk. Furthermore, it is likely that some of the toxicity of synthol gunk is due to the hydrophobic coating of roots resulting in inadequate water intake by the plant. 2014-09-10T12:33:18Z 2014-09-10T12:33:18Z 2002 Master Thesis Masters MSc http://hdl.handle.net/11427/7403 eng application/pdf Department of Geological Sciences Faculty of Science University of Cape Town
spellingShingle Environmental Geochemistry
Makhathini, S. C.
Environmental consequences associated with ash-stabilisation of organic sludges from the synthol process
thesis_degree_str Master's
title Environmental consequences associated with ash-stabilisation of organic sludges from the synthol process
title_full Environmental consequences associated with ash-stabilisation of organic sludges from the synthol process
title_fullStr Environmental consequences associated with ash-stabilisation of organic sludges from the synthol process
title_full_unstemmed Environmental consequences associated with ash-stabilisation of organic sludges from the synthol process
title_short Environmental consequences associated with ash-stabilisation of organic sludges from the synthol process
title_sort environmental consequences associated with ash stabilisation of organic sludges from the synthol process
topic Environmental Geochemistry
url http://hdl.handle.net/11427/7403
work_keys_str_mv AT makhathinisc environmentalconsequencesassociatedwithashstabilisationoforganicsludgesfromthesyntholprocess