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

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dc.contributor.authorMakhathini, S. C.en_ZA
dc.date.accessioned2014-09-10T12:33:18Z
dc.date.available2014-09-10T12:33:18Z
dc.date.issued2002en_ZA
dc.descriptionIncludes bibliographical references.en_ZA
dc.description.abstractWorldwide 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.en_ZA
dc.identifier.apacitationMakhathini, S. C. (2002). <i>Environmental consequences associated with ash-stabilisation of organic sludges from the synthol process</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Geological Sciences. Retrieved from http://hdl.handle.net/11427/7403en_ZA
dc.identifier.chicagocitationMakhathini, S. C.. <i>"Environmental consequences associated with ash-stabilisation of organic sludges from the synthol process."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Geological Sciences, 2002. http://hdl.handle.net/11427/7403en_ZA
dc.identifier.citationMakhathini, S. C. 2002. Environmental consequences associated with ash-stabilisation of organic sludges from the synthol process. Thesis. University of Cape Town ,Faculty of Science ,Department of Geological Sciences. http://hdl.handle.net/11427/7403en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Makhathini, S. C. AB - 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. DA - 2002 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2002 T1 - Environmental consequences associated with ash-stabilisation of organic sludges from the synthol process TI - Environmental consequences associated with ash-stabilisation of organic sludges from the synthol process UR - http://hdl.handle.net/11427/7403 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/7403
dc.identifier.vancouvercitationMakhathini S C. Environmental consequences associated with ash-stabilisation of organic sludges from the synthol process. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Geological Sciences, 2002 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/7403en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Geological Sciencesen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherEnvironmental Geochemistryen_ZA
dc.titleEnvironmental consequences associated with ash-stabilisation of organic sludges from the synthol processen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMScen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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