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You searched for +publisher:"University of the Western Cape" +contributor:("Akinyeye, Richard Odunayo"). Showing records 1 – 2 of 2 total matches.

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University of the Western Cape

1. Ndayambaje, Guillaume. Sorption properties of natural zeolites for the removal of ammonium and chromium ions in aqueous solution .

Degree: 2011, University of the Western Cape

There are huge amount of natural clinoptilolite available in South Africa which can be utilised for wastewater treatment of ammonia and chromium if their characteristics are properly known. However, these deposits have not been well characterised but in this study, the untreated clinoptilolite materials were fully characterised using techniques such as SEM-EDS, HRTEM-SAED, XRD, XRF, FTIR and BET. After acid pretreatment with several extractions, the pretreated samples were again characterised using the above mentioned techniques. These pretreated materials were used for NH₄⁺ and Cr³⁺ adsorption of wastewater. The three natural South African clinoptilolite samples used in this study were from ECCA Holdings (ESC and EHC samples) and Pratley (PC sample) deposits obtained from Western Cape and KwaZulu-Natal Province respectively. This study revealed that the chemical composition and mineral phases of South African clinoptilolites vary considerably from site to site, even clinoptilolite mined from the same deposit sites. The XRD analyses showed that Pratley clinoptilolite (PC) was the most pure clinoptilolite sample (81.41 %) compared to the purity of EHC (67.88 %) and ESC (44.0 %) sample. The ECCA Holdings untreated clinoptilolite samples contained dense phases such as quartz which was not found in Pratley sample. Quartz was found to be the most dominant impurity in both ECCA Holding sample. The cation exchange capacity (CEC) of ESC, EHC and PC samples were found to be 1.23, 1.81 and 2.90 meq/g respectively and these results were compared to that of XRF analyses. The acid solutions of 0.02 and 1.0 M HCl were used to pretreat natural clinoptilolite to determine the optimum acid concentration and number of extractions required to fully replace the exchangeable cations. The pretreatment results showed that 0.02 M HCl was the optimum acid concentration for acid pretreatment of clinoptilolite samples. Between 7 and 22 extractions were required to remove Na⁺, K⁺, Ca²⁺ and Mg²⁺ without causing much dealumination of the framework. Sodium ion was found to be weakly bound cation in the clinoptilolite framework, since it could be completely exchanged by H⁺ after 7 extractions with 0.02 M HCl acid solution. Potassium ion was found to be strongly bound in the clinoptilolite framework since it could not be completely exchanged during the acid pretreatment process even after 22 extractions. The HRTEM-SAED and BET results showed that ESC, EHC and PC were all polycrystalline and microporous materials respectively. It was found that the adsorption capacity of the treated Pratley clinoptilolite sample was increased by 36 % for NH₄⁺ removal, compared to that of the untreated PC sample. The adsorption study results showed that the pretreatment of clinoptilolite samples using 150 mL volumes of 0.02 M HCl with 7 acid extractions at 25 °C for ESC pretreated and EHC pretreated. The pretreatment of PC sample at 22 extractions could remove high percentage of NH₄⁺ (98.11 %) within a short contact time of 10 min. The pretreated Pratley… Advisors/Committee Members: Petrik, Leslie F (advisor), Van Der Walt, T.N (advisor), Akinyeye, Richard Odunayo (advisor).

Subjects/Keywords: Adsorption; Cation exchange capacity; Kinetics; Ion exchange; Freundlich isotherm; Zeolites

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Ndayambaje, G. (2011). Sorption properties of natural zeolites for the removal of ammonium and chromium ions in aqueous solution . (Thesis). University of the Western Cape. Retrieved from http://hdl.handle.net/11394/5425

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Ndayambaje, Guillaume. “Sorption properties of natural zeolites for the removal of ammonium and chromium ions in aqueous solution .” 2011. Thesis, University of the Western Cape. Accessed April 10, 2020. http://hdl.handle.net/11394/5425.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Ndayambaje, Guillaume. “Sorption properties of natural zeolites for the removal of ammonium and chromium ions in aqueous solution .” 2011. Web. 10 Apr 2020.

Vancouver:

Ndayambaje G. Sorption properties of natural zeolites for the removal of ammonium and chromium ions in aqueous solution . [Internet] [Thesis]. University of the Western Cape; 2011. [cited 2020 Apr 10]. Available from: http://hdl.handle.net/11394/5425.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Ndayambaje G. Sorption properties of natural zeolites for the removal of ammonium and chromium ions in aqueous solution . [Thesis]. University of the Western Cape; 2011. Available from: http://hdl.handle.net/11394/5425

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


University of the Western Cape

2. Nyale, Sammy Mwasaha. Chemical, physical and morphological changes in weathered brine slurried coal fly ash .

Degree: 2011, University of the Western Cape

Energy production from coal comes with an environmental cost because of the toxic waste produced during coal combustion such as coal ash and brine which are potential water and soil pollutants. Coal ash and brine contain toxic elements which can leach and contaminate soils and ground water if not properly disposed. This study investigated the mobility of species in coal fly ash co-disposed with brine at Sasol Secunda power station in order to establish if the ash dam could act as a salt sink. The ash was dumped as a slurry with 5:1 brine/ash ratio and the dam was in operation for 20 years. It was hypothesized that the disposed Secunda fly ash was capable of leaching toxic metal elements into the surrounding soils and ground water and therefore could not be used as a long term sustainable salt sink. Weathered fly ash samples were collected along a 51 m depth core at the Secunda ash dam by drilling and sampling the ash at 1.5 m depth intervals. A fresh fly ash sample was collected from the hoppers in the ash collection system at the power station. Characterization of both Secunda fresh ash and Secunda weathered ash core samples was done using X-ray diffraction (XRD) for mineralogy, X-ray fluorescence (XRF) for chemical composition and scanning electron microscopy (SEM) for morphology. Analysis of extracted pore water and moisture content determination of Secunda fresh ash and Secunda weathered ash core samples was done in order to evaluate the physico-chemical properties of the fly ash. The chemical partitioning and mobility of metal species in the ash dam was evaluated using the sequential extraction procedure. The XRD spectra revealed quartz, mullite and calcite as the dominant mineral phases in the weathered Secunda ash core samples while Secunda fresh ash contained quartz, mullite and lime. The major oxides identified by XRF analysis for both Secunda fresh ash and Secunda weathered ash include: SiO₂, Al₂O₃, CaO, Fe₂O₃, MgO, Na₂O, TiO₂ and K₂O. The minor oxides identified for both Secunda fresh ash and Secunda weathered ash were P₂O₅, SO₃ and MnO. The trace elements identified for both Secunda fresh ash and Secunda weathered ash were As, Ba, Ce, Co, Nb, Ni, Pb, Rb, Sr, V, Y, Zr and Th. However, U was detected in some of the Secunda weathered ash samples but not in Secunda fresh ash. Both Secunda fresh ash and Secunda weathered ash was classified as class F based on the sum of the oxides of silicon, aluminium and iron by mass and the CaO content as reported by XRF analysis, and further classified as sialic and ferrocalsialic type highlighting the significant levels of Si, Al, Ca and Fe in the fly ash based on XRF analysis. The XRF analysis further showed that brine codisposal on the ash may have been responsible for the slight enrichment of some species such as Na, SO₄²⁻, Mg, K and V in the disposed Secunda weathered fly ash. However, there was no significant accumulation of these species in the disposed fly ash despite continuous addition of an estimated 117.65 billion litres of brine over the 20 year period that… Advisors/Committee Members: Petrik, Leslie F (advisor), Akinyeye, Richard Odunayo (advisor), Gitari, Wilson M (advisor).

Subjects/Keywords: Fly ash; Coal; Fossil fuels; Coal gasification; Weathering; Leaching

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Nyale, S. M. (2011). Chemical, physical and morphological changes in weathered brine slurried coal fly ash . (Thesis). University of the Western Cape. Retrieved from http://hdl.handle.net/11394/5427

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Nyale, Sammy Mwasaha. “Chemical, physical and morphological changes in weathered brine slurried coal fly ash .” 2011. Thesis, University of the Western Cape. Accessed April 10, 2020. http://hdl.handle.net/11394/5427.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Nyale, Sammy Mwasaha. “Chemical, physical and morphological changes in weathered brine slurried coal fly ash .” 2011. Web. 10 Apr 2020.

Vancouver:

Nyale SM. Chemical, physical and morphological changes in weathered brine slurried coal fly ash . [Internet] [Thesis]. University of the Western Cape; 2011. [cited 2020 Apr 10]. Available from: http://hdl.handle.net/11394/5427.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Nyale SM. Chemical, physical and morphological changes in weathered brine slurried coal fly ash . [Thesis]. University of the Western Cape; 2011. Available from: http://hdl.handle.net/11394/5427

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.