This dissertation investigates the possibility of producing zeolites from municipal solid waste ash, MSW ash, by using hydrothermal treatment alone and by introducing fusion at 550 °C prior to hydrothermal treatment. The study was performed at different treatment conditions where silica/aluminum ratio of 13.9 and 2.5, hydroxide concentrations of 1.5N, 2.5N and 3.5N, temperatures at 100°C and 60 °C and time at 6, 24 and 72 hours were the major variables used to study zeolites synthesis process. The possibility of forming zeolites A, P1 and X was of particular interest in the present study. Factors, mechanism and modeling of zeolite A were investigated thoroughly in the present study. Zeolite synthesis process was evaluated using X-Ray diffraction to study different formed zeolite types and their chemical composition as well as their percentages. Morphological and physical characteristics of the produced zeolitic materials were evaluated by scanning electron microscopy,
and cation exchange capacity property, CEC.The findings indicate that hydrothermal process did not succeed in producing significant amounts of zeolites. Consequently, the CEC of the produced zeolitic materials were much below the available commercial zeolite materials.Fusing the ash prior to hydrothermal treatment successfully produced sodium aluminum silicates and sodium silicates precursors to zeolite A formation. Fusion followed by hydrothermal treatment yielded significant amounts of zeolite A, at maximum value of 38.8% with CEC up to 245.0 meq/100g, which is within the range of commercially available zeolites. Experimental design analysis performed on zeolite A synthesis showed that zeolite A formation was reproducible and equation of interaction between different used conditions was established. Mechanism of zeolite A formation was concluded to be solution transport mediated process that involved both gel and solution interaction rather than being pure solution reaction or pu
re gel transformation process. Solution super saturation and optimum silica/aluminum ratio were the driving force for nucleation of zeolite A.
| Identifer | oai:union.ndltd.org:USF/oai:scholarcommons.usf.edu:etd-3687 |
| Date | 01 June 2006 |
| Creators | Sallam, Maysson |
| Publisher | Scholar Commons |
| Source Sets | University of South Flordia |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Graduate Theses and Dissertations |
| Rights | default |
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