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dc.contributor.authorOjok, Walter
dc.contributor.authorMoodley, Brenda
dc.contributor.authorWasswa, John
dc.contributor.authorNtambi, Emmanuel
dc.contributor.authorWanasolo, William
dc.contributor.authorBolender, James
dc.date.accessioned2023-11-03T10:20:48Z
dc.date.available2023-11-03T10:20:48Z
dc.date.issued2023
dc.identifier.citationOjok, W., Moodley, B., Wasswa, J., Ntambi, E., Wanasolo, W., & Bolender, J. (2023). Role of starch in one pot fabrication of mesoporous gamma-alumina with excellent fluoride sorption capacity. Sustainable Chemistry for the Environment, 3, 100034.en_US
dc.identifier.urihttp://ir.must.ac.ug/xmlui/handle/123456789/3242
dc.description.abstractGreen synthesis of mesoporous γ-AƖ2O3, a cutting-edge material for sustainable application in medicine, engineering, energy, and water treatment, is still challenging. Our study used a one-pot strategy for facile synthesis of γ-AƖ2O3 by sol-gel method using starch from cassava waste. AƖ(OH)3 were bound to the O-H groups of the starch molecule to form the AƖ(OH)3-starch complex in a nano-network confined in starch polymer cages. Its calcination at 500 ℃ produced a mesoporous, highly crystalline water stable γ-AƖ2O3 with a pore size of 2.07 nm and an extensive BET surface area (215 cm2/g). Using the response surface methodology (RSM), the as-synthesized γ-AƖ2O3 was optimized for efficient fluoride removal from water. A central composite design (CCD) was used to study the effect of initial fluoride concentration, pH, contact time, and sorbent dose on fluoride removal efficiency and optimization of the process. The relative importance of the sorption process variables to the fluoride removal process was assessed using ANOVA. The quadratic model showed that the predicted response was significantly correlated with the experimental response (R2 = 0.9667), with sorbent dose and pH being the process’s most influential factors. Optimum conditions for 93.6% fluoride removal efficiency were sorbent dose of 0.5 g, initial fluoride concentration of 10 mg/L, pH 7, and contact time of 137.5 min. A weakly acidic medium favored fluoride removal from water, while the presence of PO43- and HCO3- retarded the process. The sorption data fitted well in the Langmuir isotherm (0.9783) and pseudo-second-order kinetic model (0.9999), indicative of a chemisorption process. The maximum sorption capacity towards fluoride was 207.5 mg/g. A thermodynamic study indicated that the sorption process was spontaneous and endothermic, with increased randomness at the solid-solution interface. Sorption, desorption, sustainability, and leaching tests showed that the sorbent could be used for sustainable fluoride removal at 8.3 USD/1000 liters of safe drinking water.en_US
dc.description.sponsorshipAfrican-German Network of Excellence in Science (AGNES) and the German Academic Exchange Service (DAAD) [Grant number: 91672385]en_US
dc.language.isoen_USen_US
dc.publisherSustainable Chemistry for the Environmenten_US
dc.subjectGreen chemistryen_US
dc.subjectSol-gelen_US
dc.subjectResponse surface methodologyen_US
dc.subjectNanoparticlesen_US
dc.subjectKineticen_US
dc.subjectThermodynamic studyen_US
dc.titleRole of starch in one pot fabrication of mesoporous gamma-alumina with excellent fluoride sorption capacityen_US
dc.typeArticleen_US


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