AI SearchApplication of Chlorella sp. and chitosan for Au recovery from mine tailing wastewater
Call Number: AIT Thesis no.EV-07-38 Material type:
SeriesSeries: Asian Institute of Technology. Thesis ; no. EV-07-38Publication details: Pathum Thani, Thailand : Asian Institute of Technology, 2007Description: 51 p. : illSubject(s): Online resources: Dissertation note: Thesis (M.Eng.) - Asian Institute of Technology, 2007 Summary: Batch experiments for Au recovery by adsorption using dried Chlorella sp. and chitosan and desorption were conducted. Adsorption and desorption isotherm results suggested that the multilayer adsorption of Au by Chlorella sp. and chitosan took place. Effects of influencing parameters for adsorption such as equilibrium contact time, pH and Chlorella sp. and chitosan concentrations were investigated. For desorption tests, pH, equilibrium contact time and amount of 0.1 M thiourea were varied. The equilibrium contact times for Au adsorption on Chlorella sp. and chitosan were 24 hours and 6 hours, respectively. The equilibrium contact time for Au desorption for both Chlorella sp. and chitosan was 2 hours. The pH 3 was found to be optimum for Au adsorption for both Chlorella sp. and chitosan; while pH 2 was the optimum for Au desorption. The optimum concentration of C/ilorella sp. for Au adsorption was 200 mg/mg-Au and chitosan was 100 mg/mg-Au. The ratio of Chlorella sp. and chitosan of 1/3 was found to be optimum for Au adsorption at pH 3 for 24 hours contact time and 200 mg/mg-Au of mixing sorbents concentration. The ratio of 0.1 M thiourea and Chlorella sp. or chitosan of 0.1 ml/mg was found to be optimum for Au desorption. At the optimum adsorption conditions, the percents of Au adsorbed by Chlorella sp., chitosan and the 1/3 mixture were 85.50%, 94.60% and 96.10%, respectively, corresponding to the Au adsorption ratios of 4.15, 9.74 and 4.97 mg/g, respectively. Probably, due to the high specific surface area, chitosan was found to be more effective in Au adsorption than Chlorella sp. The percents of Au desorption by thiourea for Chlorella sp. and chitosan were 92.22% and 92.14%, respectively. Based on cost benefit analysis; Chlorella sp. was not cost-effective biosorbent for Au adsorption and desorption while for chitosan and the mixture were cost-effective.
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Thesis (M.Eng.) - Asian Institute of Technology, 2007
Batch experiments for Au recovery by adsorption using dried Chlorella sp. and chitosan and desorption were conducted. Adsorption and desorption isotherm results suggested that the multilayer adsorption of Au by Chlorella sp. and chitosan took place. Effects of influencing parameters for adsorption such as equilibrium contact time, pH and Chlorella sp. and chitosan concentrations were investigated. For desorption tests, pH, equilibrium contact time and amount of 0.1 M thiourea were varied. The equilibrium contact times for Au adsorption on Chlorella sp. and chitosan were 24 hours and 6 hours, respectively. The equilibrium contact time for Au desorption for both Chlorella sp. and chitosan was 2 hours. The pH 3 was found to be optimum for Au adsorption for both Chlorella sp. and chitosan; while pH 2 was the optimum for Au desorption. The optimum concentration of C/ilorella sp. for Au adsorption was 200 mg/mg-Au and chitosan was 100 mg/mg-Au. The ratio of Chlorella sp. and chitosan of 1/3 was found to be optimum for Au adsorption at pH 3 for 24 hours contact time and 200 mg/mg-Au of mixing sorbents concentration. The ratio of 0.1 M thiourea and Chlorella sp. or chitosan of 0.1 ml/mg was found to be optimum for Au desorption. At the optimum adsorption conditions, the percents of Au adsorbed by Chlorella sp., chitosan and the 1/3 mixture were 85.50%, 94.60% and 96.10%, respectively, corresponding to the Au adsorption ratios of 4.15, 9.74 and 4.97 mg/g, respectively. Probably, due to the high specific surface area, chitosan was found to be more effective in Au adsorption than Chlorella sp. The percents of Au desorption by thiourea for Chlorella sp. and chitosan were 92.22% and 92.14%, respectively. Based on cost benefit analysis; Chlorella sp. was not cost-effective biosorbent for Au adsorption and desorption while for chitosan and the mixture were cost-effective.
A thesis submitted in paitial fulfilment of the requirements for the degree of Master of Engineering in Environmental Engineering and Management.
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