Application of Chlorella sp. and chitosan for Au recovery from mine tailing wastewater | |
| Author | Pavinee Prasertchai |
| Call Number | AIT Thesis no.EV-07-38 |
| Subject(s) | Chlorella Chitosan Heavy metals--Physiological effect Gold mines and mining--Thailand--Pichit|xWaste disposal--Environemntal aspects |
| Note | A thesis submitted in paitial fulfilment of the requirements for the degree of Master of Engineering in Environmental Engineering and Management. |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. EV-07-38 |
| Abstract | 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. |
| Year | 2007 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. EV-07-38 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Environmental Engineering (EV) |
| Chairperson(s) | Chongrak Polprasert; |
| Examination Committee(s) | Chongrak Polprasert;Preeda Parkpian; |
| Scholarship Donor(s) | RTG Fellowship.; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2007 |