The Application of Immobilized Microorganism Techniques for Wastewater Denitrification Treatment-Material Case Study of Ca-Alginate as Immobilized Support
| Autor: | Ting Chang-Kai, 丁中凱 |
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| Rok vydání: | 1998 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 86 The purpose of this research is to conduct feasibility study on the use of the aerobic conditions for wastewater denitrification treatment with immobilized support of calcium alginate, and to evaluate the influence on micro-porosity, activity and mechanical strength by the additives including polyethylene glycol (PEG) and polyethylene imine (PEI) on the calcium alginate support, in order to screen the method and material for immobilized support with potential for further development and to assess the comparative results with traditional suspended growth by extended aeration activated sludge process.From the result of this study, the addition of PEI contributed significantly to the mechanical strength of calcium alginate support, but reduced the internal porosity of the support, leading to increase the resistance of mass transfer as well as inhibit the activities of the support. The addition of PEG can effectively solve such problem, since PEG is a hydrophilic polymer that can be gradually leached out from calcium alginate support to increase the internal porosity of the support, however, PEG cannot increase the mechanical strength of calcium alginate support. Thus, as the addition of PEI and PEG are complementary in nature for their characteristics and effectiveness. Besides, the experimental results in this research indicated that the optimum mixing ratios for Alg: PEG:PEI in support composition were 4:4:6 (%)，respectively. After experiment with oxygen uptake and mechanical strength testing, the said composition (Alg:PEG:PEI= 4:4:6(%) ) possessed superb biological activity, high porosity and adequate stability, in continuous treatment of municipal raw sewage for 60 days with no loss of stability. Similar result was obtained with municipal sewage in this research with upflow aeration fluidized bed reactor (UAFBR) filled with 10 % (w/v) of Alg-PEG-PEI (4:4:6, %) carrier under hydraulic retention time (HRT) of 8 hours, the result of treatment shown that the average concentration of the effluent from UAFBR contained 16.0 mg/l of NO- 3-N, NH3-N removal efficiency of 91.4%, indicating the super denitrification removal efficiency of Alg-PEG-PEI immobilized microbiological support in aerobic condition, from which it can be concluded that this method of immobilization of Alg-PEG-PEI support deserves further investigation and potential in future development. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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