Investigation of the effects of cultivating water quality by immobilized Chlorella sp.
| Autor: | Wen-Lung Lin, 林文隆 |
|---|---|
| Rok vydání: | 2006 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 94 The main purpose of this research was to investigate the effects of the cultivating water quality by the immobilized Chlorella sp.. The relevant foundamental batch type tests of this research were first conducted. It was to investigate the influence of ammonium removal by the immobilized Chlorella sp. under different conditions. These conditions included different culture media (green algae and Bristol culture media), different photoperiods, and different ammonium concentrations of synthetic wastewaters. According to the results of tests, the freshwater alga Chlorella sp. which cultivated in Bristol medium and entrapped in Na-alginate as algal beads had a higher ammonium removal rate than those cultivated in green algae medium. The algal beads under continuous illumination also had a higher ammonium removal rate than the algal beads under intermittent illumination (12 hr brightness / 12 hr darkness). The testings using synthetic wastewaters with different ammonium concentrations obtained that during the initial testing section, the ammonium removal rate of the algal beads would increase as the ammonium concentration raised. The maximum average ammonium removal rate was demonstrated up to about 20.41 mg/l/day at high ammonium concentrations. This research also obtained that the trace elements in synthetic wastewaters could improve the ammonium adsorptive ability of blank alginate beads, and the saturated adsorptive concentration was accumulated to about 38.65 mg/l. It also showed that the algal beads also held the abilities of nitrite and nitrate removal. The actual tests using the reciculating-water culture system with the hydraulic retention time (HRT) 2 hr were performed. These tests included the comparison with no algal beads and the influence of the higher initial ammonium concentration. The testing results showed that the algal beads could effectively remove ammonium and nitrite and obtained lower concentrations of the peaks than those with no algal beads happened in the system. The average ammonium and nitrite removal efficiencies of the algal beads in the actual tests were about 65 and 8%, and the average ammonium and nitrite removal rates were about 26.61 and 48.29 mg/day, respectively. When the ammonium concentration was higher during the initial testing section, the average ammonium and nitrite removal efficiencies of the algal beads would decrease to about 22 and -1%, respectively. However, the average ammonium removal rate of the algal beads was raised to about 32.25 mg/day, while the average nitrite removal rate was decreased to about 6.73 mg/day. The tests also verified that the algal beads held the abilities to remove the ammonium and nitrite contained in the recirculating-water culture system. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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