| Summary: | 碩士 === 國立臺灣大學 === 環境工程學研究所 === 107 === Algae-based membrane bioreactor(A-MBR) is a technique which combined traditional photobioreactor with membrane. The membrane can keep the microalgae in system effectively while filtration, and therefore, we can utilize high biomass concentration to remove pollutants in shorter time. The objective of this study is using ceramic membrane in A-MBR to remove the nitrogen and phosphorous nutrients and steroid estrogens.
In the estrogens removing batch test, there were four hypotheses about estrogen removal mechanisms by algae: 1. Algae-mediated biotransformation; 2. Direct-photolysis of estrogens; 3. Algae organic matter(AOM) mediated photolysis; 4. Algae biomass sorption. In results, estrogens wouldn’t be photolyzed by visible light and sorbed by algae biomass. In the comprehensive batch test of biotransformation and photodegradation, the removal effect of P. subcapitata was the most obvious. The residual rate of E2 and EE2 on the 7th day was 8.76 ± 4.29% and 16.54 ± 6.16%. The photodegradation removal induced by AOM of C. vulgaris was the most efficient, and estrogen was not detected after 24 hr reaction.
In A-MBR, the nitrogen removal rate was 63% when the system was stable, and the system has obvious removal effect on the phosphorus only in the initial stage of the reactor operation. The best removal rates of estrogen E2 and EE2 were 41.2% and 42.3%, respectively. Fluorescence excitation emission matrix(EEM) was used to analyze the composition of organic matter in the reactor. It was found that the organic matter in the reactor was consisted of aromatic protein and tryptophan which represents microbial metabolites in initial stage. But the composition of the organic matter in the reactor gradually changed to humic acid and fulvic acid in the later stage of operation.
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