以平板式陶瓷膜應用於微藻膜生物反應槽去除廢水中氮磷營養鹽及內分泌干擾物質

Applying flat ceramic membrane in algae-based membrane bioreactor to remove nitrogen and phosphorous nutrients and EDCs from wastewater

葉馨翊(Hsin-Yi Yeh)

指導教授 ： 于昌平

國立臺灣大學/工學院/環境工程學研究所/碩士(2019年)

https://doi.org/10.6342/NTU201901863

摘要

本研究的主題是將傳統培養藻類的光生物反應器結合陶瓷膜而形成的微藻膜生物反應槽，觀察其對於廢水中氮磷營養鹽與雌激素的去除效果；利用薄膜生物反應槽能在過濾水的同時將生物質截留於反應槽中的特性，使得系統內累積的生物質濃度能比傳統連續流的生物培養系統高許多而達到在短時間內處理更大量廢水的目的，同時以藻類為基礎的薄膜生物反應槽在操作時所廢棄的高濃度藻液也有許多再利用的潛力。本研究使用人工二級廢水來模擬污水出處理廠的二級廢水，此類廢水有機物含量低但仍有許多氮磷營養鹽及微量的新興污染物，藉由長時間的操作觀察微藻膜生物反應槽對於氮磷營養鹽的去除效果，並加入類固醇雌激素這類新興污染物觀察其在反應槽中的濃度變化。
在批次實驗中假設雌激素在培養藻類的環境中有四種可能的去除途徑，分別為直接光降解、藻類代謝所引發的生物轉化、藻類有機物質(AOM)誘發的光降解反應及藻類生物質的吸附現象。實驗結果得到雌激素本身不會在可見光條件下被破壞，且在ppm等級的濃度下對於生物質也無明顯的吸附現象發生。其主要的去除途徑以生物轉化與AOM誘發的光降解。在生物轉化與光降解的綜合批次試驗中羊角月牙藻的去除效果最為明顯，在實驗週期最後一天時E2與EE2的殘留率為8.76 ± 4.29%和16.54 ± 6.16%；而單純AOM誘發的光降解去除以小球藻效率最好，在經過一天的反應即測不到雌激素。
在連續流的微藻膜生物反應槽試驗中，系統穩定時氮營養鹽去除率最高來到63%，而系統對於磷只有在反應槽建設初期有看到明顯去除效果；雌激素E2與EE2最好去除率則分別來到41.2%與42.3%。利用螢光激發發射矩陣分析反應槽內有機物組成變化得知反應槽內有機物初期主要以芳香烴蛋白及代表微生物代謝產物的色胺酸為主，但到運行後期則漸漸轉為腐植酸與黃酸類物質。

關鍵字

微藻膜生物反應槽 ； 類固醇雌激素 ； 藻類有機物 ； 陶瓷膜 ； 光降解

並列摘要

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.

並列關鍵字

Algae-based membrane bioreactor ； Steroid estrogens ； Algae organic matter ； Ceramic membrane ； Photodegradation

參考文獻

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