透過您的圖書館登入
IP:44.200.145.114
  • 學位論文

以雙槽式微生物燃料電池陰極處理含高濃度心血管用藥及抗生素廢水之研究

Using cathode of dual-chamber microbial fuel cell to treat high concentrations of cardiovascular drugs and antibiotics wastewater

指導教授 : 于昌平

摘要


作為一項能源回收技術,微生物燃料電池從被發現、推廣、應用至今,已經有數十年的歷史,其中也衍伸出許多改型,除了功率密度較高的單槽式和微型燃料電池之外,傳統的雙槽式微生物燃料電池之陰極,亦被開發用於製造有價產物,這類微生物燃料電池,能在陽極馴養微生物,並透過調整電阻以及控制陰極的反應條件等方式,在陰極產生出諸如甲烷、氫氣或過氧化氫等物質,其中過氧化氫能用於Fenton反應,降解生物難分解性物質,也可利用此過程中的pH值上升,驅動鹼熱水解反應,進行抗生素降解。這些處理程序,具有能應對近年生物處理所面臨幾項挑戰的潛力,包括:能源回收、生物難降解性物質以及抗藥性基因擴散等,值得進行深入探討。 本研究分為兩個項目,第一個項目為電Fenton實驗,將測試各種不同電極材料之雙氧水產率,並以此驅動電Fenton反應,降解生物難降解性藥品,如美托洛爾。第二個項目為鹼性環境加熱水解,側重於鹼的利用,在生成雙氧水的過程中,會消耗大量的陰極的氫離子,導致pH值大幅升高,可能抑制Fenton反應的進行,因此對於能通過鹼熱水解反應降解之污染物-例如四環素,可利用陰極的鹼性環境,達到處理的效果,降低操作過程中的鹼添加。 電Fenton實驗,於陽極使用含磷酸鹽緩衝溶液的模擬污水並以葡萄糖混合溶液作為碳源,在陰極則以pH調整至3之Na2SO4作為電解質,本研究測試了低比表面積的板狀材料石墨棒與鋼板、高比表面積的活性碳塗佈電極與奈米碳管塗佈電極、具有催化性的TiO2電極、以及同時具有高比表面積與催化性的氧化錳碳氣凝膠電極,研究發現催化性材料與其他材料,具有不同的反應趨勢,且同時具有催化性與高比表面積的氧化錳碳氣凝膠,其雙氧水產率達到石墨棒的15倍以上。以碳氣凝膠電極,進行以微生物燃料電池驅動的電Fenton反應,可在120 min內將125 mg L-1之美托洛爾去除60%以上。 鹼性環境加熱水解實驗,則在陰極加入100 mg L-1之四環素,並測試石墨與碳氣凝膠電極在開路、閉路或無電極狀態之下,於25、35、45、55 ℃,對四環素的去除效能。因為pH值的上升,所有閉路槽之四環素降解速率都優於開路槽。且溫度增加會使四環素的半衰期大幅縮短。TOC的分析則發現,不論開路或閉路槽都並未發生顯著的TOC去除,暗示四環素被轉化成二次產物。高解析度質譜儀指出,透過鹼熱水解反應,四環素的官能基群已經發生變化,可能會導致其抗菌毒性降低。而透過微生物毒性測試的驗證,經過陰極槽反應的四環素抗菌活性已經降低。研究結果顯示透過微生物燃料電池驅動鹼熱水解反應,可以有效的對含高濃度四環素的污水進行預處理,降低其抗菌活性,減少後續生物處理中,抗藥性基因出現的風險。

並列摘要


The application of microbial fuel cells (MFCs) on wastewater treatment has been evolving rapidly in recent years. It simultaneous removes pollutants and recovery energry in duving wastewater treatment process. There were many different MFC designs. In addition to single-chamber and micro chamber MFC capable of generating high power density, dual-chamber MFCs, which carry out reactions seprtatedly in indinduel chambers can produce valuable byproducts on the cathode. In the dual-chamber MFC, the microorganisms grow in the anode chamber and valuable byproducts such as H2, CH4 and H2O2 were generated in the cathode chamber depending on different design and external resistance. By reducing the external resistance of MFCs, the generation of H2O2 at the cathode could reach a concentration level to drive the Fenton reaction, which provides a strong oxidant to degrade pollutants. The rising pH in the cathode chamber can also drive alkaline thermal hydrolysis reaction, to degrade pollutants which are unstable characteristics under alkaline conditions such as tetracycline. These treatment procedures have potential to cope with several challenges faced by biological treatment in recent years: energy recovery, recalcitrant substances, and the spread of drug-resistant genes. This research has two objects; in the object 1 I tested the hydrogen peroxide yield of various electrode materials, and used them to drive the electro-Fenton reaction to degrade refractory pollutants, such as metoprolol. In the object 2, the experiment focused on the utilization of alkali. In the process of generating hydrogen peroxide, a large amount of hydrogen ions from the cathode will be consumed, resulting in a significant pH increase, which may inhibit the Fenton reaction. However, this pH increase can be used to achieve degradation of unstable pollutants under the alkaline condition, such as tetracycline. In object 1, a glucose medium containing phosphate buffer solution was used as an anolyte, and Na2SO4 solution with pH adjusted to 3±0.1 was as a catholyte. Cathode materials were selected according to previous electro-Fenton systems, such as non-catalytic materials such as steel plate and graphite, high specific surface area materials such as activated carbon and carbon nanotubes, catalytic materials such as platinum titanium, and high specific surface area catalytic materials such as manganese oxide/carbon aerogel. Our research have found that catalytic materials and other materials had different reaction trends, and manganese oxide carbon aerogel with catalytic properties and high specific surface area, achieved the H2O2 production rate is more than 15 times that of graphite rods. Using carbon aerogel electrode to carry out electro-Fenton reaction, 125 mg L-1 of metoprolol can be removed by more than 60% in 120 mins. In the object 2, to test the degradation of tetracycline under different reaction conditions, including no-electrodes, carbon-aerogel-open-circuit, graphite-open-circuit, carbon-aerogel-closed-circuit, and graphite-closed -circuit, condictions 100 mg L-1 tetracycline was added, and the temperature was set to 25, 35, 45and 55 ℃, respectively. It was observed that tetracycline degradation rates under closed circuit conditions were faster than those under open circuit conditions due to the rising pH in the cathode chamber of closed circuit MFCs, and the temperature increase could result in a decrease in half-life of tetracycline degradation. The TOC analysis showed that most TOC was not removed after 48 h reaction, suggesting tetracycline was mainly transformed to byproducts in the cathode chamber. High resolution mass spectrometry identified the transformation products resulting from the alkaline thermal hydrolysis of tetracycline, and the minimum pharmacophore of tetracycline was altered, which would lead to the loss of antibacterial activity. Microtox tests confirmed the reduction in the toxic effect of tetracycline to luminescent bacteria after treatment in the cathode chamber. Our results have demonstrated the effective degradation of tetracycline using MFC-driven alkaline thermal hydrolysis, which will have potential to be a pretreatment process to assist the subsequent biological treatment processes to destroy high concentrations of antibiotics in the wastewater.

參考文獻


Abdessalem, A. K., Oturan, N., Bellakhal, N., Dachraoui, M., Oturan, M. A. (2008). Experimental design methodology applied to electro-Fenton treatment for degradation of herbicide chlortoluron. Applied Catalysis B: Environmental, 78(3), 334-341.
Adekunle, A., Vidales, A. G., Woodward, L., Tartakovsky, B. (2020). Microbial fuel cell soft sensor for real-time toxicity detection and monitoring. Environmental Science and Pollution Research, 1-11.
Agwuh, K. N., MacGowan, A. (2006). Pharmacokinetics and pharmacodynamics of the tetracyclines including glycylcyclines. Journal of Antimicrobial Chemotherapy, 58(2), 256-265.
Ai, Z., Mei, T., Liu, J., Li, J., Jia, F., Zhang, L., Qiu, J. (2007). Fe@ Fe2O3 core-shell nanowires as an iron reagent. 3. Their combination with CNTs as an effective oxygen-fed gas diffusion electrode in a neutral electro-Fenton system.The Journal of Physical Chemistry C, 111(40), 14799-14803.
Ai, Z., Xiao, H., Mei, T., Liu, J., Zhang, L., Deng, K., Qiu, J. (2008). Electro-Fenton degradation of rhodamine B based on a composite cathode of Cu2O nanocubes and carbon nanotubes. The Journal of Physical Chemistry C, 112(31), 11929-11935.

延伸閱讀