應用厭氧酸化及光合產氫系統轉化有機廢水產氫之研究

Feasibility Study on Dark/Photo-fermentation Converting Bio-ethanol Wastewater to Biohydrogen

白明德(M. D. Bai) ； 趙禹杰(Y. C. Chao) ； 盧文章(W. J. Lu) ； 李宏台(H. T. Lee)

《中華生質能源學會會誌》 26卷1&2期 (2007/06) Pp. 15-22

https://doi.org/10.6385/JBESC.200706.0015

摘要

生物產氫技術包含厭氧產氫醱酵與光合產氫技術，前者可利用較多樣、較複雜的生質物，反應速率快，但是反應不完全，產氫轉化率低，後者可將有機物完全氧化，生物電子則轉為氫氣，產氫轉化率高，但是可利用的有機物質種類較少，只可利用小分子的有機物，如單醣類及揮發性脂肪酸等。本研究結合此兩技術應用於乙醇醱酵生質廢水之處理，厭氧醱酵後選用Rhodopseudomonas palustris (BCRC 16408)進行光合產氫之研究，研究結果顯示，乙醇醱酵廢水在厭氧產氫段可回收72〜83 L H_2/kg COD_a，光合產氫部份則受限於氨氮濃度的影響，在氨氮濃度為78 mg-N/L時，氫氣的生成受到抑制，將廢水pH調整在8.5並以氬氣吹拂，經厭氧產氫後，可將廢水的氨氮控制在5 mg-N/L以下，於此條件下，光合菌可成功自廢水中回收300 L H_2/kg COD_a,，整體氫氣的回收量可達厭氧醱酵產氫的4倍以上，因此如何以程序控制或分離使氨氮濃度對光合產氫的影響降低，將成為光合產氫技術應用的關鍵。

關鍵字

生物產氫 ； 光合產氫 ； 氨氮抑制

並列摘要

As the global warming issue and energy crisis become more pressing, hydrogen come from sustainable materials is promising for its sustainability and no contribution to carbon dioxide debts. Biohydrogen technologies convert organic materials into hydrogen by microbes. Dark-fermentation and photo-fermentation are two more feasible technologies among them. Combining these two technologies together can stabilize organic waste and recover hydrogen at the same time. In this research, these two technologies were implemented to treat wastewater, which supplied by an emerging industry, bioethanol fermentation. In this research, 2 sets of batch experiments were conducted to investigate the effect of ammonia in wastewater on hydrogen production. When nitrogen source is not a limit factor, the amount of ammonia has little effect on dark-fermentation, reaching a hydrogen yield up to 71~83 L H2/kg-CODa. On the contrary, photo-fermentation is very sensitive to ammonia. In this case, ammonia constitutes most nitrogen source, whose concentration is about 1,5 g-N/L and the concentration of organic nitrogen is only 0.2 g-N/L. Though a proper dilution and dark-fermentation help to reduce the amount of ammonia, the ammonia concentration is 78 mg-N/L before photo-fermentation. No hydrogen gas was detected during photo-fermentation because of the inhibition of ammonia. As a result, the pH of the wastewater was adjusted to 8.5 and purged with argon before hydrogen fermentation. The approach can successfully control ammonia concentration below 5 mg-N/L and a hydrogen yield up to 300 L H2/kg-CODa was achieved in photo-fermentation. When darkfermentation and photo-fermentation are adopted to treat wastewater in series, the amount of ammonia is a key factor for better recovery of hydrogen.

並列關鍵字

biohydrogen ； photosynthesis hydrogen production ； ammonia inhibition