Abstract
本實驗主要是探討以生物濾床(填充堆肥/矽藻土) 與生 物滴濾床(填充矽藻土)處理漁產加工廠區易 逸散之三甲基胺廢氣 時，兩種反應器去除效果之 比較及以生物滴濾床中氮平衡關係式 計算有機氮 進入生物滴濾床內，各種氮形式所佔的比例，推 斷生物滴濾床中有機氮所可能發生的行為，並驗 證Tang et al. 所提出的生物濾床穩定態動力模 式之準確性。實驗操作分為穩態 與非穩態狀況， 穩態部份以改變入口濃度及進氣流速，探討生物 濾床及生物滴濾床對三甲基胺去除率之影響；在 非穩態部份，分 別觀察起始操作、突然改變入口 濃度及中斷供給一星期後再啟動 等狀況，生物濾 床與生物滴濾床對三甲基胺的適應能力。由實驗 結果得知，在穩態部份，生物濾床與生物滴濾床 對三甲基胺的去 除能力均會隨著入口濃度的增加 與進氣流速的提高而逐漸降低， 但無論在相同入 口濃度或進氣流速條件下，生物滴濾床的去除能 力比生物濾床高。生物濾床的最大消解能力約為 55g/m3hr。由於 水分的存在及三甲基胺可溶於水 的特性，在生物滴濾床內三甲基 胺會進行好氧硝 化反應，因此在循環水中可測得出硝酸根離子， 而經由氮平衡之計算，推算出氮平衡中有約2%的 氮氣存在，間接 推斷可能由於生物膜厚度過厚， 氧氣不易傳送至生物膜內部，因 此在生物膜內部 有厭氧脫硝作用發生，產生少許氮氣。此外，對 Tang et al.所提出的生物濾床穩定態動力模式 與實驗數據相較 ，可發現模式可相當準確的模擬 本次實驗中生物濾床的動力行為 。在非穩態部份 ，無論在起始操作過程、入口濃度的突然提高及 中斷供起一星期後再啟動，生物滴濾床對外在條 件改變的適應力 均比生物濾床良好，此與待去除 之污染物性質應有相當關係，因 此，對含水溶性 良好的污染物廢氣，宜採用生物滴濾床反應器處 理之。 Biofiltration of polluted gas stream containing malodorous trimethylamine (TMA) was studied in this work. The experiments were structured in two laboratory-scale reactors. One is the biofilter with a mixture of sieved compost and diatomaceous earth particles as the filter material, and another is the trickle-bed bioreactor with diatomaceous earth particles as the reactor material, on both which the microorganisms were immobilized. The inlet concentration of TMA varied from 0.174 to 2.61 g/m3, whilethe superficial inlet gas stream velocity ranged from 1.34 to 2.95 cm/s. In the steady state part, the removal efficiency of trimethylamine in the biofilter and trickle-bed bioreactor decreased as the inlet gas velocity or TMA inlet concentration increase, and the elimination capacity of the biofilter was 55 g/m3hr. Moreover, due to TMA easy dissolved in the water, TMA in the trickle-bed bioreactor could reacted aerobic nitrification, and detected nitrate in the recycle nutrient liquid. Since nitrogen gas exited about 2% from calculation nitrogen balance, it showed that anaerobic denitrification did react due to the overthickness of biofilm. In addition, compared to the model in the steady state biofilter proposed by Tang et al., the experiment data could fit the curves drawn by the model. In the portion of unsteady state, the trickle-bed bioreactor could acclimate to the change the environment better and reached to new steady state faster than the biofilter.