利用生物氧化法處理高濃度硫化氫之研究

Abstract

本研究為利用養豬場廢水污泥中篩選之微生物 (硫氧化菌) ，進行代謝高濃度 (＞2000 ppm) 硫化氫以達到去除之目的。經實驗室及實場篩菌步驟後，篩選一株去除率最高的菌種 (C1)，以拉西環 (Raschig ring) 作為生物載體進行固定化，探討不同氣體滯留時間與循環水流量對硫化氫去除效率之影響。在硫化氫去除實驗中，固定化的生物反應器通以硫化氫混合氣體 (1% 硫化氫 + 空氣) ，在固定循環水流量 (9.0 l/min) 和進流氣體濃度 (1900 ~ 2200 ppm) 的操作條件下，改變不同進氣流量 (200、400、800、1600 ml/min)，評估此系統之除硫效能。經過二十天測試，去除率最高可達98 % (氣體流量為200 ml/min)，最低仍維持45 %去除率 (氣體流量為1600 ml/min)，但若循環水流流量提高至15.6 l/min，氣體流量固定為1600 ml/min時，去除率可上升至55 %。此外，經代謝產物分析結果得知，元素硫為主要代謝物，若能改進現有反應器設計，以有效移除系統中累積之元素硫，應可提高硫化氫去除效果。

In this study, neutrophilic bacteria isolated from sludge were used to eliminate H2S. The strain C1 was selected due to the highest elimination of H2S. The strain C1 was further immobilized on the carrier Raschig ring to study the effect of different conditions including gas resistance time and liquid-cycling flow rate on the influence and the efficiency of biofiltration system. In this study, we tried to eliminate the concentration of H2S from 2000 ppm to less than 100 ppm. In the experiment, biotrickling filter immobilization with C1 was aerated with gas mixture (H2S (1%) + air) which concentration was about 1900 ~ 2200 ppm. The gas flow rate was 200, 400, 800, 1600 ml/min, respectively, and the liquid flow rate was 9.0 l/min in the experimental system. After 20 days’ tests, the highest removal efficiency was 98 %, and the lowest was still remained at 45 %. When the liquid flow rate was increased to 15.6 l/min, the removal efficiency would elevate to 55 %. Besides, this study also determined the metabolite and confirmed that the main metabolic product was sulfur. These results can help to improve the removal efficiency of H2S and its metabolite of the system.