利用化合自營菌去除高濃度硫化氫之研究

Abstract

養豬場產生的廢氣可被回收利用為沼氣發電，但是沼氣中的硫化氫氣體會侵蝕發電機導致無法發電，硫化氫純化的方式有很多種，其中採用生物法移除硫化氫氣體不但不會對環境造成汙染，成本也比較便宜。因此本研究在實驗室實驗中，從六株硫氧化菌中篩選出兩株去除率佳的菌株，分別是Thcp2和Thcp6做實驗室規模反應器長期測試，經過第二次篩選後，選擇Thcp2在實場反應器進行通氣實驗。在實驗室規模長期測試中硫化氫進流濃度為2000 ppm到3600 ppm之間，使用兩種不同的反應器進行實驗測試，分別為生物滴濾床與生物濾床。在三十二天的長期測試中兩菌株Thcp2和Thcp6去除率平均分別為95 %和80 %，完全去除硫化氫之負荷量分別為150和130 g-S/m3/h，最大去除硫化氫之負荷量為680和630 g/m3/h。實場規模反應器測試中去除率在通氣量5000 ml/min時平均可達75 %，在通氣量2500 ml/min時平均可達90 %，而最大去除負荷為350 g-S/m3/h。經過通氣實驗後發現硫酸根離子為菌株主要代謝產物，在有氧氣的環境下有85 %的代謝產物為硫酸根離子。由實驗結果可得知菌株Thcp2可以有效率去除沼氣中的高濃度硫化氫氣體，未來Thcp2將進行大型實場規模反應器之實驗。

Sludge wastes have been used for energy generation. Since power generator will be corrupted by H2S during consumption. Removal of H2S using biological process is useful for environment and cost friendly. For this reason, two microorganisms Thcp2 and Thcp6 had been selected for lab scale experiment from six isolated microorganisms. The strain Thcp2 was selected for pilot scale experiment due to the highest removal efficiency. The inlet H2S concentration ranged from 2000 to 3600 ppm and two different bioreactors (biotrickling filter and biofilter) were examined in long term experiment. Removal efficiencies were 95 % and 80 % during 32 days examination. The inlet loading H2S were 150 and 130 g/m3/h that were the highest elimination capacity for Thcp2 and Thcp6, respectively. In pilot-scale study, removal efficiency could maintained at 75 % when biogas inlet velocity were 5000 ml/min, was achieved when biogas inlet flow rate was 2500 ml/min, and the highest elimination capacity was 350 g-S/m3/h. Sulfate was found to be the major end-products after biological oxidation of H2S. Almost 85 % H2S recovery as sulfate in aerobic condition. The results showed that the Thcp2 can remove H2S efficiently, and the large pilot-scale test of Thcp2 will be carried out in the near future.