Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/4915
標題: 厭氧生物處理四氯乙烯代謝方式之探討
作者: 郭育仁
關鍵字: 四氯乙烯;熱篩法;硫酸鹽還原菌;產氫菌;鹵化呼吸菌
出版社: 環境工程學系
摘要: 
本實驗研究的目的,乃利用熱篩法或甲烷菌抑制劑(BES)的添加,將甲烷菌篩除,探討混合族群中非甲烷菌在四氯乙烯厭氧脫氯的過程中所扮演的角色。結果發現,當BES濃度由0 mM增加至200 mM,四氯乙烯的代謝不但沒有被抑制,反而具有促進的效果,顯示混合族群中的非甲烷族群,具有較佳的脫氯效果。當硫酸鹽濃度由5mM增加至20 mM時,熱篩組與未熱篩組都顯示出硫酸鹽對於脫氯的現象並無助益,而當硫酸鹽濃度由50 mM增加至200 mM時,熱篩組與未熱篩組都顯示出硫酸鹽對於脫氯的具有抑制的現象。硫酸鹽還原菌計數試驗中也並未觀察到硫酸鹽還原菌的菌落,顯示混合族群中並無硫酸鹽還原菌的存在。添加200 mM BES後,加入不同濃度的乳酸量(0∼20 mM)的實驗中,可以發現隨著乳酸量的提高,四氯乙烯的初始代謝率及總代謝量大幅增加,顯示在無甲烷菌及硫酸鹽還原菌的狀態下,產氫菌及利用氫氣行鹵化呼吸作用(halorespiration)的脫氯菌可能為混合族群中,代謝四氯乙烯的主要菌種。藉由100 mM BES的添加後,加入乳酸及相等於乳酸量的醋酸鈉及氫氣做比較,以釐清產氫菌及鹵化呼吸菌,何者為混合族群中代謝四氯乙烯的主要菌種,結果顯示本族群在無甲烷菌及硫酸鹽還原菌的狀態下,四氯乙烯以產氫菌的代謝約佔5%,以鹵化呼吸菌的脫氯約佔95%。

In this study, the heat pretreatment and the addition of inhibitor (BES) were used to sieve methanogenic cells and then to confirm the anaerobic dechlorination of tetrachloroethylene (PCE) by non-methanogenic cells. With the addition of BES from 0 to 200 (mM), it was found that BES did not inhibit the dechlorination of tetrachloroethylene. On the contrary, the addition of BES was helpful to enhance the dechlorination of PCE. The experimental results showed the dechlorination of PCE by non-methanogenics was superior to methanogenics. For both of the heat pretreatment and non-heat pretreatment of cells, the dechlorination of PCE did not increase with the increase of SO42- from 5 to 20 (mM). However, when the concentrations of sulfate increased from 50 to 200 (mM), the dechlorination of PCE was inhibited. In the experiment of sulfate-reducing bacteria count, sulfate-reducing bacteria were not found in this mixed culture. After the addition of 200 (mM) BES, the PCE removal rate increased significantly as the concentrations of lactate increased from 0 to 20 (mM). The experimental results indicated that hydrogen-producing bacteria and halorespiring bacteria played the major role in the dechlorination of PCE, but not methanogenic or sulfate-reducing bacteria. In order to understand the cells responsible for the dechlorination of PCE, lactate or both acetate and hydrogen were used as the substrate. The experimental results indicated that the dechlorination of PCE resulted from both hydrogen-producing bacteria and halorespiring bacteria. However, halorespiring bacteria played the most significant role for the dechlorination of PCE. More than 95% of PCE dechlorination resulted from halorespiring bacteria.
URI: http://hdl.handle.net/11455/4915
Appears in Collections:環境工程學系所

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