Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/5293
標題: 厭氧顆粒性污泥處理四氯乙烯之研究
作者: 劉煌濱
Pin, Liu Huang
關鍵字: tetrachloroethylene;四氯乙烯;granular sludge;anaerobic/aerobic;顆粒污泥;厭氧/好氧
出版社: 環境工程學系
摘要: 
本研究主要目的在利用批次實驗的方式,探討添加氧氣於反應瓶之瓶頂空間,使厭氧性顆粒性污泥形成具有厭氧微生物(內層)與好氧或兼氣微生物(外層)的高度微生物量,使得四氯乙烯能有快速的降解效率,並探討此系統中之可能會累積的中間產物,以達到最佳生物復育之結果,同時討論基質濃度多寡與添加方式對於四氯乙烯降解效率有何影響。藉由此實驗之結果,提供在UASB(Upflow Anaerobic Sludge Bed)連續流方式處理四氯乙烯的操作上之參考。在單次添加基質方面,當醋酸鈉濃度由50 mg/L提升為500 mg/L,其四氯乙烯總代謝速率則由原先的4.29 nmol PCE/g-VS•d增加至8.15 nmol PCE/g-VS•d。同時,在半連續添加醋酸鈉濃度由100 mg/L 提高至500 mg/L時,四氯乙烯的最終去除率由35 %增加至52%,亦即半連續添醋酸鈉濃度愈高總去除率愈高,且半連續添加方式的最低去除率近似單次添加方式最高去除率,意即半連續添加方式較單獨添加醋酸鈉為佳。添加氧氣於反應瓶之瓶頂空間時,造成結合厭氧/好氧生物以降解四氯乙烯。氯化乙烯類在頂瓶空間添加氧氣實驗中發現,四氯乙烯在厭氧下的確有較高的降解效率,然而三氯乙烯偏向於好氧環境,至於二氯乙烯及氯乙烯則在低氧氣量有較佳的降解情形而於瓶頂空間氧氣量為5.2 % ~10.4 %時,則有最佳之降解效率。此外,未馴化與微馴化顆粒性污泥的比較之中,可以發現無添加氧氣去除四氯乙烯時,兩者之間的差異均在5 %之內,證明了馴化動作對於未馴化顆粒性污泥降解四氯乙烯並無差別,但經厭氧四氯乙烯馴化的顆粒污泥在厭氧/好氧環境下對四氯乙烯有較快的去除率,其可能的原因是對於毒性物質的耐受性提高,故若以顆粒性污泥的厭氧/好氧型式處理四氯乙烯時,建議還是用馴化過的顆粒性污泥,以期有較佳的四氯乙烯降解速度。

The upflow anaerobic sludge bed (UASB) process was superior to be operated under coupled anaerobic/aerobic conditions via its granular sludge. It seems a good idea to complete the sequential degradation of tetrachloroethylene (PCE) with this coupled anaerobic/aerobic condition. The main objective of this study was to discuss the effect of external addition of oxygen on the biodegradability of PCE and the formed intermediates under a simultaneous anaerobic/aerobic system. The effects of different concentrations and addition modes of substrate (sodium acetate) on the biodegradability of PCE under an anaerobic system were studied. And, the acclimation effect on the two systems was also explored.
The experimental results of external oxygen additions indicated that under the oxygen content of 5.2 to 10.4 % in the headspace of the reaction bottles, the anaerobic/aerobic coupled system performed a higher degradation efficiency for chlorinated ethenes. The results showed that an increase in the concentrations of acetate from 50 to 500mg/L increased the total PCE dechlorination rates from 4.29 to 8.15 nmol PCE/g-VS-d under the batch mode of substrate addition. Furthermore, increasing the concentrations of acetate from 100 to 500 mg/L under the semi-continuous addition mode increased the final removal rate from 35 to 52 %. The results also showed that the minimum total removal rate under a semi-continuous mode was similar to the maximum total removal rate under a batch mode. Therefore, the semi-continuous acetate addition was better than the batch mode. And, the result showed no significant effect on the biodegradability of PCE for the anaerobic system. However, after being acclimated, the PCE removal rate in the simultaneous anaerobic/aerobic system was higher than the absolute anaerobic system, which could be due to the improved toxic resistance of the granular sludge through the acclimation. Thus, if PCE would be treated by a coupled anaerobic/aerobic system, it was suggested that the acclimated granular sludge should be used for well-dechlorination of PCE.
URI: http://hdl.handle.net/11455/5293
Appears in Collections:環境工程學系所

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