本研究先以批式活性汙泥法，測試未馴養及已馴養活性污泥對降解含酚廢水之差異性，再以連續流沉浸式薄膜生物反應槽處理高酚濃度之廢水，求得水力停留時間，作為合理設計處理高酚濃度廢水反應槽之參考依據。在150 mgL-1低酚濃度廢水，不同活性污泥濃度下，未馴養汙泥濃度對酚降解所需時間有顯著影響，提高汙泥濃度可降低生物降解所需時間。但以馴養汙泥降解低酚濃度廢水則無明顯差異，而在2000 mgL-1高酚濃度時，則汙泥濃度提高可降低降解所需時間。當酚濃度高達3000 mgL-1時，仍可有效降解，但相對於未馴養汙泥，已馴養活性污泥可較快速完全降解。以2000 mgL-1為例，只需50小時，而未經馴養之汙泥則需80小時。由此批式試驗降解高酚濃度廢水所需之時間，可做為探討薄膜生物反應槽處理高酚濃度廢水所需水力停留時間之參考。以沉浸式薄膜生物反應槽處理高濃度含酚廢水，所需HRT會隨著酚之濃度增加而增加，而提高MLSS濃度則可降低HRT。然而酚濃度由1000 mgL-1增加至2000 mgL-1時，水力停留時間僅些微增加1~2小時，但由2000 mgL-1增加至3000 mgL-1時，且提高MLSS濃度下，水力停留時間則大幅增加6~7小時，推測應為高酚濃度對微生物毒性效應加劇所致。薄膜在經過一段時間過濾後，會產生積垢，需進行薄膜離線清洗，當離線清洗時，比較RO水洗膜及RO水配合超音波震盪洗膜，發現二者對過濾液TOC處理效率有些微差異，以後者可得到較高的初始過濾通量，但通量卻衰減較快，推測薄膜表面結構被破壞，以致通量變化差異大。 In this study, batch activated sludge process was used to investigate the differences of degradation of phenolic wastewater by acclimated and non-acclimated sludge. Then, a continuous-flow type of immersed membrane bioreactor (MBR) process was used to investigate the optimum hydraulic retention time (HRT) for the rational design and operation of MBR system in treating high concentration of phenol in wastewater. When low phenol concentration ( 150 mgL-1 ) of wastewater was treated by batch activated sludge process with non-acclimated sludge, the time for phenol biodegradation was longer in lower MLSS concentration and shorter in higher MLSS concentration. There was no significant difference when low strength of phenol in wastewater was decomposed by acclimated sludge. However, it was sown that a significant difference in high strength (2000-3000 mgL-1) of phenol in wastewater. The decomposition rate of phenol was higher with acclimated activated sludge (50 hr) than with non-acclimated sludge (80hr). The result by batch process was important information to treat high concentration of phenol in wastewater by continuous-flow MBR system. The required HRT increased with the high concentration of phenol in wastewater treated by immersive membrane bioreactor, while high MLSS concentration can reduce HRT. However, phenol concentration was increased from 1000 to 2000 mgL-1, the hydraulic retention time is only slightly increased by 1 to 2 hours, thus phenol concentration was increased from 2000 to 3000 mgL-1, hydraulic retention time significantly increased 6-7 hours with higher MLSS concentration. It was assumed that high phenol concentration would inhibit microbial growth due to the toxic effects.After a period of operation by MBR system, the system will produce fouling, off-line cleaning of film will be done. The washing method for membrane, comparison of RO water washed and RO water washed with ultrasonics, the TOC removal efficiency of filtrate was a slightly difference. The higher filtration flux would be obtained when membrane was washed by RO water with ultrasonics. It was suggested that film surface structure was destroyed, resulting in large differences in flux.
