| 摘要: | 製藥工業在研究開發及生產製造過程中會產生濃度高、變異性大的有機廢水，尤其是原料藥製造廠。當製藥廢液以生物處理程序為核心處理技術進行廢水處理時，可能面臨廢水中含毒性、難分解性物質及濃度高的有機物，進而影響生物處理處理程序的穩定性及出流水品質。為了達到生物處理程序穩定運轉的目標，有必要針對不同製程製藥廢液對生物處理程序的抑制效應進行調查，以決定入料及負荷控管的策略。 本研究參考經濟合作暨發展組織(OECD)及美國環保署(USEPA)所提出的活性污泥呼吸抑制試驗方法，利用活性污泥呼吸儀(respirometer)測量不同製程製藥廢液對活性污泥的50%效應濃度(EC50)，以評估進流廢液對廢水處理廠生物處理程序的毒性或抑制效應。製藥廢液及活性污泥來自南部某製藥公司及其廢水處理廠的薄膜生物反應槽，評估的廢液達64股。研究結果顯示，64股廢液之EC50差異極大，有28股廢液EC50< 25%，可歸類為第一類急毒性廢液；有9股廢液的EC50介於26%~50%，歸為第二類中毒性廢液；2股廢液EC50介於51% ~ 75%，屬第三類毒性廢液；僅1股廢液EC50介於76% ~ 100%，屬第四類微毒性廢液；4股廢液EC50>100%，為第五類理論無毒性廢液；20股廢液對活性污泥不產生抑制，歸為第六類無毒性廢液。64股廢液的化學需氧量(COD)值介於1,100~13,000,000 mg/L，然而廢液的COD與EC50之間並無顯著相關，此結果說明活性污泥的抑制效應不是單純由廢液高的COD濃度造成，廢液中的化學物質性質對活性污泥細菌的毒性或抑制效應影響較鉅。 由上述分析結果可建議，第5及6類廢液對生物處理程序無明顯抑制性，可無所顧慮直接排入生物處理單元進行處理；第2~4類廢液，雖對具不同程度的抑制，但在稀釋後可降低廢水化學物質的濃度及抑制性，因此可排入調勻池根據廢液的EC50進行稀釋後再行生物處理；第1類廢液，由於EC50太低，靠調勻稀釋仍存在生物抑制性或經濟效益低，因此不建議排入廢水處理廠，以避免生物處理單元的操作風險。本研究也針對調勻槽廢水及放流水進行活性污泥呼吸抑制試驗，以期建立一套廢水處理廠之操作緊急應變流程。
The pharmaceutical industry, especially drug manufacturer, would produce high concentrations, large variety of organic wastewaterduring research and development and manufacturing processes. Biological treatment processes are normally employed as a core technology to treat the pharmaceutical wastewater, which could face problems of toxic, non-biodegradable chemicals containing in wastewater that may affect the performance and stability of the biological treatment process, thereby deteriorating the effluent water quality. In order to achieve stable operation of the biological treatment process, it is necessary to investigate the inhibition effect of the variable wastes on microbial activity of the process for suggesting an optimum control strategyfor influent loading. Based on the activated sludge respiration inhibition test proposed by Organization for Economic Co-operation and Development (OECD) and the United States Environmental Protection Agency (USEPA), this study employed a respirometer to determine 50 % effective concentration (EC50) of activated sludge affected by various streams of pharmaceutical wastewater to investigate the toxic impact of high strength influent on biological treatment process. The testing activated sludge and 64 streams of pharmaceutical wastewater were generated and obtained from a pharmaceutical company in southern Taiwan. For the 64 streams, 28 streams of the wastes exhibitedEC50<25% whichwould be classified as theFirst Class - acute toxicity waste; 9 streams of the wastesshowed EC50 ranging from 26% to 50%, being classified as the 2nd Class – medium toxicity waste; 2 streams of the wastes displayed EC50 between 51% and 75% attributing to the3rdClass; only one stream of wastes exhibited EC50 between 76% and 100%, which is classified as a fourth Class –slight toxicity; 4 streams of the wastes showed EC50> 100%, being classified as the 5thClass - theoretical non-toxicity; and 20 streams of the waste showed no inhibition of activated sludge, which is classified as the 6th Class - non-toxicity. Chemical oxygen demand (COD) values of the 64 stream wastes werein the range of 1,100 to13,000,000 mg / L, however, there is no significant correlation between COD and EC50, indicating that the inhibitory effect of activated sludge is not simply caused by high concentration of COD. Toxic characteristics of chemicals contained in the wastewater also play a significant role on inhibitory effect of activated sludge bacteria. The above analysis results suggest that the 5thand 6th Class of the waste streams had no toxic effect on biological wastewater treatment processand could nothing to worry about, which in turn can be directly treated by a biological process. For the 2nd~4th Class streams, because of low to medium toxicity, they should be diluted in the equalized tank before entering to a biological process for treatment. For the 1st Class streams, they are not recommended to be treated by the biological process to avoid causing serious impact on microbial activity of the treatment process. The study also monitored EC50 of activated sludge affected by wastewater in equalization tank and bytreated effluent in order to establish the operational emergency procedures of a wastewater treatment plant. |
