探討階段式厭氧薄膜流體化床在不同水力停留時間去除NSAIDs與Carbamazepine的成效

Abstract

應著科學及醫學的進步，藥物被大量地使用來預防或治療疾病，人們食用藥物後隨著人體代謝排泄出體外，最後進入污水處理系統並排放至承載水體中，但傳統的污水處理系統未能完全去除這些藥物，而終在環境中四處流佈，甚至威脅飲用水的品質。 過去研究顯示生物厭氧流體化床串聯厭氧薄膜反應槽 (Stage anaerobic fluidized membrane bioreactor, SAF-MBR) 不僅能有效處理低強度生活污水，亦能去除污水中的某些微量污染物，本研究則更深入探討SAF-MBR去除微量污染物之機制與HRT變化的關係。以實驗級SAF-MBR處理真實生活污水，並另外添加藥物，種類包含三種非類固醇抗發炎劑 (NSAIDs)，即布洛芬 (Ibuprofen, IBP)、萘普生 (Naproxen, NPX)、雙氯芬酸 (Diclofenac, DCF)，及另一種精神類藥物卡馬西平 (Carbamazepine, CBZ)。反應槽穩定操作超過400天並分別在兩段HRT下採樣分析，結果顯示Naproxen在經SAF-MBR處理後可受厭氧微生物降解，有達80%的去除效果，並且在兩段HRT下去除效率無明顯變化；而另三種生物降解作用較不理想甚至出現負數的去除效率，三者分別是Ibuprofen 29% 、Carbamazepine 18%、Diclofenac -83%，在HRT改變時亦只有Carbamazepine的去除效率稍微傾向正相關，其餘皆無明顯關聯。另外懸浮固體物萃取試驗證明污水中之固體物會吸附藥物，在微生物無法分解藥物的前提下，固體物解體後藥物會再度於薄膜槽中釋出，此現象可能是導致出流水藥物濃度較進流高之原因。

Due to the advances of medicine science and technology, drugs are widely used to prevent or cure diseases. After drugs were ingested into human body, it excreted out human body through the metabolism process. The excretions were then entered sewage treatment plant which further discharged to water bodies. However, conventional sewage treatment cannot completely remove the emerging contaminants, the drugs scatter around the environment, and even deteriorate quality of drinking water. Previous studies shown that the SAF-MBR (Stage anaerobic fluidized membrane bioreactor) not only could treat low strength wastewater effectively but also remove some kinds of emerging contaminant. The objective of this study was to investigate the mechanism of removing the trace pollutants and the influences when the HRT changed. In this study, a lab scale SAF-MBR was used to treat domestic wastewater, and spiked four target compounds in influent. Out of four kind of target compound, three of them are non-steroid anti-inflammatory drug: ibuprofen, naproxen and diclofenac and another one of them is psychiatric drugs: carbamazepine. The SAF-MBR system had run stability for over 400 days, and the concentration of the drugs was analyzed at two different HRTs. The results shown that naproxen could be degraded by anaerobic microorganism in which the removal efficiency had reached 80%, and the removal efficiency show no obvious different in two HRTs. On the contrary, the removal efficiency of ibuprofen, carbamazepine and diclofenac were 29%, 18% and -83% respectively. Negative removal efficiency might be due to the adsorbed potential of suspended solid in influent and reactor. The extracted test indicated the adsorbed potential of suspended solid. Thus when the solid disintegrated, drugs attached on suspended solid release into the membrane reactor. It was the reason why the effluent concentration would be higher than influent. The removal efficiency of ibuprofen and diclofenac shown no related with HRTs while removal efficiency of carbamazepine had positive correlation with HRTs.