以電化學混凝浮除法去除水中非類固醇消炎藥之研究

Removal of nonsteroidal anti-inflammatory drugs from water using electrochemical-coagulation-flotation process with aluminum electrodes

劉于榕(Yu-Jung Liu)

指導教授 ： 胡景堯

臺北醫學大學/公共衛生暨營養學院/公共衛生學系暨研究所/碩士(2013年)

摘要

近年來，非類固醇消炎藥 (Nonsteroidal anti-inflammatory drugs, NSAIDs) 等新興污染物所造成的污染逐漸受到重視，而醫院廢水已被證實為河川及其他水體中藥物可能的主要來源之一。目前仍缺乏一種理想的方法能有效處理醫院廢水裡所含之所有藥物，主因是這些藥物種類太多，其物化及生物性質太複雜，故難以單一種處理機制去除全部藥物。本研究嘗試以電化學混凝浮除法處理含有使用量較多之非類固醇消炎藥─乙醯氨酚 (Acetaminophen)、雙氯芬酸 (Diclofenac)、布洛芬 (Ibuprofen)、酮洛芬 (Ketoprofen)、萘普生 (Naproxen) 之水樣，並就藥物種類特性、溶液的初始酸度、電流負荷量，並額外添加界面活性劑作為捕集劑及起泡劑，以提高藥物吸附量及浮除機制的去除效率等方面進行系統性探討，最後再處理另外嵌入非類固醇消炎藥之實廠廢水，以模擬非類固醇消炎藥在實廠廢水基質下之處理效果。研究結果顯示，在電化學混凝浮除過程中加入陽離子型界面活性劑─溴化十六烷三甲基銨 (Cethyltrimethylam monium bromide, CTAB) 可有效去除疏水性之非類固醇消炎藥 (如雙氯芬酸、布洛芬、酮洛芬、萘普生)，而乙醯氨酚由於其親水性較高而無法被去除。陽離子型界面活性劑 (CTAB) 的理想添加濃度應與藥物初始濃度總和相同才會達到較佳的去除效果，此外，表面張力也會影響藥物的去除效果。未添加陽離子型界面活性劑 (CTAB) 時，在低電流負荷量下，以雙氯芬酸、酮洛芬及萘普生的去除效果較佳，推論此時反應以電混凝沉澱為主要去除機制；反之，在高電流負荷量下，以目標藥物中表面張力最小的布洛芬有較好的去除情形，此一結果指出反應可能以浮除為主要去除機制。當加入陽離子型界面活性劑 (CTAB) 後，電流密度越高，藥物的去除率越好，此時反應以浮除去除為主。而在實廠廢水處理實驗結果顯示，在醫院廢水中的有機雜質可能減少非類固醇消炎藥的去除效果。

關鍵字

電化學混凝浮除法 ； 陽離子界面活性劑 (CTAB) ； 乙醯氨酚 (Acetaminophen) ； 雙氯芬酸 (Diclofenac) ； 布洛芬 (Ibuprofen) ； 酮洛芬 (Ketoprofen) ； 萘普生 (Naproxen)

並列摘要

Nonsteroidal anti-inflammatory drugs (NSAIDs) have recently been recognized as emerging contaminants in the aquatic environment. Due to the large variety of pharmaceutical compounds are used for medical purposes in hospitals, significant concentration of these compounds can be found in hospital wastewaters. However, conventional process in sewage treatment plants have been reported to be an ineffective barrier to these substances because of their complicated properties. In order to develope an promising way to remove the NSAIDs from sewage, a physico-chemical process, electrocoagulation-flotation has been assessed for enhancing the removal of some selected pharmaceuticals- acetaminophen, diclofenac, ibuprofen, ketoprofen and naproxen present in sewage. Cationic surfactant- cethyltrimethylam monium bromide (CTAB) was added during ECF process as a colloctor and frother, to improve drug adsorption and removal efficiency of flotation mechanism. The effect of initial pH, current density and operating time on the process were investigated. Moreover the real hospital wastewater spiked sample was also conducted to modify the real condition.
The results show that NSAIDs can be effectively removed by ECF process with addition of cetyltrimethylammonium bromide (CTAB), but acetaminophen, can not due to it’s high hydrophilic nature. The optimum concentration of CTAB should be equal to the sum of the initial concentration of NSAIDs. Furthermore, the surface tension influenced on the NSAIDs removal. Without the addition of CTAB, at low current intensity, diclofenac, ketoprofen and naproxen had better removal, presumably because the electrocoagulation was the main removal mechanism. On the contrary, at high current intensity, ibuprofen which has the smallest surface tension of the target pharmaceuticals had maximum removal, and this result implied the flotation was the main mechanism. The increase of current intensity leads to the increase of NSAIDs removal with the addition of CTAB and this result reveled the flotation was the main mechanism after the addition of CTAB. Finially, the result of spiked wastewater experiments suggested that the organic impurities in hospital wastewater may lead to the decrease of NSAIDs removal.

並列關鍵字

Electrocoagulation-flotation ； cethyltrimethylam monium bromide (CTAB) ； Nonsteroidal anti-inflammatory drugs (NSAIDs) ； Acetaminophen ； Diclofenac ； Ibuprofen ； Ketoprofen ； Naproxen

參考文獻

1. Carballa, M., F. Omil, and J.M. Lema, Removal of cosmetic ingredients and pharmaceuticals in sewage primary treatment. Water Research, 2005. 39(19): p. 4790-4796.

2. Martins, A.F., C.A. Mallmann, D.R. Arsand, F.M. Mayer, and C.G.B. Brenner, Occurrence of the Antimicrobials Sulfamethoxazole and Trimethoprim in Hospital Effluent and Study of Their Degradation Products after Electrocoagulation. Clean-Soil Air Water, 2011. 39(1): p. 21-27.

3. Ternes, T.A., Occurrence of drugs in German sewage treatment plants and rivers. Water Research, 1998. 32(11): p. 3245-3260.

4. Choi, K., Y. Kim, J. Park, C.K. Park, M. Kim, H.S. Kim, and P. Kim, Seasonal variations of several pharmaceutical residues in surface water and sewage treatment plants of Han River, Korea. Science of the Total Environment, 2008. 405(1-3): p. 120-128.

5. Kolpin, D.W., E.T. Furlong, M.T. Meyer, E.M. Thurman, S.D. Zaugg, L.B. Barber, and H.T. Buxton, Pharmaceuticals, hormones, and other organic wastewater contaminants in US streams, 1999-2000: A national reconnaissance, in Environmental Science & Technology2002. p. 1202-1211.