利用光催化法降解嗎啡、甲基安非他命及愷他命

Abstract

近年來化學持久性有機物、藥品與個人護理用品與環境荷爾蒙等新興污染物質存在台灣水體環境，新興污染物之共同特質為法規尚未規範或規範不全、傳統都市污水處理廠無法處理、對人體健康與生態之潛在危害性既深且遠，其對於水環境之影響甚鉅。本研究探討目標管制藥物愷他命、嗎啡及甲基安非他命，於台灣北部淡水河流域中被偵測出最高濃度為206~1240 ng/L(Lin et al.,2010)，此類管制藥物經過污水處理廠處理流程未能完全去除，研究採高級氧化處理程序，廣泛利用之異相光催化處理單元，以期達到降解去除愷他命、嗎啡及甲基安非他命之目的。 異相光催化反應系統，採用傳統波長254 nm UV燈管及波長365 nm UVLED為光催化之紫外光光源，光觸媒則選用TiO2及ZnO進行光催化反應，經由高效液相層析串聯式質譜儀(HPLC-MS/MS)偵測其濃度殘餘率變化，並以異相光催化Langumuir-Hinselwood擬一階反應動力式來描述反應之動力行為，以了解愷他命、嗎啡及甲基安非他命在光催化系統上之特質。 結果顯示，三種管制藥物之趨勢一致，TiO2催化效果較ZnO佳；UV燈管效果較UVLED佳。最佳的處理條件為光強度3.61 mW/cm2波長254 nm 之UV燈管光源，與0.04 g/L劑量之TiO2光觸媒，三種管制藥物於三十分鐘後均達99.9%去除率，擬一階反應速率常數k值亦最佳，愷他命k=1.66 min-1、嗎啡k=6.23 min-1及甲基安非他命k=2.68 min-1。而本實驗嘗試使用之波長365 nm UVLED(光強度1.97 mW/cm2)光源，於TiO2催化劑0.4 g/L最佳添加劑量下，亦可於反應時間三十分鐘後使三種目標管制藥物之去除率均達99.9%，唯其擬一階反應速率常數愷他命(k=0.61 min-1)、嗎啡(k=1.47 min-1)及甲基安非他命(k=0.63 min-1)較UV燈管光源較小，考量其無毒性及較長之生命週期，於反應時間三十分鐘內可達相同去除率，UVLED實為一可發展之替代紫外光光源。研究證實異相光催化技術於降解愷他命、嗎啡及甲基安非他命之可行性。

In recent years, concerns over the emergence of previously unregulated anthropogenic contaminants in natural environment have escalated drastically. Among which chemical persistent organic compounds and environmental hormone pollutants are reported to be incompletely removed during conventional wastewater treatment processes in Taiwan. The presence of these emerging contaminants in the natural environment could potentially cause adverse effects to aquatic organism and human health. For this reason, the purpose of this research is to investigate the efficiency of advanced photocatalytic reaction system in removing three of the most commonly detected controlled substances: morphine, methamphetamines and ketamine in Taiwan. Lin et al., (2010) reported significant quantities of these controlled drugs in Xindian River basin and hospital effluents with concentrations up to 206 ~ 1240 ng /L. The light sources for heterogeneous photocatalytic reaction system in this research are traditional UV light and UVLED with catalyst TiO2 and ZnO. HPLC-MS/MS measures C/Co and Langumuir-Hinselwood pseudo first-order reaction kinetics to describe the dynamic behavior of photocatalytic reaction and to understand the fate of ketamine, morphine and methamphetamine in the photocatalytic system. The results indicate similar degradation trend for all three controlled drugs. TiO2 demonstrates to be more efficient than ZnO as a photo catalyst. UV light is more efficient than UVLED. Wavelength of 254 nm UV light (intensity of 3.61 mW/cm2), and 0.04 g/L dosage of TiO2 is the best operating condition in this study where all the controlled drugs were removed up to 99.9% after 30 minutes of reaction time. Pseudo first-order reaction rate constant for ketamine = 1.66 (min-1), morphine = 6.23 (min-1) and methamphetamine = 2.68 (min-1). In this study, with the dosage of TiO2 at 0.4 g/L and wavelength of 365 nm UVLED light, the oxidation of all three compounds also reached 99.9% removal efficiency after 30 minutes of reaction time with pseudo first-order rate constant of ketamine = 0.61 min-1, morphine = 1.47 min-1 and methamphetamine = 0.63 min–1. As a result, UVLED demonstrates to be a viable alternative photocatalytic light source from the traditional UV light as it produces zero toxic end products and longer life cycle. This study confirms the feasibility of heterogeneous photocatalytic oxidation for ketamine, morphine and methamphetamine.