UV/PAA光催化程序去除廢水中PPCPs效能之研究

Abstract

藥物與個人照護產品（PPCPs）由於使用量大、排放廣泛且具化學穩定性，近年來已成為水環境中重要的微量污染物之一。這些化合物常見於家庭、醫療及農牧業廢水中，最終進入污水處理系統及自然環境。然而，傳統污水處理廠主要用於去除有機物、懸浮固體及病菌，對PPCPs等新興污染物的去除效果有限。導致PPCPs可能長期累積於環境中，造成潛在的生態及健康風險。 高級氧化程序（AOPs）透過產生高反應性自由基，可用於難降解有機污染物的處理。其中，過氧乙酸（PAA）因其強氧化能力、良好殺菌效果、及產生較少有害副產物，可被當作氯的替代品。PAA為一種有機過氧酸，可透過醋酸與過氧化氫反應生成。美國環保署（USEPA）已於2012年核准其用於污水消毒。此外，PAA在水中穩定，較不受污水基質影響，但單獨使用時難以有效降解如PPCPs等化合物，需藉由紫外線（UV）活化進一步產生羥基自由基（•OH）及過氧自由基（CH₃C(O)O•）等高反應性自由基以提升降解效能。 本研究以七種代表性PPCPs（止痛藥 Acetaminophen、Ibuprofen，抗糖尿病藥 Gliclazide、Glimepiride，精神科藥物 Diazepam、Alprazolam、Clonazepam）為目標污染物，評估UV/PAA程序在Milli-Q純水及二級出流水中之降解效果，並與UV/H₂O₂與UV/Cl₂等常見AOP系統進行比較。 結果顯示，PAA單獨使用對PPCPs去除效果不佳（去除率皆<10%），UV單獨照射可提升部份降解效率，而UV/PAA於10分鐘內可將Glimepiride與Gliclazide去除率分別達到79%與77%。Ibuprofen與Acetaminophen也有中等去除效果（35%與43%）。UV/Cl₂雖然降解效率最高，但相較於其他兩者處理程序，其可能生成消毒副產物（如THMs濃度>30 μg/L），而UV/PAA則顯著降低副產物產生風險。 本研究結果表明，UV/PAA為一種兼具效能與環保性的AOP，對於去除污水中的PPCPs具有良好的穩定性及效率，可作為氯處理的替代方案，實現更安全與永續的水資源管理。

Pharmaceuticals and personal care products (PPCPs) have been increasingly detected in the aquatic environment due to their widespread use and persistent chemical properties. However, conventional wastewater treatment plants (WWTPs), primarily designed to remove organic pollutants, pathogens, and suspended solids, lack the capability to effectively degrade PPCPs. As a result, advanced oxidation processes (AOPs) have been proposed for their ability to generate highly reactive radicals to mineralize those contaminants. Peracetic acid (PAA) is a promising alternative oxidant of chlorine due to its strong oxidative potential, disinfection ability, and minimal formation of toxic disinfection by-products (DBPs). However, PAA alone is insufficient for PPCP removal and requires activation, such as ultraviolet (UV) irradiation. This study evaluates the degradation of seven PPCPs using UV/PAA, UV/H₂O₂, and UV/chlorine in both Milli-Q water and secondary-treated effluent. The results showed that PAA alone was ineffective in degrading PPCPs, with <10% removal. Under UV/PAA treatment, GMP and GCZ were removed by 79% and 77%, respectively, while IBU and ACE reached 35% and 43% removal. UV/chlorine had the highest removal efficiencies for most chemicals, but also generated high concentrations of DBPs (e.g., THMs >30 µg/L). In field wastewater, the removal efficiency of UV/PAA was observed similarly to UV/chlorine, which was significantly affected by the matrix in wastewater. These results suggest UV/PAA is an effective and safer alternative to chlorine-based AOPs for PPCP removal in wastewater treatment.