本研究製備球狀形磁性 Fe–TiO₂ 催化劑，並應用於非均相 Photo-Fenton 系統中降解 CMP 廢水中常見之螯合劑 EDTA。CMP 廢水中通常含有奈米級研磨顆粒、金屬成分及多種化學添加物，其中 EDTA 因具有良好金屬螯合能力，可與金屬離子形成穩定錯合物，使其不易藉由傳統混凝、沉澱或過濾程序有效去除。若未能在前處理階段先降低此類溶解性有機物含量，可能增加後續膜分離系統之有機負荷，造成膜污染或通量下降，進而影響處理水回收再利用之可行性。 本研究以前驅物經水熱反應、還原處理及煅燒程序製備磁性 Fe–TiO₂ 催化劑，並進行材料特性分析。SEM 與 TEM 結果顯示，所製備之 Fe–TiO₂ 具有球狀形貌；EDS 與 XPS 分析結果顯示材料中可偵測到 Ti、O 與 Fe 等元素，表示鐵成分已成功導入 TiO₂ 材料中。BET 分析結果顯示，Fe–TiO₂ 之比表面積為 10.15 m²/g，總孔體積為 0.0236 cm³/g，BJH 平均孔徑為 12.17 nm，顯示材料具有中孔結構。SQUID 分析結果顯示，Fe–TiO₂ 之飽和磁化量為 4.94 emu/g，雖然低於自製 Fe₃O₄ 之 55.21 emu/g，但仍保有磁性反應，顯示其具有後續磁性分離與回收之潛力。 在 Photo-Fenton 實驗中，本研究以 EDTA 作為目標污染物，先以批次式實驗探討不同反應系統與操作參數對降解效率之影響。首先，不同反應系統比較結果顯示，Fe–TiO₂/H₂O₂/UV 系統具有最佳 EDTA 降解效果，其反應速率常數為 0.10767 min⁻¹，分別約為 TiO₂/H₂O₂/UV 系統之 4.9 倍及 H₂O₂/UV 系統之 7.3 倍，表示 Fe–TiO₂ 搭配 H₂O₂ 與 UV 照射可明顯提升 EDTA 降解效率。進一步針對 Fe–TiO₂/H₂O₂/UV 系統進行操作參數探討，結果顯示催化劑添加量、pH 值、H₂O₂ 添加量、Fe/Ti 莫耳比、NaBH₄ 添加量及光照條件皆會影響 EDTA 降解效果；由各操作參數實驗結果可知，催化劑添加量 0.05 g/L、pH 5.37、H₂O₂ 添加量 100 ppm、Fe/Ti 莫耳比 0.1、NaBH₄ 添加量 1.0 g 及光照強度 9.5 mW 為本研究中較適合之操作條件，並作為後續多循環實驗之主要反應條件。 此外，EPR 分析結果顯示，TiO₂ 與 Fe–TiO₂ 在 H₂O₂ 與 UV 照射條件下皆可觀察到 DMPO 捕捉 ·OH 後之特徵 1:2:2:1 四重峰，表示反應過程中有 ·OH 生成。其中 Fe–TiO₂ 系統之 ·OH 訊號明顯高於 TiO₂，且隨反應時間增加而逐漸增強，說明 Fe–TiO₂ 有助於提升系統中活性氧化物種之生成。 本研究進一步以含 EDTA 與偏矽酸鈉之模擬 CMP 廢水進行多循環 Photo-Fenton 實驗，以評估磁性 Fe–TiO₂ 催化劑之重複使用性。結果顯示，第一循環之反應速率常數為 0.01700 min⁻¹，經五次循環後 Fe–TiO₂ 催化劑仍具有 EDTA 降解能力，其中第五循環之反應速率常數為 0.01155 min⁻¹，約為第一循環之 68%。雖然反應速率常數隨循環次數增加而逐漸下降，但整體結果顯示磁性 Fe–TiO₂ 催化劑仍具有一定重複使用性與回收再利用潛力。綜合上述結果，本研究所製備之球狀形磁性 Fe–TiO₂ 催化劑可應用於 CMP 廢水中 EDTA 之前處理降解，並具有氧化降解、磁性分離及回收再利用之應用潛力。;In this study， spherical magnetic Fe–TiO₂ catalysts were prepared and applied in a heterogeneous Photo-Fenton system for the degradation of EDTA， a common chelating agent found in CMP wastewater. CMP wastewater generally contains nanoscale abrasive particles， metal components， and various chemical additives. Among these additives， EDTA exhibits strong metal-chelating ability and can form stable complexes with metal ions， making it difficult to remove effectively through conventional coagulation， precipitation， or filtration processes. If such dissolved organic compounds are not reduced during the pretreatment stage， the organic loading of subsequent membrane separation systems may increase， potentially causing membrane fouling or flux decline and thereby affecting the feasibility of water recovery and reuse. In this study， magnetic Fe–TiO₂ catalysts were synthesized from precursors through hydrothermal reaction， reduction treatment， and calcination， followed by material characterization. SEM and TEM results showed that the prepared Fe–TiO₂ exhibited a spherical morphology. EDS and XPS analyses confirmed the presence of Ti， O， and Fe in the material， indicating that iron was successfully incorporated into the TiO₂ structure. BET analysis showed that Fe–TiO₂ had a specific surface area of 10.15 m²/g， a total pore volume of 0.0236 cm³/g， and a BJH average pore diameter of 12.17 nm， indicating that the material possessed a mesoporous structure. SQUID analysis showed that the saturation magnetization of Fe–TiO₂ was 4.94 emu/g， which was lower than that of the self-prepared Fe₃O₄ at 55.21 emu/g. Nevertheless， Fe–TiO₂ still exhibited magnetic response， suggesting its potential for subsequent magnetic separation and recovery. In the Photo-Fenton experiments， EDTA was selected as the target pollutant， and batch experiments were first conducted to investigate the effects of different reaction systems and operating parameters on degradation efficiency. The comparison of different reaction systems showed that the Fe–TiO₂/H₂O₂/UV system achieved the highest EDTA degradation performance， with a reaction rate constant of 0.10767 min⁻¹， which was approximately 4.9 times and 7.3 times higher than those of the TiO₂/H₂O₂/UV and H₂O₂/UV systems， respectively. These results indicate that the combination of Fe–TiO₂， H₂O₂， and UV irradiation significantly enhanced EDTA degradation efficiency. Further optimization of the Fe–TiO₂/H₂O₂/UV system showed that catalyst dosage， pH， H₂O₂ concentration， Fe/Ti molar ratio， NaBH₄ dosage， and light irradiation conditions all affected EDTA degradation. Based on the results of the operating parameter experiments， a catalyst dosage of 0.05 g/L， pH 5.37， H₂O₂ concentration of 100 ppm， Fe/Ti molar ratio of 0.1， NaBH₄ dosage of 1.0 g， and light intensity of 9.5 mW were identified as suitable operating conditions in this study and were used as the main reaction conditions for subsequent multi-cycle experiments. In addition， EPR analysis showed that both TiO₂ and Fe–TiO₂ produced the characteristic 1:2:2:1 quartet signal of DMPO–·OH under H₂O₂ and UV irradiation， indicating the generation of ·OH during the reaction. The ·OH signal intensity in the Fe–TiO₂ system was significantly higher than that in the TiO₂ system and gradually increased with reaction time， suggesting that Fe–TiO₂ facilitated the generation of reactive oxygen species in the system. Furthermore， multi-cycle Photo-Fenton experiments were conducted using simulated CMP wastewater containing EDTA and sodium metasilicate to evaluate the reusability of the magnetic Fe–TiO₂ catalyst. The results showed that the reaction rate constant in the first cycle was 0.01700 min⁻¹. After five cycles， the Fe–TiO₂ catalyst still retained EDTA degradation ability， with a reaction rate constant of 0.01155 min⁻¹ in the fifth cycle， corresponding to approximately 68% of that in the first cycle. Although the reaction rate constant gradually decreased with increasing cycle number， the overall results demonstrated that the magnetic Fe–TiO₂ catalyst possessed a certain degree of reusability and potential for recovery and reuse. Overall， the spherical magnetic Fe–TiO₂ catalyst prepared in this study can be applied for the pretreatment degradation of EDTA in CMP wastewater and shows potential for oxidative degradation， magnetic separation， and recovery and reuse applications.
