利用銅/鐵/鎂氧化物-生物炭複合材料活化過單硫酸鹽降解BTEX

Abstract

BTEX（苯、甲苯、乙苯與二甲苯）是常見的單環芳香族揮發性有機污染物，廣泛存在於石油產品中，因其毒性與致癌性已被列為優先污染物。為有效處理受 BTEX 污染的地下水，本研究開發並評估以銅、鐵、鎂氧化物與生物炭複合材料（CuFeMgO-BC）活化過單硫酸鹽（PMS）系統之降解效能與機制。研究包含材料特性分析、批次反應實驗、自由基偵測、以及地下水基質成分影響評估。 研究結果顯示CuFeMgO-BC 表面具備多金屬氧化物晶相，並展現優異的 PMS 活化能力。在最佳條件下（PMS 20 mM、CuFeMgO-BC 1 g/L），BTEX 四種化合物於 360 分鐘內去除率達 100%。自由基捕捉實驗與電子順磁共振（EPR）結果證實，硫酸根自由基（SO4•⁻）為主要反應物種，羥基自由基（OH•）與單態氧（1O2）亦參與反應。進一步發現，高劑量的活化劑可能因團聚或自由基消耗而導致效率下降，地下水常見基質如氯離子、硫酸根離子、碳酸氫根離子與腐植酸對降解效率不具明顯抑制作用，然而採用真實地下水時降解效率卻顯著提升，能在30分鐘內達到97-100%的BTEX去除效率。 綜上所述，CuFeMgO-BC 為一具潛力且可穩定活化 PMS 的異相催化材料，適用於實地 BTEX 污染治理，並可因應地下水中多變的基質環境。

BTEX (benzene, toluene, ethylbenzene, and xylene) are common monocyclic aromatic volatile organic compounds present in groundwater contaminated by petroleum products. Due to their toxicity and carcinogenicity, they have been listed as the priority pollutants. To effectively remediate BTEX-contaminated groundwater, this study developed and evaluated a novel system using the Cu/Fe/Mg oxide-biochar composite (CuFeMgO-BC) to activate peroxymonosulfate (PMS) for BTEX degradation. The results demonstrated that CuFeMgO-BC exhibited well-defined multi-metal oxide crystalline structures and possessed an excellent PMS activation capability. Under optimal conditions (PMS = 20 mM, CuFeMgO-BC = 1 g/L), complete removal of BTEX was achieved within 360 min when synthesized groundwater was used. Quenching tests and electron paramagnetic resonance (EPR) analysis confirmed that sulfate radicals (SO4•⁻) were the dominant reactive species, while hydroxyl radicals (OH•) and singlet oxygen (1O2) also partially contributed to the degradation. Excessive dosages of the activator led to reduced efficiency due to particle agglomeration or radical quenching. The presence of typical ions in groundwater, such as chloride, sulfate, bicarbonate, and humic acid, did not significantly inhibit the degradation. Notably, the degradation of BTEX in real groundwater was significantly enhanced, achieving 97-100% within just 30 min. In summary, CuFeMgO-BC is a promising and stable heterogeneous catalyst for PMS activation, offering a high potential for in situ remediation of BTEX-contaminated groundwater.