酵母载纳米零价铁催化H₂O₂降解邻苯二甲酸二乙酯的研究

Study on the Degradation of Diethyl Phthalate with H₂O₂ Catalyzed by Yeast Supported Nano Zero-Valent Iron

摘要: 本研究以热处理酵母为载体，以烟叶提取物为还原剂，制备热处理酵母负载纳米零价铁(nZVI@SC_H)，用于催化过氧化氢(H₂O₂)降解邻苯二甲酸二乙酯(DEP)。结果表明，nZVI@SC_H催化H₂O₂降解DEP的反应为准一级反应，其表观活化能E_a为60.63 kJ·mol⁻¹。升温和低pH环境有利于DEP的降解去除。在pH为3~7的范围内，在0.2 g·L⁻¹ nZVI@SC_H的催化作用下，1.5 mM H₂O₂对10 mg·L⁻¹ DEP的去除率均达99.4%以上，残留的DEP低于饮用水中的允许限量。SEM、FT-IR和XPS测定结果表明，热处理酵母表面富含多种含氧官能团，有利于Fe²⁺在其表面负载；烟叶提取物中的还原性物质能抑制Fe⁰的氧化，增加Fe⁰的稳定性。自由基淬灭实验证明，·OH是nZVI@SC_H催化H₂O₂氧化降解DEP的主要活性物质。综上所述，热处理酵母载纳米零价铁能高效催化H₂O₂降解DEP，为邻苯二甲酸酯类污染物的去除提供了新的思路。

Abstract: In this study, heat-treated yeast-supported nano-zero-valent iron (nZVI@SC_H) was prepared using tobacco leaf extract as a reducing agent, and applied to catalyze hydrogen peroxide (H₂O₂) for the degradation of diethyl phthalate (DEP). The results showed that the degradation of DEP by nZVI@SC_H-catalyzed H₂O₂ followed a pseudo-first-order reaction, with an apparent activation energy (Ea) of 60.63 kJ·mol⁻¹. Elevated temperature and low pH favored DEP removal. Within the pH range of 3~7, 1.5 mM H₂O₂ catalyzed by 0.2 g·L⁻¹ nZVI@SC_H achieved a removal rate of over 99.4% for 10 mg·L⁻¹ DEP, with residual DEP below the permissible limit in drinking water. Characterizations by SEM, FT-IR, and XPS confirmed that the heat-treated yeast surface was rich in oxygen-containing functional groups, facilitating the loading of Fe²⁺, while the green components in tobacco leaf extract inhibited the oxidation of Fe⁰ and improved its stability. Free radical quenching experiments demonstrated that ·OH was the main active species in the nZVI@SC_H-catalyzed H₂O₂ oxidation degradation of DEP. In conclusion, heat-treated yeast-supported nano-zero-valent iron efficiently catalyzes H₂O₂ to degrade DEP, providing a new perspective for the removal of phthalate ester pollutants.