Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science Chinese Academy of Sciences, Nanjing 210008, China.
J Environ Sci (China). 2021 Mar;101:248-259. doi: 10.1016/j.jes.2020.08.019. Epub 2020 Sep 2.
Nano-FeO embedded in montmorillonite particles (Fe-Mt) were prepared to degrade diethyl phthalate (DEP) with citric acid (CA) under xenon light irradiation. Compared to pristine montmorillonite (Na-Mt), the embedding process increased 14.5-fold of iron content and 1.8-fold of specific surface area. The synthesized Fe-Mt have more oxygen vacancies than FeO nanoparticles (nFeO), which could induce more reactive oxygen species (ROSs) generation in the presence of CA under xenon lamp irradiation. Fe-Mt with CA enhanced photo-assisted degradation of DEP 2.5 times as compared to nFeO with CA. Quenching experiments, electron paramagnetic resonance (EPR) spectroscopy and identification of products confirmed that surface-bound •OH was the main radical to degrade DEP. Common anions (i.e., NO, CO, Cl) and humic acid could compete •OH with DEP and cause slower degradation of DEP. The removal efficiency of DEP was more than 56% with Fe-Mt after three recycles, and the dissolved Fe concentration from Fe-Mt was below 75 μmol/L, indicating Fe-Mt had a good stability as a catalyst. Fe-Mt together with CA appeared to be a promising strategy to remove organic pollutants in surface water, or topsoil under solar irradiation.
纳米-FeO 嵌入蒙脱石颗粒（Fe-Mt）中，在氙灯光照下用柠檬酸（CA）降解邻苯二甲酸二乙酯（DEP）。与原蒙脱石（Na-Mt）相比，嵌入过程使铁含量增加了 14.5 倍，比表面积增加了 1.8 倍。合成的 Fe-Mt 比 FeO 纳米颗粒（nFeO）具有更多的氧空位，这可以在氙灯照射下 CA 的存在下诱导更多的活性氧物质（ROSs）生成。与 nFeO 与 CA 相比，Fe-Mt 与 CA 增强了光助 DEP 的降解，降解效率提高了 2.5 倍。猝灭实验、电子顺磁共振（EPR）光谱和产物鉴定证实，表面结合的 •OH 是降解 DEP 的主要自由基。常见的阴离子（即 NO、CO、Cl）和腐殖酸可以与 DEP 竞争 •OH，导致 DEP 降解速度变慢。Fe-Mt 经过三次循环后，DEP 的去除效率超过 56%，从 Fe-Mt 中溶解的 Fe 浓度低于 75 μmol/L，表明 Fe-Mt 作为催化剂具有良好的稳定性。Fe-Mt 与 CA 一起似乎是一种很有前途的策略，可以去除地表水或太阳照射下的表土中的有机污染物。
