Landfill leachate has a severe impact on both human health and ecosystem. To address this matter, we report herein a systematic study of a new oxypyrolysis process composed of cracking-combustion coupled reactions over Fe₂O₃@SiO₂-Al₂O₃ catalyst for the removal of organics and ammonia in landfill leachate. Fe₂O₃@SiO₂-Al₂O₃, which contains Brönsted acidity and oxidative sites, is derived from calcination of iron-based MIL-101 nanocast with silica-alumina sol. Fluidized-bed experiments at 339 ℃ reveal the exceptional catalytic activity of Fe₂O₃@SiO₂-Al₂O₃ as manifested by the high removal efficiency of COD (99.2 %) and NH₃-N (95.2 %). The concentration of COD and ammonia nitrogen in the condensed effluent is as low as 18.1 mg/L and 78.9 mg/L respectively, the best performance yet seen in other chemical treatment approaches. The non-condensable gas from the oxypyrolysis reaction only contains CO₂, N₂ and a trace amount of nonmethane hydrocarbons. Insight into oxypyrolysis reaction is provided by thermogravimetric-gas chromatography/mass spectrometry and in-situ infrared spectroscopy. The amorphous SiO₂-Al₂O₃ enables the catalytic cracking of heavy fractions in landfill leachate to small organic molecules, and the Fe₂O₃ nanoparticles realize the catalytic combustion of small organic molecules and ammonia to CO₂, H₂O and N₂. A theoretical analysis of the operation cost estimate shows that the oxypyrolysis reaction is among the most cost-effective treatment methods. Taken together, these findings suggest that the oxypyrolysis is highly applicable for the leachate treatment.

垃圾渗滤液对人类健康和生态系统都有严重影响。为了解决这个问题，我们在此报告了一种新的氧裂解过程的系统研究，该过程由 Fe ₂ O ₃ @SiO ₂ -Al ₂ O ₃催化剂上的裂解-燃烧耦合反应组成，用于去除垃圾渗滤液中的有机物和氨。Fe ₂ O ₃ @SiO ₂ -Al ₂ O ₃含有布朗斯台德酸度和氧化位点，源自铁基 MIL-101 纳米铸件与硅铝溶胶的煅烧。339 ℃流化床实验揭示了Fe ₂ O _{3的优异催化活性}@SiO ₂ -Al ₂ O ₃表现为对 COD (99.2 %) 和 NH ₃ -N (95.2 %) 的高去除效率。冷凝出水的 COD 和氨氮浓度分别低至 18.1 mg/L 和 78.9 mg/L，是迄今为止其他化学处理方法中表现最好的。来自氧裂解反应的不凝气仅含有CO ₂、N ₂和微量的非甲烷烃。通过热重-气相色谱/质谱和原位红外光谱提供对氧解反应的深入了解。无定形SiO ₂ -Al ₂ O ₃能够将垃圾渗滤液中的重质馏分催化裂解为有机小分子，Fe ₂ O ₃纳米颗粒实现有机小分子和氨催化燃烧生成CO ₂、H ₂ O和N ₂。运行成本估算的理论分析表明，氧裂解反应是最具成本效益的处理方法之一。总之，这些发现表明，氧热解非常适用于渗滤液处理。