Three simple structured nitrogen heterocyclic compounds (NHCs), namely indole (ID), benzopyrazole (BP) and benzotriazole (BT), were degraded via wet air oxidation (WAO) in an autoclave-type reactor. The elimination of target pollutants became significant only above 220 °C. The reactivity order of the three substrates was ID > BP > BT. The chemical oxygen demand (COD) removal levels were lower than 70%. Many partial oxidation intermediates were produced, as detected by electrospray ionization–mass spectrometry (ESI-MS). The presence of different anions, such as CO₃²⁻, SO₄²⁻, and PO₄³⁻, had a detrimental effect on the removal performances. On the other hand, Cl⁻ and NO₃⁻ had a beneficial effect on the WAO of the target pollutants. By combining quantum chemistry calculations and ESI-MS analysis, detailed degradation pathways of ID, BP, and BT could be proposed. It was concluded that ring breakage occurred on both the benzene and heterocyclic ring in the initial stage of WAO for all three substrates.

三种简单结构的氮杂环化合物（NHC），即吲哚（ID），苯并吡唑（BP）和苯并三唑（BT），在高压釜型反应器中通过湿空气氧化（WAO）进行降解。仅在220°C以上时，目标污染物的清除才有意义。三种底物的反应顺序为ID> BP> BT。化学需氧量（COD）去除水平低于70％。通过电喷雾电离质谱（ESI-MS）可以检测到许多部分氧化中间体。CO ₃ ^2-，SO ₄ ^2-和PO ₄ ^3-等不同阴离子的存在对去除性能有不利影响。在另一方面，氯^-和NO ₃ ^-对目标污染物的WAO产生了有益的影响。通过结合量子化学计算和ESI-MS分析，可以提出ID，BP和BT的详细降解途径。结论是，在所有三种底物的WAO初始阶段，苯和杂环均发生了环断裂。