Wastewater treatment plants (WWTPs) are now facing the challenges of high cost, high energy consumption, while effluent quality is relatively poor with total nitrogen concentration exceeding the requirement of reuse. This study investigated the performance of contaminants removal, especially nitrogen (N) by a hybrid oxidation ditch (H-OD) which is based on the theory of integrated fixed-film activated sludge (IFAS) under different control factors. The aeration rate, return ratio and hydraulic loading were controlled at 0.4 m³/h, 100% and 0.55 m³/m³·h respectively as the optimized control parameter values. Under the optimized conditions, the effluent concentration of COD and NH₄⁺-N were 35.8 mg/L, 1.04 mg/L, respectively, while the suspended solid (SS) was below 10 mg/L. The average removal rate of TN was 72.8%, and simultaneous nitrification and denitrification (SND) was achieved at 42.7%. Besides, when the C/N ratio was maintained from 2.12 to 5.56, the complete nitrification and denitrification was obtained. The results showed that the H-OD was suitable for nitrogen removal and SND was very attractive for practical engineering applications.

废水处理厂（WWTP）现在面临着高成本，高能耗的挑战，而出水水质相对较差，总氮浓度超过了再利用的要求。这项研究调查了混合氧化沟（H-OD）去除污染物的性能，尤其是氮（N），混合氧化沟基于在不同控制因素下集成固定膜活性污泥（IFAS）的理论。作为最佳的控制参数值，将通气量，回流比和水力负荷分别控制在0.4m ³ / h，100％和0.55m ³ / m ³ ·h。在优化条件下，COD和NH ₄ ⁺ -N的出水浓度分别为35.8  mg / L，1.04 毫克/升，而悬浮固体（SS）低于10 毫克/升。TN的平均去除率为72.8％，同时硝化和反硝化（SND）达到42.7％。此外，当C / N比保持在2.12至5.56时，获得了完全的硝化和反硝化。结果表明，H-OD适合脱氮，而SND在实际工程应用中非常有吸引力。