A wastewater treatment reactor employing an inverted AAO+IFAS process was designed and constructed. Continuous operation and optimization were conducted using simulated rural domestic wastewater, aiming to enhance denitrification efficiency without external carbon sources and validate the process's applicability. The total effective volume of the reactor's anoxic, anaerobic, and aerobic zones was 154.1 L.Simulated wastewater was introduced into the anoxic and anaerobic zones via point-injection to regulate carbon input. The anoxic zone employed an elliptical flow pattern combined with MBBR media (9% packing density) to enhance denitrification, while the aerobic zone utilized flexible media (20% packing density) to improve nitrification stability. Following a 17-day pre-inoculation period for the fillers prior to operation, and after 52 days of continuous operation with multiple rounds of optimization, the average COD in the effluent over the subsequent 21 days was 38.5 mg/L. During the later stage, the average concentrations of ammonia nitrogen, NO2⁻-N, and NO3- -N concentrations in the later stage were 6.5 mg/L, 0.9 mg/L, and 4.6 mg/L, respectively, achieving a total inorganic nitrogen removal rate of 61.19%.

Junwen Pang, Yuhui Wang, Liuxiao Huang, Xingxiao Lei, Yixiang Yao, Yaping Huang, Xuejun Li, Yuanlong Li, Feng Lai. Study on Inverted AAO+IFAS Process for Treating Simulated Rural Domestic Sewage. International Journal of Frontiers in Engineering Technology (2026), Vol. 8, Issue 1: 14-21. https://doi.org/10.25236/IJFET.2026.080103.

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