The effluent quality of a wastewater treatment plant (WWTP) in Hebei Province met the Class I-A standard of "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants"(GB 18918-2002) (COD≤50 mg/L, TN≤15 mg/L, TP≤0.5 mg/L, NH3-N≤8 mg/L). However, under the guidance of energy...