The extreme pH, high color, and poor biodegradability of refractory wastewater have severe impacts on its biological treatment. To address this issue, an advanced Fe-Cu process with redox reaction and spontaneous coagulation was investigated and applied for pilot-scale (wastewater flow rate of 2000 m³·day⁻¹) pretreatment of separately discharged acidic chemicals and alkaline dyeing wastewater. The advanced Fe-Cu process had five functions: (1) increasing the pH of chemical wastewater to 5.0 and above, with an influent pH of approximately 2.0; (2) transforming refractory organics of chemical wastewater with 10.0% chemical oxygen demand (COD) and 30.8% color removal, thereby enhancing the ratio of biological oxygen demand after five days (BOD₅) to COD (B/C) from 0.21 to 0.38; (3) neutralizing the pH of the pretreated chemical wastewater for coagulation application with alkaline dyeing wastewater to avoid adding alkaline chemical; (4) achieving average nascent Fe(II) concentrations of 925.6 mg∙L⁻¹ using Fe-Cu internal electrolysis for mixed wastewater coagulation, resulting in an average of 70.3% color removal and 49.5% COD removal; (5) providing more efficient COD removal and B/C enhancement than FeSO₄∙7 H₂O coagulation while avoiding secondary pollution. The green process offers an effective, easy-implemented solution for the pretreatment of separately discharged acidic and alkaline refractory wastewater.

难降解废水pH值极端、色度高、可生化性差，对其生物处理造成严重影响。为了解决这个问题，研究了一种具有氧化还原反应和自凝作用的先进铁铜工艺，并将其应用于中试规模（废水流量为2000 m 3 ^· day ^-1）单独排放的酸性化学品和碱性印染废水的预处理。先进的铁铜工艺有五个作用：（1）将化工废水的pH值提高到5.0以上，进水pH值约为2.0；(2)转化化工废水难降解有机物，化学需氧量（COD）10.0%，脱色率30.8%，从而提高五天后生物需氧量比例（BOD ₅) 至 COD (B/C) 从 0.21 至 0.38；(3)将预处理后的混凝用化学废水与碱性印染废水进行pH中和，避免添加碱性化学品；（4）利用Fe-Cu内部电解混合废水混凝，初生Fe(II)平均浓度达到925.6 mg∙L ^-1，平均去除颜色70.3%，COD去除率49.5%；(5)比FeSO ₄ ∙7 H ₂ O混凝更有效地去除COD和增强B/C，同时避免二次污染。该绿色工艺为单独排放的酸性和碱性难降解废水的预处理提供了有效且易于实施的解决方案。