Traditional Fenton or Fenton-like oxidation has been widely studied for waste activated sludge dewaterability. However, the narrow pH range (2.0–4.0) and the instabilities of Fe²⁺ and H₂O₂ has hindered its commercial application. Owing to the high alkalinity of anaerobic digestion (AD) sludge, traditional Fenton or Fenton-like oxidation is economically unfeasible for its dewatering. In this study, we successfully demonstrated a novel and feasible method that used nitrilotriacetic acid (NTA)-Fe⁰ combined with CaO₂ (NTA-Fe⁰/CaO₂) at near-neutral pH (∼6.0) (a slight pH adjustment) in which capillary suction time ratio (CST₀/CST) and centrifuged weight reduction (CWR) improved by 6 folds and 42.98 ± 0.37%, respectively, under the optimal conditions. The presence of NTA accelerated the Fe⁰ corrosion, Fe²⁺ stability and turnover between Fe²⁺ and Fe³⁺. As such, Fe⁰ could effectively catalyze CaO₂ to produce hydroxyl radicals (•OH) under near-neutral conditions. Accordingly, various molecular weight hydrophilic compounds in different extracellular polymeric substances fractions were significantly reduced after treatment. The hydrophilic functional groups especially protein molecules were largely reduced. Consequently, the viscosity of sludge and particle size effectively decreased, while the release of bound water, surface charge, flocculation, and flowability of sludge were improved. The cost-benefit analysis further demonstrated the NTA-Fe⁰/CaO₂ treatment has high reusability and stability and is also more economical over the FeCl₃/CaO and Fenton's reagent/CaO treatments. In summary, the NTA-Fe⁰/CaO₂ process is a cost-effective and practically feasible technology for improving AD sludge dewaterability.

传统的Fenton或类Fenton氧化方法已被广泛研究用于废物活性污泥的脱水性。但是，狭窄的pH范围（2.0–4.0）以及Fe ²⁺和H ₂ O ₂的不稳定性阻碍了其商业应用。由于厌氧消化污泥的高碱度，传统的Fenton或类Fenton氧化法在脱水上不可行。在这项研究中，我们成功地证明了一种新颖且可行的方法，该方法在接近中性的pH值（〜6.0）下使用次氮基三乙酸（NTA）-Fe ⁰与CaO ₂（NTA-Fe ⁰ / CaO ₂）结合使用（轻微的pH调节）其中毛细抽吸时间比（CST ₀/ CST）和离心减重（CWR）在最佳条件下分别提高了6倍和42.98±0.37％。NTA的存在加速了Fe ⁰腐蚀，Fe ²⁺稳定性和Fe ²⁺与Fe ³⁺之间的^转变。这样，Fe ⁰可以有效地催化CaO _2。在接近中性的条件下产生羟基自由基（•OH）。因此，处理后，不同细胞外聚合物部分中的各种分子量亲水化合物显着降低。亲水性官能团特别是蛋白质分子被大大还原。因此，污泥的粘度和粒径有效降低，而结合水的释放，表面电荷，絮凝和污泥的流动性得到改善。成本效益分析进一步表明，NTA-Fe ⁰ / CaO ₂处理具有较高的可重复使用性和稳定性，并且比FeCl ₃ / CaO和Fenton试剂/ CaO处理更经济。总之，NTA-Fe ⁰ / CaO ₂ 该工艺是一种提高AD污泥脱水能力的经济有效且切实可行的技术。