The high water content of sewage sludge increases the processing costs and hampers its further disposal. Fenton technology has proven to be efficient and been widely used to enhance sludge dewaterability, but it usually needs acidification and subsequent neutralization, thus consuming a lot of chemicals. It’s well documented that hydroxyl radicals produced in various Fenton or Fenton-like reactions play a crucial role in sludge dewatering. Based on the latest study, Cu⁺ and Cu⁺/H₂O₂ pretreatments for the enhanced dewaterability of sludge without extra pH adjustment were proposed. Results showed that Cu⁺ with and without H₂O₂ can significantly improve the dewatering performance of sludge, which was ascertained by a capillary suction time (CST) reduction rate of about 80 %. The proteins and polysaccharides in tightly-bound extracellular polymeric substance (TB-EPS) were decreased, while increased in soluble extracellular polymeric substance (S-EPS). In addition, a hydrophobic and porous surface was formed, and zeta potential increased after conditioned. These changes may release bound water and thus improve sludge dewaterability. The results of electron spin resonance and scavenging tests signaled that the Cu³⁺ was mainly accountable for the dissolution of EPS, rather than the hydroxyl radicals (OH). Our results substantiate and untangle a distinct reinforcement mechanisms for sludge dewatering by high valent copper (Cu³⁺). This study demonstrates for the first time that Cu³⁺ plays an important role in sludge dewatering, which has long been credited to hydroxyl radicals. It also urges re-evaluation of the Fenton(-like) system for sludge dewatering, given that Cu³⁺ could also cause potential oxidative destruction of EPS compared with reactive oxygen species.

污水污泥含水量高，增加了处理成本，阻碍了其进一步处置。芬顿技术已被证明是有效的，并被广泛用于提高污泥脱水能力，但它通常需要酸化和随后的中和，因此消耗大量化学品。有据可查的是，在各种芬顿或类芬顿反应中产生的羟基自由基在污泥脱水中起着至关重要的作用。基于最新研究，提出了无需额外调节 pH 值即可增强污泥脱水性能的Cu ⁺和 Cu ⁺ /H ₂ O _{2预处理方法。}结果表明，Cu ⁺含和不含 H ₂ O ₂可以显着提高污泥的脱水性能，毛细管吸入时间 (CST) 减少约 80% 可以确定这一点。紧密结合的细胞外聚合物（TB-EPS）中的蛋白质和多糖减少，而可溶性细胞外聚合物（S-EPS）中的蛋白质和多糖增加。此外，形成疏水和多孔表面，调节后 zeta 电位增加。这些变化可能会释放结合水，从而提高污泥的脱水能力。电子自旋共振和清除测试的结果表明，Cu ³⁺主要负责 EPS 的溶解，而不是羟基自由基（哦）。我们的结果证实并阐明了高价铜 (Cu ³⁺ ) 对污泥脱水的独特强化机制。这项研究首次证明了 Cu ³⁺在污泥脱水中起着重要作用，这一直被归功于羟基自由基。它还敦促重新评估用于污泥脱水的芬顿（类）系统，因为与活性氧相比，Cu ^{3+也可能导致 EPS 的潜在氧化破坏。}