Medium chain carboxylates (MCCs) production from sewage sludge (SS) is an economically and environmentally feasible technology for recovering value-added chemicals from SS. To improve MCCs production from SS, Fe (II)-mediated advanced oxidation processes (AOPs) including Fenton oxidation (FO), persulfate oxidation (PO), and combined Fenton-persulfate oxidation (CFP) were adopted to examine their effect on fermentation. Highest total MCCs concentration of 3445.85 mg COD/L was achieved in CFP treated group, followed by PO treated group (2678.78 mg COD/L), control group (2367.72 mg COD/L) and FO treated group (2294.14 mg COD/L). MCCs produced in all groups were dominated by caproate, and all three AOPs treatment promoted longer-chain MCCs (i.e. heptylate and caprylate) production. Microbial analysis showed that genus Romboutsia, Paraclostridium, Clostridium_sensu_stricto_1, norank_f_Anaerolineaceae and Acetobacterium that were positively correlated with MCCs production were significantly enriched in CFP treated group, which contributed to the highest MCCs production in CFP treated group. The functional enzymes analysis showed that both PO and CFO treatment promoted MCCs production by strengthening the fatty acid biosynthesis pathway during the chain elongation (CE) process.

从污水污泥(SS ) 生产中链羧酸盐 (MCC)是一种从 SS 中回收增值化学品的经济和环境可行的技术。为了提高 SS、Fe (II) 介导的高级氧化工艺的 MCC 产量(AOPs) 包括芬顿氧化 (FO)、过硫酸盐氧化 (PO) 和芬顿-过硫酸盐联合氧化 (CFP) 来检验它们对发酵的影响。CFP处理组的总MCCs浓度最高为3445.85 mg COD/L，其次是PO处理组（2678.78 mg COD/L）、对照组（2367.72 mg COD/L）和FO处理组（2294.14 mg COD/L） . 所有组中产生的 MCC 均以己酸为主，所有三种 AOPs 处理均促进了长链 MCC（即庚酸和辛酸）的产生。微生物分析表明，Romboutsia属、Paraclostridium属、 Clostridium_sensu_stricto_1、norank_f_Anaerolineaceae和Acetobacterium与 MCCs 产量呈正相关的蛋白质在 CFP 处理组中显着富集，这导致 CFP 处理组的 MCCs 产量最高。功能酶分析表明，PO 和 CFO 处理都通过在链延长 (CE) 过程中加强脂肪酸生物合成途径来促进 MCCs 的产生。