Recently, the short-chain fatty acids (SCFAs) production with carbon recovery from waste activated sludge has received increasing attention. Despite that numerous approaches have been investigated, the divalent cation chelation towards enhancing anaerobic fermentation and the carbon migration fates has been rarely reported. This work attempted to chelate structural divalent cations from sludge flocs by sodium pyrophosphate (SP) at the dosages of 0-0.6 g/g SS, facilitating sludge disintegration and hydrolysis with particulate organic matters solubilization. At the optimal SP dosage of 0.4 g/g SS, the chemical oxygen demand (COD) and carbon source content in sludge solid were reduced by 45.24% and 35.50% within 1-day treatment, leading to considerable sludge hydrolysis and carbon release performances with soluble COD/total COD of 23.21% and carbon release rate of 26.94% in 2-day anaerobic fermentation, respectively. Numerous SCFAs of 237.43 mg COD/g VSS were produced by 4-day anaerobic fermentation, with the overall carbon recovery rate of 21.19%, which were dominantly composed by acetate and propionate. Meanwhile, the SP-inhibited biogas generation also contributed to SCFAs accumulation. The divalent cation chelation obviously improved rate constant and equilibrium performances of anaerobic fermentation process, which were 1.81-5.21 and 1.36-2.82 times higher than those without SP, respectively. The carbon migration pattern was proposed by interphase carbon source balance and the mechanism was also illustrated. The crucial novelty was to propose an innovative and economic sludge hydrolysis pattern by divalent cation chelation towards improving carbon recovery.

最近，从废弃活性污泥中回收碳生产短链脂肪酸（SCFAs）受到越来越多的关注。尽管已经研究了许多方法，但很少有关于增强厌氧发酵和碳迁移命运的二价阳离子螯合的报道。这项工作试图通过焦磷酸钠 (SP) 在 0-0.6 g/g SS 的剂量下螯合污泥絮凝物中的结构二价阳离子，促进污泥分解和水解，同时溶解颗粒有机物。在 0.4 g/g SS 的最佳 SP 用量下，处理 1 天后污泥固体中的化学需氧量 (COD) 和碳源含量分别降低了 45.24% 和 35.50%，从而使污泥水解和碳释放性能显着提高可溶性 COD/总 COD 为 23。2天的厌氧发酵分别为21%和26.94%的碳释放率。经过4天的厌氧发酵，产生了237.43 mg COD/g VSS的大量SCFAs，总碳回收率为21.19%，主要由乙酸盐和丙酸盐组成。同时，SP 抑制沼气的产生也有助于 SCFAs 的积累。二价阳离子螯合显着提高了厌氧发酵过程的速率常数和平衡性能，分别比没有SP的高1.81-5.21和1.36-2.82倍。通过间期碳源平衡提出了碳迁移模式，并阐明了其机制。关键的新颖之处在于通过二价阳离子螯合提出了一种创新且经济的污泥水解模式，以提高碳回收率。