AGS technology has been studied for decades, and many successful experimental research approaches and full-scale processes have been proposed. However, a precise, comprehensive understanding of the granulation mechanism remains lacking. In this study, sequencing batch reactors were partially inoculated with (S1) or without AGS (S2) to explore aerobic granulation performance in simulative low-strength wastewater. The COD, NH₄⁺-N removal efficiency and SND rate were 91.61%, 92.47%, and 84%, respectively, in S1 and higher in this reactor than in S2 (86.76%, 85.21%, and 75%, respectively), indicating the superiority of partial inoculation with AGS. The ratios of P release/NaAc uptake both increased to nearly 0.250, revealing the robust capacity for phosphorus enrichment. Moreover, the increment of EPS content in S2 (31.73 mg/g MLSS) was 47% higher than that in S1 (21.54 mg/g MLSS) and was contributed mainly by PS, which increased to 30.17 mg/g MLSS (S2). These findings indicated active sludge for granulation was more sensitive to the ambient conditions, and secrete greater PS. FTIR and 3D-EEM revealed that numerous hydroxyl groups were assembled within EPS upon granulation, and humic acid-like substances first increased and then decreased over the operation, implying robust cohesion and positive microbial activities. Microbial community analysis demonstrated that Paracoccus and unclassified_Cytophagales dominated in both reactors, accounting for 29.42% and 10.87%, respectively, of the community in S1 and 26.62% and 18.54%, respectively, of the community in S2. Metabolic pathway analysis revealed enhancement of microbial metabolism, cellular processes, and signaling pathways, such as methanol oxidation, methylotrophy, and nitrite denitrification pathways.

AGS 技术已经研究了几十年，并提出了许多成功的实验研究方法和全尺寸工艺。然而，仍然缺乏对造粒机制的精确、全面的理解。在本研究中，序批式反应器部分接种（S1）或不接种 AGS（S2），以探索模拟低浓度废水中的好氧造粒性能。COD，NH ₄ ⁺-N去除率和SND率在S1中分别为91.61%、92.47%和84%，且高于S2（分别为86.76%、85.21%和75%），说明部分接种的优越性与AGS。P 释放/NaAc 吸收的比率均增加到接近 0.250，表明富集磷的能力很强。此外，S2（31.73 mg/g MLSS）中EPS含量的增量比S1（21.54 mg/g MLSS）高47%，主要由PS贡献，增加到30.17 mg/g MLSS（S2）。这些发现表明用于造粒的活性污泥对环境条件更敏感，并分泌更多的 PS。FTIR 和 3D-EEM 显示在造粒时 EPS 内组装了大量羟基，并且腐殖酸类物质在操作过程中先增加后减少，意味着强大的凝聚力和积极的微生物活动。微生物群落分析表明Paracoccus和unclassified_Cytophagales在两个反应器中占主导地位，分别占 S1 群落的 29.42% 和 10.87%，分别占 S2 群落的 26.62% 和 18.54%。代谢通路分析揭示了微生物代谢、细胞过程和信号通路的增强，如甲醇氧化、甲基营养和亚硝酸盐反硝化通路。