The aerobic granular sludge (AGS) process had been extensively studied for its simultaneous nitrification and denitrification (SND) capabilities. Iron-carbon (IC) had enhanced AGS nitrogen removal efficiency, but the mechanism remained unclear. In this study, four reactors had been added with 50, 30, 10, and 0 g/L of IC. Total nitrogen removal efficiency increased with IC dosage under the same operation mode. IC enhanced sludge ammonia oxidation rate, denitrification rate, and specific oxygen uptake rate, allowing SND to complete 60 min earlier, potentially reducing wastewater treatment costs. Notably, IC eliminated nitrite accumulation in conventional AGS effluent. IC decreased the abundance of genes and enzyme activities related to NOR expression, while increasing those related to NOS, which may mitigate the potential for nitrous oxide formation by microorganisms. In this study, IC acted as an enzymatic reaction activator, affecting granules more than flocs, with the activity gap gradually decreasing with the IC dosage.

中文翻译：

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铁碳对絮状物和好氧颗粒污泥氮代谢的影响


好氧颗粒污泥 （AGS） 工艺因其同时硝化和反硝化 （SND） 能力而被广泛研究。铁碳 （IC） 提高了 AGS 脱氮效率，但机制尚不清楚。在本研究中，添加了 4 个反应器，分别添加了 50、30、10 和 0 g/L 的 IC。在相同的操作模式下，总脱氮效率随 IC 剂量的增加而增加。IC 提高了污泥氨氧化率、反硝化率和比氧吸收率，使 SND 能够提前 60 分钟完成，从而可能降低废水处理成本。值得注意的是，IC 消除了传统 AGS 流出物中的亚硝酸盐积累。IC 降低了与 NOR 表达相关的基因和酶活性的丰度，同时增加了与 NOS 相关的基因和酶活性，这可能会减轻微生物形成一氧化二氮的可能性。在本研究中，IC 作为一种酶促反应激活剂，对颗粒的影响大于絮凝体，活性间隙随着 IC 剂量的增加而逐渐减小。