Modified biochar with higher electron transport and adsorption capabilities could significantly improve the performance of anaerobic ammonia oxidation (anammox). However, there are few related investigations on the reinforcement of anammox through iron-modified Enteromorpha prolifera biochar (IMEPB). In this study, with the addition of the IMEPB in the anammox system, the enhancing process of anammox performance was studied, the improving feasibility of anammox was evaluated, and the reinforcing mechanism of anammox was elucidated. The results showed that the optimal iron−charcoal ratio (Fe:C) and IMEPB dosage were 1:10 and 10 g L⁻¹, respectively. Under the optimal conditions, when the nitrogen loading rate gradually increased to 0.557 (kg m⁻³ day⁻¹), the nitrogen removal efficiency and nitrogen removal rate of the anammox process supplemented with IMEPB increased by 11%, and the specific anammox activity increased by 23.8%. Compared with the control, the secretion of extracellular polymeric substances (EPS) of anammox bacteria supplemented IMEPB increased by 24.4%, greatly improving the stability of the anammox system. Meanwhile, EPS secretion further promoted the microbial activity of anammox bacteria, achieving a 19% increase in the abundance of Candidatus Brocadia. These findings demonstrate the potential mechanism of IMEPB in improving anammox, provide new insights into recycling E. prolifera, and provide a novel reinforcement strategy for anammox. In the future, adding IMEPB may be a vital measure for the practical application of anammox in coastal areas.

Graphical Abstract

中文翻译：

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一种用铁改性的浒苔生物炭强化厌氧氨氧化过程的新策略

具有更高电子传输和吸附能力的改性生物炭可以显着提高厌氧氨氧化（anammox）的性能。然而，关于通过铁改性的Enteromorpha prolifera生物炭（IMEPB）增强厌氧氨氧化的相关研究很少。本研究通过在厌氧氨氧化体系中加入IMEPB，研究了厌氧氨氧化性能的增强过程，评价了厌氧氨氧化提高的可行性，阐明了厌氧氨氧化的增强机理。结果表明，最佳铁炭比（Fe:C）和IMEPB用量分别为1:10和10 g L ^-1。最优条件下，当氮负荷量逐渐增加至0.557（kg·m ^-3 day^-1 ),辅以IMEPB的厌氧氨氧化工艺脱氮效率和脱氮率提高了11%,厌氧氨氧化比活性提高了23.8%。与对照相比，补充IMEPB的厌氧氨氧化菌胞外聚合物（EPS）分泌量增加了24.4%，大大提高了厌氧氨氧化系统的稳定性。同时，EPS 的分泌进一步促进了厌氧氨氧化菌的微生物活性，使Candidatus Brocadia的丰度增加了 19% 。这些发现证明了 IMEPB 在改善厌氧氨氧化方面的潜在机制，为回收E. prolifera提供了新的见解，并为厌氧氨氧化提供一种新颖的强化策略。未来，添加IMEPB可能是厌氧氨氧化在沿海地区实际应用的重要举措。

图形概要