Abstract:

Anaerobic ammonium oxidation (Anammox) has gained intensive attention in wastewater treatment. Fe²⁺ plays an important role in Anammox system. By continuously increasing the total nitrogen (TN) concentration in the influent, the effects of Fe²⁺ on the nitrogen removal performance and bacterial physiology of Anammox expanded granular sludge blanket reactor (EGSB) were studied. When the concentration of Fe²⁺ increased from 1.00mg/L to 7.50mg/L, the nitrogen removal efficiency and the ability to resist nitrogen load apparently increased. Meanwhile, the concentration of extracellular polymeric substances (EPS) and heme c also increased gradually, reaching the maximum value of 242mg/g VSS and 3.76μmol/mg pro, respectively. The bacterial activity obviously enhanced. When the concentration of Fe²⁺ increased to 10.0mg/L, the nitrogen removal performance of the reactor decreased, the concentration of EPS and heme c also declined, and the bacterial activity reduced. Therefore, addition of 7.50mg/L Fe²⁺ could maximize the nitrogen removal performance of the reactor, improve the bacterial activity, make the granule more compact, as well as promote Anammox sludge sedimentation and aggregation. This work helps the further exploration of the mechanism of Fe²⁺ addition on Anammox system, which is important to cultivate high-performance Anammox sludge and ensures the efficient and stable operation of EGSB reactor.

Key words: Anammox, Fe²⁺, expanded granular sludge blanket reactor（EGSB）, activity, wastewater, bioprocess

摘要：

厌氧氨氧化（Anammox）在污水处理系统中越来越受到重视，Fe²⁺对Anammox系统具有重要作用。通过不断提升进水总氮（TN）浓度，本文研究Fe²⁺对Anammox膨胀颗粒污泥床反应器（EGSB）脱氮性能以及细菌生理变化的影响。当Fe²⁺浓度从1.00mg/L增加到7.50mg/L时，氮去除效果显著增加，抵抗氮负荷的能力明显增强。同时胞外聚合物（EPS）与血红素c浓度也逐渐增加到最大值分别为242mg/g VSS和3.76μmol/mg pro，细菌活性明显提高。随着Fe²⁺浓度继续增加到10.0mg/L，反应器脱氮性能下降，EPS与血红素c含量也随之减少，细菌活性降低。因此，7.50mg/L的Fe²⁺能最大程度增强反应器脱氮性能，提高细菌活性，使颗粒更加致密，促进Anammox污泥沉降和聚集。研究结果有助于深入探索Fe²⁺对Anammox系统的作用机制，对培育高性能Anammox污泥、保证EGSB反应器的高效稳定运行具有重要意义。

关键词: 厌氧氨氧化, 二价铁, 膨胀颗粒污泥床, 活性, 废水, 生物过程