School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou, 730070, PR China; Key Laboratory of Water Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing, 100123, PR China.
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, PR China; State Environmental Protection Key Laboratory of Ecological Effect and Risk Assessment of Chemicals, Chinese Research Academy of Environmental Sciences, Beijing, 100012, PR China.
J Environ Manage. 2022 Nov 15;322:116086. doi: 10.1016/j.jenvman.2022.116086. Epub 2022 Aug 27.
The application of anaerobic ammonium oxidation (Anammox) technology in low-strength wastewater treatment still faces difficult in-situ start-ups and unstable operations. Sponge-iron sludge (R1) was used as a novel inoculum to provide a promising solution. Conventional activated sludge (R0) was used as the control. However, little is known about the feasibility and performance during the start-up and operation of Anammox combined with biological iron and iron bacteria in an iron sludge system. Anammox was successfully started both in R1 (87 days) and R0 (89 days) with a low-strength influent (with a nitrogen loading rate (NLR) of 43.64 ± 0.41 g N/(m⋅d)). During long-term operation, the R0 nevertheless produced higher nitrates (9.7 ± 0.1 mg/L) than expected. In contrast, R1 presented no excess nitrate production (2.1 ± 0.06 mg/L). The total inorganic nitrogen (TIN) removal efficiency increased from 78.2 ± 7.1% in R0 to 86.1 ± 4.3% in R1. The iron sludge in R1 was divided equally into three parts and three different nitrogen-feeding methods were used over the 34 days of operation, as follows: first using a mixture of ammonium (27.15 ± 1.0 mg/L) and nitrite (32.7 ± 1.7 mg/L), then only ammonium (27.15 ± 1.0 mg/L) and lastly only nitrite (32.7 ± 1.7 mg/L) as the influent. R1 was a coupled system composed of Anammox, Feammox, and NO-dependent Fe(II) oxidation (NDFO). The contribution of Feammox and NDFO to TIN removal was 27.1 ± 1.2% and 31.9 ± 0.7%. However, Anammox was the primary nitrogen transformation pathway. X-ray diffraction (XRD) analysis shows that iron hydroxide (Fe(OH)) and iron oxide hydroxide (FeOOH) were generated in R1. The produced Fe(OH) and FeOOH were capable of participating in Feammox and formed a Fe(II)/Fe(III) cycle which further removed nitrogen. Therefore, a highly stable and impressive nitrogen removal performance was demonstrated in the iron sludge Anammox system under the cooperation of biological iron and iron bacteria. The study considered the enrichment of norank_c_OM190, Desulfuromonas, and Thiobacillus and their contribution to the Anammox, Feammox, and NDFO processes, respectively. This study provides a new perspective for the start-up and stable operation of low-strength wastewater Anammox engineering applications.
厌氧氨氧化（Anammox）技术在低强度废水处理中的应用仍然面临着原位启动和不稳定运行的困难。海绵铁污泥（R1）被用作一种新型接种物，提供了一种有前途的解决方案。常规活性污泥（R0）被用作对照。然而，在铁污泥系统中，Anammox 与生物铁和铁细菌联合启动和运行的可行性和性能知之甚少。在低强度进水（氮负荷（NLR）为 43.64±0.41 g N/（m·d））的情况下，R1（87 天）和 R0（89 天）均成功启动了 Anammox。在长期运行过程中，R0 产生的硝酸盐（9.7±0.1 mg/L）高于预期。相比之下，R1 没有产生多余的硝酸盐（2.1±0.06 mg/L）。R0 的总无机氮（TIN）去除效率从 78.2±7.1%提高到 86.1±4.3%。R1 中的铁污泥被平均分成三部分，并在 34 天的运行中使用了三种不同的氮进料方法，如下所示：首先使用氨（27.15±1.0 mg/L）和亚硝酸盐（32.7±1.7 mg/L）的混合物，然后只使用氨（27.15±1.0 mg/L），最后只使用亚硝酸盐（32.7±1.7 mg/L）作为进水。R1 是一个由 Anammox、Feammox 和依赖硝酸盐的 Fe(II)氧化（NDFO）组成的耦合系统。Feammox 和 NDFO 对 TIN 去除的贡献分别为 27.1±1.2%和 31.9±0.7%。然而，Anammox 是主要的氮转化途径。X 射线衍射（XRD）分析表明，R1 中生成了氢氧化铁（Fe(OH)）和氧化铁氢氧化物（FeOOH）。生成的 Fe(OH)和 FeOOH 能够参与 Feammox 并形成 Fe(II)/Fe(III)循环，从而进一步去除氮。因此，在生物铁和铁细菌的协同作用下，铁污泥 Anammox 系统表现出了高度稳定和令人印象深刻的氮去除性能。该研究考虑了 norank_c_OM190、脱硫菌和硫杆菌的富集及其对 Anammox、Feammox 和 NDFO 过程的贡献。本研究为低强度废水 Anammox 工程应用的启动和稳定运行提供了新的视角。
