Evolution of Microbial Community Structure and Denitrifying Functional Microorganisms in the Biological Sponge Iron System
Source abstract
Abstract
With the growing problem of global water pollution, nitrogen pollution has become a key factor affecting aquatic ecosystems and human health. The biological sponge iron system (BSIS) has gained attention as a research hotspot due to its efficient denitrification capability. This study focused on the changes in microbial community structure and the relative abundance and interrelationships of nitrogen cycle-related functional bacteria at different operational stages of the BSIS with a sponge iron (SFe) dosage of 90 g/L. The results showed that as the operation time of the reactor extended, the relative abundance of denitrifying genera such as Saccharimonadales, Arenimonas, and Acinetobacter significantly increased, while the relative abundance of Proteobacteria showed a trend of initial increase followed by a decrease. The relative abundance of nitrifying bacteria exhibited a more complex variation, whereas the abundance of denitrifying bacteria showed a continuous upward trend. In addition, there were complex interrelationships among different denitrifying bacteria, such as a positive correlation between Saccharimonadales and Acetobacteraceae, and a negative correlation between Rhodothermus and Pseudoxanthomonas. This study not only revealed the changes in the relative abundance and interrelationships of microbial communities and nitrogen cycle-related functional bacteria over time with an SFe dosage of 90 g/L, but also provided a new perspective for understanding the intrinsic mechanism of enhanced biological denitrification by sponge iron. These findings are of great significance for optimizing the operating parameters of the BSIS, improving denitrification efficiency, and promoting the practical application of this technology in the field of environmental engineering.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Microbial Fuel Cells and Bioremediation · Microbial Community Ecology and Physiology · Water Treatment and Disinfection
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
College of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China
Funding
Gansu Provincial Department of Science and Technology Natural Science Foundation
References (63)
Show source-provided references
1. Food, water, and energy security in South Asia: A nexus perspective from the Hindu Kush Himalayan region10.1016/j.envsci.2014.01.010 ↗
2. Mabhaudhi, T., Senzanje, A., Modi, A., Jewitt, G., and Massawe, F. (2022). Chapter 13—The Water–Energy–Food nexus as a rallying point for sustainable development: Emerging lessons from South and Southeast Asia. Water-Energy-Food Nexus Narratives and Resource Securities, Elsevier.10.1016/B978-0-323-91223-5.00009-5 ↗
3. Water-lifting aerator coupled with sponge iron-enhanced biological aerobic denitrification to remove nitrogen in low C/N water source reservoirs: Effect and mechanism10.1016/j.envres.2025.121557 ↗
4. Liu, J., Su, J., Ali, A., Wang, Z., Chen, C., and Xu, L. (2021). Role of porous polymer carriers and iron-carbon bioreactor combined micro-electrolysis and biological denitrification in efficient removal of nitrate from wastewater under low carbon to nitrogen ratio. Bioresour. Technol., 321.10.1016/j.biortech.2020.124447 ↗
5. Reduction of nitrate by zero valent iron (ZVI)-based materials: A review10.1016/j.scitotenv.2019.03.317 ↗
6. Iron-Activated Carbon Systems to Enhance Aboriginal Aerobic Denitrifying Bacterial Consortium for Improved Treatment of Micro-Polluted Reservoir Water: Performances, Mechanisms, and Implications10.1021/acs.est.1c05254 ↗
7. Optimizing operation strategy to improve storage of intracellular carbon sources in anaerobic/oxic/anoxic system: Enhanced nitrogen removal by endogenous denitrification10.1016/j.chemosphere.2024.143306 ↗
8. Wang, Y., Wu, Z., Qin, Q., Chen, L., Cai, M., Chen, X., Liu, Y., Su, Z., Fan, X., and Cheng, L. (2025). Nitrogen Removal Performance and Feeding Strategy Optimisation in a Nitritation Denitrification Step-feed Sequencing Batch Reactor System. Biochem. Eng. J.10.1016/j.bej.2025.109761 ↗
9. Aeration management in an oxidation ditch10.1016/j.desal.2009.11.001 ↗
10. Enhancement of denitrification performance with reduction of nitrite accumulation and N2O emission by Shewanella oneidensis MR-1 in microbial denitrifying process10.1016/j.watres.2019.115242 ↗
11. Improvement of the trace metal composition of medium for nitrite-dependent anaerobic methane oxidation bacteria: Iron (II) and copper (II) make a difference10.1016/j.watres.2015.08.040 ↗
12. Enhanced denitrification using iron modified biochar under low carbon source condition: Modulating community assembly, allocating carbon metabolism and facilitating electron transfer10.1016/j.jenvman.2025.125354 ↗
13. Removal of bisphenol A by waste zero-valent iron regulating microbial community in sequencing batch biofilm reactor10.1016/j.scitotenv.2020.142073 ↗
14. Iron scraps packing rapidly enhances nitrogen removal in an aerobic sludge system and the mechanism10.1016/j.scitotenv.2022.159081 ↗
15. Application of sponge iron-carbon to enrich anaerobic ammonia-oxidizing bacteria from sludge mixture and coupled denitrification for degradation of industrial wastewater10.1016/j.jconhyd.2025.104571 ↗
16. Liu, X., Wei, J., Wu, Y., Zhang, J., Xing, L., Zhang, Y., Pan, G., Li, J., Xu, M., and Li, J. (2022). Performances and mechanisms of microbial nitrate removal coupling sediment-based biochar and nanoscale zero-valent iron. Bioresour. Technol., 345.10.1016/j.biortech.2021.126523 ↗
17. Novel characteristics on micro-electrolysis mediated Fe(0)-oxidizing autotrophic denitrification with aeration: Efficiency, iron-compounds transformation, N2O and NO2− accumulation, and microbial characteristics10.1016/j.cej.2019.123409 ↗
18. Microbial reduction of nitrate in the presence of zero-valent iron10.1016/j.scitotenv.2018.07.112 ↗
19. Li, J., Chen, X., Yang, Z., Liu, Z., Chen, Y., Wang, Y.-E., and Xie, H. (2021). Denitrification performance and mechanism of sequencing batch reactor with a novel iron-polyurethane foam composite carrier. Biochem. Eng. J., 176.10.1016/j.bej.2021.108209 ↗
20. Iron Robustly Stimulates Simultaneous Nitrification and Denitrification Under Aerobic Conditions10.1021/acs.est.7b04751 ↗
21. Li, W., Chen, X., Yang, T., Zhu, H., He, Z., Zhao, R., and Chen, Y. (2024). Sponge iron enriches autotrophic/aerobic denitrifying bacteria to enhance denitrification in sequencing batch reactor. Bioresour. Technol., 407.10.1016/j.biortech.2024.131097 ↗
22. Performances and enhanced mechanisms of nitrogen removal in a submerged membrane bioreactor coupled sponge iron system10.1016/j.jenvman.2022.115505 ↗
23. Influencing factors for the Fenton-like of biological sponge iron system and its degradation mechanism of aniline10.1016/j.procbio.2020.11.012 ↗
24. Substantially enhanced degradation of nitrobenzene by biosponge iron system: Process and mechanisms10.1016/j.procbio.2021.05.020 ↗
25. Enhancement of aerobic granulation by zero-valent iron in sequencing batch airlift reactor10.1016/j.jhazmat.2014.07.036 ↗
26. Zhu, H., Li, W., Chen, X., Mu, H., Hu, K., Ren, S., Peng, Y., Zhao, R., and Wang, Y. (2023). Effects of sponge iron dosage on nitrogen removal performance and microbial community structure in sequencing batch reactors. Bioresour. Technol., 368.10.1016/j.biortech.2022.128307 ↗
27. Ahmad, H.A., Ni, S.-Q., Ahmad, S., Zhang, J., Ali, M., Ngo, H.H., Guo, W., Tan, Z., and Wang, Q. (2020). Gel immobilization: A strategy to improve the performance of anaerobic ammonium oxidation (anammox) bacteria for nitrogen-rich wastewater treatment. Bioresour. Technol., 313.10.1016/j.biortech.2020.123642 ↗
28. Evaluation of biological stability and corrosion potential in drinking water distribution systems: A case study10.1007/s10661-008-0343-1 ↗
29. Enhancing 2,6-dichlorophenol degradation and nitrate removal in the nano-zero-valent iron (nZVI) solid-phase denitrification system10.1016/j.chemosphere.2021.132249 ↗
30. Measurement of Diversity10.1038/163688a0 ↗
31. A mathematical theory of communication10.1002/j.1538-7305.1948.tb00917.x ↗
32. Nonparametric estimation of the number of classes in a population
33. Stopping rules and estimation for recapture debugging with unequal failure rates10.1093/biomet/80.1.193 ↗
34. Evolution of microbial community during dry storage and recovery of aerobic granular sludge10.1016/j.heliyon.2019.e03023 ↗
35. Zhang, Z., Fan, Z., Zhang, G., Qin, L., and Fang, J. (2021). Application progress of microbial immobilization technology based on biomass materials. BioResources, 16.10.15376/biores.16.4.8509-8524 ↗
36. Song, Z., Su, X., Li, P., Sun, F., Dong, W., Zhao, Z., Wen, Z., and Liao, R. (2021). Facial fabricated biocompatible homogeneous biocarriers involving biochar to enhance denitrification performance in an anoxic moving bed biofilm reactor. Bioresour. Technol., 341.10.1016/j.biortech.2021.125866 ↗
37. Interpreting 16S metagenomic data without clustering to achieve sub-OTU resolution10.1038/ismej.2014.117 ↗
38. Exposure to nanoplastic induces cell damage and nitrogen inhibition of activated sludge: Evidence from bacterial individuals and groups10.1016/j.envpol.2022.119471 ↗
39. Effects of biochar dosage on treatment performance, enzyme activity and microbial community in aerated constructed wetlands for treating low C/N domestic sewage10.1016/j.eti.2021.101919 ↗
40. Zhao, Q., Chen, K., Li, J., Sun, S., Jia, T., Huang, Y., Peng, Y., and Zhang, L. (2021). Pilot-scale evaluation of partial denitrification/anammox on nitrogen removal from low COD/N real sewage based on a modified process. Bioresour. Technol., 338.10.1016/j.biortech.2021.125580 ↗
41. Effect of intermittent operation and shunt wastewater on pollutant removal and microbial community changes in subsurface wastewater infiltration system10.1016/j.psep.2022.07.020 ↗
42. Enhanced aerobic granulation for treating low-strength wastewater in an anaerobic-aerobic-anoxic sequencing batch reactor by selecting slow-growing organisms and adding carriers10.1016/j.envres.2021.112547 ↗
43. Deng, S., Peng, Y., Zhang, L., and Wu, L. (2020). Advanced nitrogen removal from municipal wastewater via two-stage partial nitrification-simultaneous anammox and denitrification (PN-SAD) process. Bioresour. Technol., 304.10.1016/j.biortech.2020.122955 ↗
44. Important role of Chloroflexi: Improved the cooperation of anammox community under PFOS stress10.1016/j.cej.2024.155950 ↗
45. Zhang, L., Hao, S., Wang, Y., Lan, S., Dou, Q., and Peng, Y. (2021). Rapid start-up strategy of partial denitrification and microbially driven mechanism of nitrite accumulation mediated by dissolved organic matter. Bioresour. Technol., 340.10.1016/j.biortech.2021.125663 ↗
46. Iron-dependent autotrophic denitrification as a novel microbial driven and iron-mediated denitrification process: A critical review10.1016/j.envres.2025.120808 ↗
47. Enhanced biodegradation of thiamethoxam with a novel polyvinyl alcohol (PVA)/sodium alginate (SA)/biochar immobilized Chryseobacterium sp H510.1016/j.jhazmat.2022.130247 ↗
48. Iron-carbon galvanic cells strengthened anaerobic/anoxic/oxic process (Fe/C-A2O) for high-nitrogen/phosphorus and low-carbon sewage treatment10.1016/j.scitotenv.2020.137657 ↗
49. Chen, H., Li, A., Cui, D., Cui, C., and Ma, F. (2019). Evolution of microbial community and key genera in the formation and stability of aerobic granular sludge under a high organic loading rate. Bioresour. Technol. Rep., 7.10.1016/j.biteb.2019.100280 ↗
50. Enantioselective effects of cyflumetofen on microbial community and related nitrogen cycle gene function in acid-soil10.1016/j.scitotenv.2020.144831 ↗
51. Effects of Iron Ore and Biochar Addition on Wastewater Treatment Efficiency, Greenhouse Gas Emissions, and Microbial Community in Subsurface Flow Constructed Wetlands
52. Microbial community and metabolic characteristics evaluation in start-up stage of electro-enhanced SBR for aniline wastewater treatment10.1016/j.jwpe.2021.102489 ↗
53. Plant growth promoting endophyte modulates soil ecological characteristics during the enhancement process of cadmium phytoremediation10.1016/j.jenvman.2024.122206 ↗
54. Enhanced nitrogen removal of constructed wetlands by coupling with the bioelectrochemical system under low temperature: Performance and mechanism10.1016/j.jclepro.2022.131365 ↗
55. The contributions and mechanisms of iron-microbes-biochar in constructed wetlands for nitrate removal from low carbon/nitrogen ratio wastewater10.1039/D0RA03609A ↗
56. High diversity and abundance of putative polyphosphate-accumulating Tetrasphaera-related bacteria in activated sludge systems10.1111/j.1574-6941.2011.01049.x ↗
57. Iron-carbon micro-electrolysis coupled to heterotrophic nitrification aerobic denitrification treating low carbon/nitrogen mariculture wastewater10.1016/j.envres.2025.120796 ↗
58. Biogenic iron oxides for phosphate removal
59. Effect of drained-flooded time ratio on ammonia nitrogen removal in a constructed wetland-microbial fuel cell system by tidal flow operation10.1016/j.jwpe.2021.102450 ↗
60. Wang, Z., Yuan, S., Deng, Z., Wang, Y., Deng, S., Song, Y., Sun, C., Bu, N., and Wang, X. (2020). Evaluating responses of nitrification and denitrification to the co-selective pressure of divalent zinc and tetracycline based on resistance genes changes. Bioresour. Technol., 314.10.1016/j.biortech.2020.123769 ↗
61. Response of microbial nitrogen transformation processes to antibiotic stress in a drinking water reservoir10.1016/j.scitotenv.2021.149119 ↗
62. Effects of low-intensity ultrasound on nitrite accumulation and microbial characteristics during partial nitrification10.1016/j.scitotenv.2019.135985 ↗
63. Characterization of Thauera-dominated hydrogen-oxidizing autotrophic denitrifying microbial communities by using high-throughput sequencing10.1016/j.biortech.2012.10.106 ↗