Elemental iron provides a viable strategy to improve the denitrification efficiency by expediting electron transport. However, the roles of magnetic iron powder (FeO) on mixotrophic denitrification remains unknown. In this study, the intra/extracellular electron transfer (IET/EET) and microbial metabolism mechanisms were explored in a FeO-mediated sulfide-autotrophic and heterotrophic denitrification system. The results showed that FeO promoted the formation of dense clump structure with filamentous cross-linking in activated sludge. FeO could increase the coenzyme Q activity in IET and the content of free riboflavin and cytochrome c in EET. Metagenomic analysis indicated that denitrification, sulfide oxidation and sulfate reduction were the main pathways of nitrogen and sulfur metabolism, and the enriched denitrifying bacteria (Halomonas and Hypobacterium) and sulfur-oxidizing bacteria (Marinicella) could stably support nitrate removal. This study expands our understanding of the IET/EET during FeO-mediated mixotrophic denitrification process, providing a novel insight for nitrogen removal from marine recirculating aquaculture wastewater.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.envres.2024.120237 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Mixotrophic denitrification using thiocyanate as an electron donor: Role of thiocyanate under different C/N conditions.
J Environ Manage
January 2025
School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, PR China. Electronic address:
Thiocyanate (SCN) is a highly toxic reducing inorganic compound commonly found in various nitrogen-rich wastewater and is also a promising electron donor for mixotrophic denitrification. However, its extent of involvement in mixotrophic denitrification under conditions of carbon limitation or excess remains unclear. In this study, five reactors were constructed to investigate the participation and microbial mechanisms of SCN in mixotrophic denitrification under high C/N and low C/N conditions.
View Article and Find Full Text PDFInsight into enhanced adaptability of iron-carbon biofilter in treating low-carbon nitrogen mariculture wastewater for nitrogen removal and carbon reduction.
Bioresour Technol
January 2025
Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044 China. Electronic address:
Iron-carbon (Fe-C) based biofilters have shown significant advantages in treating mariculture wastewater by facilitating the mixotrophic heterotrophic nitrification-aerobic denitrification (HNAD) process. However, the effects of Fe-C materials and varying carbon-to-nitrogen (C/N) ratios on N removal and C reduction performance remain insufficiently explored. This study demonstrated that the Fe-C biofilter (R-Fe) achieved significantly higher NO-N removal efficiency (65.
View Article and Find Full Text PDFFoam FeSO modified limestone sulfur concrete for non-stink and high-rate nitrogen and phosphorus removal from wastewater.
Water Res
March 2025
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163# Xianlin Ave., Nanjing 210023, China. Electronic address:
Aiming at disadvantages of conventional sulfur-limestone autotrophic denitrification system, such as producing stink (HS) and low-rate nitrogen and phosphorus removal from wastewater with low C/N, foam FeSO modified limestone sulfur concrete (FFLSC) was prepared. Experimental parameters of FFLSC biofilter, such as hydraulic retention time (HRT), influent NO-N, additional alkalinity and COD addition, were tested. For wastewater without COD, FFLSC biofilter could simultaneously remove TON (NO-N+NO-N) from 22.
View Article and Find Full Text PDFMicrobial biomass stoichiometry and proportion of Fe organic complexes separately shape the heterogeneity of mixotrophic denitrification and net NO sinks in iron-carbon amended ecological ditch.
Water Res
December 2024
School of Environment, Nanjing Normal University, Jiangsu Province Engineering Research Center of Environmental Risk Prevention and Emergency Response Technology, Jiangsu Engineering Lab of Water and Soil Eco-remediation, Wenyuan Road 1, Nanjing 210023, PR China. Electronic address:
Coupling of iron-carbon can form a mixotrophic denitrification and is regarded as a promising solution for purifying nitrate-rich agricultural runoff. However, its prevalence and efficacy of the synergistic augmentation of nitrogen elimination and net NO sinks remain crucial knowledge gaps in ecological ditches (eco-ditches). Here, we investigated the underlying variability mechanisms by implementing sponge iron (sFe)-coupled Iris hexagonus (IH)- or Myriophyllum aquaticum (MA)-derived biochar produced via microwave-assisted (MW) pyrolysis and conventional pyrolysis.
View Article and Find Full Text PDFDual-layer elemental sulfur-packed denitrification reactor to control sulfate generation and sulfide discharge by two-point inlet and internal recirculation.
Bioresour Technol
February 2025
College of Environmental Engineering, Henan University of Technology, Zhengzhou 450001, China. Electronic address:
Article Synopsis
- The study developed two types of reactors, the SADR and WSMDR, for removing nitrate from water, achieving denitrification rates of 66-114 g-N/(m·d) and 70-104 g-N/(m·d), respectively.
- Sulfate production in both reactors was lower than theoretical predictions, with the SADR producing 5.5-5.9 mg SO/mg reduced N and the WSMDR producing 3.2-4.5 mg SO/mg reduced N, while no sulfide was emitted.
- Key microorganisms like Chlorobium and Thiobacillus were identified as crucial for nitrate reduction, and improved denitrification performance was linked to a higher abundance of functional genes
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!