Study on the Synchronous Removal of Nitrogen and Phosphorus by Autotrophic/Heterotrophic Denitrification in the Presence of Pyrite

Pollution caused by N and P is a significant contributor to water eutrophication. While traditional biological treatment processes can remove some N and P elements from water, the effluent quality often fails to meet the stringent requirements of sensitive areas. The autotrophic denitrification’s si...

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Main Authors: Minyi Zhu, Minhui Ma, Shuo Chen, Rongfang Yuan, Shaona Wang
Format: Article
Language:English
Published: MDPI AG 2025-05-01
Series:Molecules
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Online Access:https://www.mdpi.com/1420-3049/30/11/2412
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author Minyi Zhu
Minhui Ma
Shuo Chen
Rongfang Yuan
Shaona Wang
author_facet Minyi Zhu
Minhui Ma
Shuo Chen
Rongfang Yuan
Shaona Wang
author_sort Minyi Zhu
collection DOAJ
description Pollution caused by N and P is a significant contributor to water eutrophication. While traditional biological treatment processes can remove some N and P elements from water, the effluent quality often fails to meet the stringent requirements of sensitive areas. The autotrophic denitrification’s simultaneous nitrogen and phosphorus removal pro-cess, known for its low operating cost and minimal sludge production, has garnered considerable attention from researchers. In this study, natural pyrite was used for the removal of nitrogen and phosphorus in a denitrification system, and the underlying mechanisms were elucidated. The results indicate that the N and P removal efficiency was influenced by empty bed contact time (EBCT) and the pH value. The highest NO<sub>3</sub><sup>−</sup>-N removal rate of 90.24% was achieved at an EBCT of 8 h, while the PO<sub>4</sub><sup>3−</sup>-P removal rate reached 81.58% at an EBCT of 12 h. The addition of a carbon source enhanced the synergistic autotrophic/heterotrophic denitrification, significantly improving phosphorus removal with an increasing C/N ratio. Microbial characteristics analysis revealed that, at the phylum level, <i>Chlorobiota</i>, <i>Bacteroidota</i>, and <i>Chloroflexota</i> played a crucial role in heterotrophic autotrophic denitrification. At the genus level, <i>Thauera</i>, <i>Aridibacter</i>, and <i>Gemmatimonas</i> were key players in heterotrophic denitrification, while <i>Thiobacillus</i>, <i>Rhodoplanes</i>, and <i>Geobacter</i> were associated with autotrophic denitrification.
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spelling doaj-art-5adef71c82d04848b7509eef5cc320f42025-08-20T02:23:08ZengMDPI AGMolecules1420-30492025-05-013011241210.3390/molecules30112412Study on the Synchronous Removal of Nitrogen and Phosphorus by Autotrophic/Heterotrophic Denitrification in the Presence of PyriteMinyi Zhu0Minhui Ma1Shuo Chen2Rongfang Yuan3Shaona Wang4Department of Environmental Science and Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaDepartment of Environmental Science and Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaDepartment of Environmental Science and Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaDepartment of Environmental Science and Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaDepartment of Environmental Science and Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaPollution caused by N and P is a significant contributor to water eutrophication. While traditional biological treatment processes can remove some N and P elements from water, the effluent quality often fails to meet the stringent requirements of sensitive areas. The autotrophic denitrification’s simultaneous nitrogen and phosphorus removal pro-cess, known for its low operating cost and minimal sludge production, has garnered considerable attention from researchers. In this study, natural pyrite was used for the removal of nitrogen and phosphorus in a denitrification system, and the underlying mechanisms were elucidated. The results indicate that the N and P removal efficiency was influenced by empty bed contact time (EBCT) and the pH value. The highest NO<sub>3</sub><sup>−</sup>-N removal rate of 90.24% was achieved at an EBCT of 8 h, while the PO<sub>4</sub><sup>3−</sup>-P removal rate reached 81.58% at an EBCT of 12 h. The addition of a carbon source enhanced the synergistic autotrophic/heterotrophic denitrification, significantly improving phosphorus removal with an increasing C/N ratio. Microbial characteristics analysis revealed that, at the phylum level, <i>Chlorobiota</i>, <i>Bacteroidota</i>, and <i>Chloroflexota</i> played a crucial role in heterotrophic autotrophic denitrification. At the genus level, <i>Thauera</i>, <i>Aridibacter</i>, and <i>Gemmatimonas</i> were key players in heterotrophic denitrification, while <i>Thiobacillus</i>, <i>Rhodoplanes</i>, and <i>Geobacter</i> were associated with autotrophic denitrification.https://www.mdpi.com/1420-3049/30/11/2412autotrophic denitrificationnitrogen and phosphorus removalpyritebiofiltermicrobial characteristics
spellingShingle Minyi Zhu
Minhui Ma
Shuo Chen
Rongfang Yuan
Shaona Wang
Study on the Synchronous Removal of Nitrogen and Phosphorus by Autotrophic/Heterotrophic Denitrification in the Presence of Pyrite
Molecules
autotrophic denitrification
nitrogen and phosphorus removal
pyrite
biofilter
microbial characteristics
title Study on the Synchronous Removal of Nitrogen and Phosphorus by Autotrophic/Heterotrophic Denitrification in the Presence of Pyrite
title_full Study on the Synchronous Removal of Nitrogen and Phosphorus by Autotrophic/Heterotrophic Denitrification in the Presence of Pyrite
title_fullStr Study on the Synchronous Removal of Nitrogen and Phosphorus by Autotrophic/Heterotrophic Denitrification in the Presence of Pyrite
title_full_unstemmed Study on the Synchronous Removal of Nitrogen and Phosphorus by Autotrophic/Heterotrophic Denitrification in the Presence of Pyrite
title_short Study on the Synchronous Removal of Nitrogen and Phosphorus by Autotrophic/Heterotrophic Denitrification in the Presence of Pyrite
title_sort study on the synchronous removal of nitrogen and phosphorus by autotrophic heterotrophic denitrification in the presence of pyrite
topic autotrophic denitrification
nitrogen and phosphorus removal
pyrite
biofilter
microbial characteristics
url https://www.mdpi.com/1420-3049/30/11/2412
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