Heterotrophic denitrification enhancement via effective organic matter degradation driven by suitable iron dosage in sediment

Pan Yan; Tang Li; Tongtong Ren; Yue Zang; Shanshan Sun; Yuanyuan Fan; Yu Zhang; Xushun Gu; Shengbing He

doi:10.1016/j.jenvman.2025.124275

Heterotrophic denitrification enhancement via effective organic matter degradation driven by suitable iron dosage in sediment

J Environ Manage. 2025 Jan 24:375:124275. doi: 10.1016/j.jenvman.2025.124275. Online ahead of print.

Authors

Pan Yan¹, Tang Li¹, Tongtong Ren¹, Yue Zang¹, Shanshan Sun¹, Yuanyuan Fan¹, Yu Zhang¹, Xushun Gu², Shengbing He³

Affiliations

¹ School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, PR China.
² School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, PR China; School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, PR China.
³ School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, PR China. Electronic address: heshengbing@sjtu.edu.cn.

PMID: 39862819
DOI: 10.1016/j.jenvman.2025.124275

Abstract

The control of internal pollution was important throughout the restoration of the lake, especially the removal of sediment internal nitrogen. Experiments involving incubation were conducted in this study to investigate the effects of iron remediation on nitrogen in both water and sediment. Adding iron with varying dosage had different effects on the nutrients content and other properties of water and sediment in remediation. The higher the addition dosage of iron, the more iron ions were released into the interstitial and overlying water. The effect of 5% and 10% iron dosage on the interstitial and overlying water were more obvious, which can significantly increase the pH and decrease the ORP of the sediment, and significantly increase the TN and NH₄⁺-N contents in overlying water. Nevertheless, higher iron addition dosage decreased relative abundance of the genera related to denitrification (Thiobacillus) and DNRA (Bacillus). The relative abundance of Anaerolineae was increased with the iron addition dosage, promoted the reduction of organic matter and iron cycle in sediment. The iron addition dosage of 2% had less effect on the overlying water quality, and promoted the nitrogen removal process by changing the abundance of microorganisms related to the sediment nitrogen cycle. This study provides essential information for internal pollution control of lakes and serves as a valuable reference for developing eutrophication management framework.

Keywords: Iron dosage; Microbial community; Nitrogen removal; Sediment remediation.