Revealing sulfur-iron coupling mechanism for enhanced autotrophic denitrification in ecological floating beds

Feng Xu; Yuanyuan Peng; Xushun Gu; Shanshan Sun; Anqi Li; Shengbing He

doi:10.1016/j.biortech.2024.130800

Revealing sulfur-iron coupling mechanism for enhanced autotrophic denitrification in ecological floating beds

Bioresour Technol. 2024 May 9:402:130800. doi: 10.1016/j.biortech.2024.130800. Online ahead of print.

Authors

Feng Xu¹, Yuanyuan Peng¹, Xushun Gu¹, Shanshan Sun², Anqi Li¹, 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. Electronic address: sunss2017@sjtu.edu.cn.
³ School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China; Shanghai Engineering Research Center of Landscape Water Environment, Shanghai 200031, PR China. Electronic address: heshengbing@sjtu.edu.cn.

PMID: 38734259
DOI: 10.1016/j.biortech.2024.130800

Abstract

A sulfur-iron coupled ecological floating bed (EFB-SFe) was developed to enhance the denitrification capability of sulfur-based ecological floating beds (EFB-S). The denitrification performance, kinetic process and microbial community composition were explored. Results showed that sulfur-iron coupling effectively enhanced the denitrification performance of EFB, surpassing the sum of their individual effects. The average total nitrogen removal rate ranged from 1.56 to 4.56 g·m^-2·d^-1, with a removal efficiency of 22-84 %. The k value for the S + Fe group increased from 0.04 to 0.18 d^-1 to 0.40-0.46 d^-1 relative to the S group. The sulfur-iron coupling promoted the enrichment of denitrifying bacteria (Thiobacillus and Ferritrophicum). The denitrification genes in EFB-SFe were upregulated, being 12-22 times more abundant than in EFB-S. Sulfur and iron autotrophic denitrification were identified as the main nitrogen removal processes in EFB-SFe. Overall, sulfur-iron coupling showed the potential to enhance the denitrification capacity of EFB-S for treating low-pollution water.

Keywords: Autotrophic electron donor; Kinetic process; Low-pollution water; Synergistic nitrogen removal.