Deciphering nitrogen removal performance concerning heterotrophic microorganism's succession by using three typical acid-rich fermentation liquids of food waste as carbon sources in high ammonium and high salt wastewater treatment

Mingjiang Zhang; Chencan Zhang; Qiusheng Wu; Murong Wang; Yujun Zhou; Dianzhan Wang; Lixiang Zhou

doi:10.1016/j.envres.2025.120763

Deciphering nitrogen removal performance concerning heterotrophic microorganism's succession by using three typical acid-rich fermentation liquids of food waste as carbon sources in high ammonium and high salt wastewater treatment

Environ Res. 2025 Jan 4:268:120763. doi: 10.1016/j.envres.2025.120763. Online ahead of print.

Authors

Mingjiang Zhang¹, Chencan Zhang¹, Qiusheng Wu², Murong Wang¹, Yujun Zhou³, Dianzhan Wang¹, Lixiang Zhou⁴

Affiliations

¹ Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
² State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China.
³ School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210095, China.
⁴ Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing, 210095, China. Electronic address: lxzhou@njau.edu.cn.

PMID: 39761780
DOI: 10.1016/j.envres.2025.120763

Abstract

Understanding the performance and microbial succession in nitrogen removal using fermentation liquid as carbon source can provide a practical basis for treating low C/N ratio wastewater. In this study, three typical fermentation liquids of food waste (FW) enriched with lactic acid (LA), propionic acid (PA), and butyric acid (BA) were added to high ammonia and high salt (HAHS) wastewater treatment process. Results showed that effluent TN decreased from 50 mg/L to around 15 mg/L with the influent concentration around 1000 mg/L after adding fermentation liquid enriched with LA and PA. In contrast, adding BA-rich fermentation liquid gradually deteriorated the nitrogen removal due to the nitrification process being impaired. Genus Thauera predominated in HAHS wastewater system via heterotrophic simultaneous nitrification and denitrification (SND) process. Utilization of LA- and PA-rich fermentation liquids induced the acclimation of other heterotrophic SND microbes and partially replaced Thauera. Conversely, BA-rich carbon source promoted the proliferation of heterotrophic denitrifying and ordinary heterotrophic microorganisms, thereby inhibiting nitrification process and ultimately leading to the failure of nitrogen removal. Meanwhile, the relative abundance of denitrification genes, including napAB, nirKS, norBC, and NosZ, annotated in Thauera exhibited the lowest relative abundance in BA-rich phase. This study provides valuable insights into the mechanism of using FW fermentation liquid as an alternative carbon source to promote nitrogen removal in HAHS wastewater.

Keywords: Anaerobic digestate; Carbon source; Fermentation liquid; Heterotrophic nitrification; High ammonia and high salt; Nitrogen removal.