TY - JOUR
T1 - Microalgae-bacteria symbiosis enhanced nitrogen removal from wastewater in an inversed fluidized bed bioreactor
T2 - performance and microflora
AU - Zheng, Xin
AU - Liu, Ruoting
AU - Li, Kai
AU - Sun, Junhao
AU - Wang, Kanming
AU - Shao, Yuanyuan
AU - Hu, Zhongce
AU - Zhu, Jesse
AU - Pan, Zhiyan
AU - Nakhla, George
N1 - Publisher Copyright:
Copyright © 2025 Zheng, Liu, Li, Sun, Wang, Shao, Hu, Zhu, Pan and Nakhla.
PY - 2025
Y1 - 2025
N2 - Conventional wastewater biological nitrogen removal (BNR) processes require a large amount of air and external organic carbon, causing a significant increase in operating costs and potential secondary pollution. Herein, this study investigated the nitrogen removal performance and the underlying mechanisms of a novel simultaneous nitrification and denitrification (SND) coupled with photoautotrophic assimilation system in an inversed fluidized bed bioreactor (IFBBR). Nitrogen removal was achieved through the synergistic interaction of microalgae and bacteria, with microalgae providing O2 for nitrification and microbial biomass decay supplying organic carbon for denitrification. The IFBBR was continuously operated for more than 240 days without aeration and external organic carbon, the total nitrogen (TN) removal efficiency reached over 95%. A novel C-N-O dynamic balance model was constructed, revealing that nitrification and denitrification were the primary pathways for nitrogen removal. The model further quantified the microbial contributions, showing that microalgae generated O2 at a rate of 81.82 mg/L·d, while microbial biomass decay released organic carbon at a rate of 148.66 mg/L·d. Microbial diversity analysis confirmed the majority presence of microalgae (Trebouxiophyceae), nitrifying bacteria (Gordonia and Nitrosomonas) and denitrifying bacteria (Ignavibacterium and Limnobacter). This study successfully achieved enhanced nitrogen removal without the need for aeration or external organic carbon. These advancements provide valuable insights into efficient wastewater nitrogen removal, offering significant benefits in terms of reduced energy consumption, lower operational costs, and decreased CO2 emissions.
AB - Conventional wastewater biological nitrogen removal (BNR) processes require a large amount of air and external organic carbon, causing a significant increase in operating costs and potential secondary pollution. Herein, this study investigated the nitrogen removal performance and the underlying mechanisms of a novel simultaneous nitrification and denitrification (SND) coupled with photoautotrophic assimilation system in an inversed fluidized bed bioreactor (IFBBR). Nitrogen removal was achieved through the synergistic interaction of microalgae and bacteria, with microalgae providing O2 for nitrification and microbial biomass decay supplying organic carbon for denitrification. The IFBBR was continuously operated for more than 240 days without aeration and external organic carbon, the total nitrogen (TN) removal efficiency reached over 95%. A novel C-N-O dynamic balance model was constructed, revealing that nitrification and denitrification were the primary pathways for nitrogen removal. The model further quantified the microbial contributions, showing that microalgae generated O2 at a rate of 81.82 mg/L·d, while microbial biomass decay released organic carbon at a rate of 148.66 mg/L·d. Microbial diversity analysis confirmed the majority presence of microalgae (Trebouxiophyceae), nitrifying bacteria (Gordonia and Nitrosomonas) and denitrifying bacteria (Ignavibacterium and Limnobacter). This study successfully achieved enhanced nitrogen removal without the need for aeration or external organic carbon. These advancements provide valuable insights into efficient wastewater nitrogen removal, offering significant benefits in terms of reduced energy consumption, lower operational costs, and decreased CO2 emissions.
KW - biological nitrogen removal
KW - mass balance
KW - microalgal-bacterial symbiosis system
KW - simultaneous nitrification and denitrification
KW - syntrophic microbial communities
UR - http://www.scopus.com/inward/record.url?scp=105004775603&partnerID=8YFLogxK
U2 - 10.3389/fmicb.2025.1591974
DO - 10.3389/fmicb.2025.1591974
M3 - Article
AN - SCOPUS:105004775603
SN - 1664-302X
VL - 16
JO - Frontiers in Microbiology
JF - Frontiers in Microbiology
M1 - 1591974
ER -