Intermittent aeration to regulate microbial activities in membrane-aerated biofilm reactors: Energy-efficient nitrogen removal and low nitrous oxide emission

Ma，Yunjie1,2; Piscedda，Andrea1; Veras，Antia De La C.1; Domingo-Félez，Carlos1; Smets，Barth F.1

2021

10.1016/j.cej.2021.133630

CHEMICAL ENGINEERING JOURNAL   影响因子和分区

1385-8947

Membrane-aerated biofilm reactors (MABR) are being applied for autotrophic nitrogen removal, yet control of nitrogen turnover remains challenging in MABR counter-diffusion biofilms. In this study, we regulated microbial activities in two lab-scale MABRs by providing continuous versus intermittent aeration. Nitrogen consumption by different functional microbial groups was estimated from bulk measurements via a mass balance approach. Nitrite-oxidizing bacteria (NOB) proliferated under continuous aeration while they were significantly suppressed under intermittent aeration, and NOB suppression activated anaerobic ammonium oxidation. Nitritation performance in the MABR was studied through long-term bulk measurements and in situ biofilm microprofiles of dissolved oxygen (DO) and pH. During intermittent aeration pH effects rather than DO effects determined nitritation success, especially ammonia speciation, which serves as substrate and inhibitor in nitrification processes. Biofilm transition phases were monitored upon aeration switches. Canonical correspondence analysis suggested that the relative transition after anoxia and aeration intermittency were less decisive for biofilm performance than the relative aeration duration. Heterotrophic bacteria displayed minor denitrification rates with aeration control, but contributed to mitigation of nitrous oxide (NO) emissions. NO production hotspots were identified at the top of the anoxic biofilm zone under continuous aeration. Instead, under intermittent aeration an anoxic NO reduction zone was established. Our observations support intermittent aeration control of MABRs as a simple strategy for energy-efficient nitrogen removal with low NO emission.

Aeration control Microprofile N2O emission Nitrogen cycle NOB suppression Transition phase

EI

英语

其他

20214911282566

Ammonia ; Biofilms ; Bioreactors ; Denitrification ; Dissolved oxygen ; Energy efficiency ; Nitrification ; Nitrogen oxides ; Nitrogen removal ; pH effects

Biotechnology:461.8 ; Biomaterials (including synthetics):462.5 ; Energy Conservation:525.2 ; Chemistry, General:801.1 ; Chemical Plants and Equipment:802.1 ; Chemical Reactions:802.2 ; Inorganic Compounds:804.2

ENGINEERING

2-s2.0-85120447374

Scopus

1.Department of Environmental Engineering,Technical University of Denmark,Kongens Lyngby,2800,Denmark
2.School of Environmental Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China

Ma，Yunjie,Piscedda，Andrea,Veras，Antia De La C.,et al. Intermittent aeration to regulate microbial activities in membrane-aerated biofilm reactors: Energy-efficient nitrogen removal and low nitrous oxide emission[J]. CHEMICAL ENGINEERING JOURNAL,2021,433.

Ma，Yunjie,Piscedda，Andrea,Veras，Antia De La C.,Domingo-Félez，Carlos,&Smets，Barth F..(2021).Intermittent aeration to regulate microbial activities in membrane-aerated biofilm reactors: Energy-efficient nitrogen removal and low nitrous oxide emission.CHEMICAL ENGINEERING JOURNAL,433.

Ma，Yunjie,et al."Intermittent aeration to regulate microbial activities in membrane-aerated biofilm reactors: Energy-efficient nitrogen removal and low nitrous oxide emission".CHEMICAL ENGINEERING JOURNAL 433(2021).