Performance and microbial ecology of biofilms adhering on aerated membrane with distinctive conditions for the treatment of domestic sewage

ABSTRACT

When used to treat domestic wastewater, biofilms adhering to oxygen-permeable membranes are generally altered by environmental conditions. In this study, the effect of common conditions, including salinity, temperature, air-supplying pressure, flow velocity, influent COD, and NH₄-N on the biofilm structure were determined. Principal component analysis revealed that archaeal community was more easily affected by the changing conditions than bacteria. The subsequent redundancy analysis showed that salinity had the most influence on bacteria, followed by temperature, influent COD, flow velocity, pressure, and influent NH₄-N. In archaea, temperature had the highest effect, followed by flow velocity, salinity, influent NH₄-N, pressure, and influent COD. The key bacterial class Anaerolineae was not easily influenced by the above conditions, but the population probably contributed to the nitrogen removal. Gammaproteobacteria was promoted significantly by influent NH₄-N concentration, salinity, and pressure. Betaproteobacteria and Deltaproteobacteria were apparently inhibited by the high salinity and contributed to the organic compound degradation. Flow velocity primarily promoted the growth of Alphaproteobacteria. Candidatus Nitrososphaera had a higher tolerance for salinity but lower tolerance for influent NH₄-N than Nitrosomonas. The former probably played a more crucial role in ammoxidation. Methanomethylovorans might disrupt nitrogen removal because it could consume the carbon source for denitrification.

GRAPHICAL ABSTRACT

KEYWORDS:

• Membrane-aerated biofilm reactor
• microbial structure
• biofilm
• environmental conditions
• correlation

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by the National Natural Science Foundation of China (No.31700105), Key Laboratory Funds of Transformation and Utilization of Grain Resources in Henan Province (No. PL2016006), and the Fundamental Research Funds for the Henan Provincial University (No. 2017QNJH12), the Key Scientific Research Project of Universities in Henan Province (No. 17B610005), the Doctoral Scientific Research Start-up Foundation from Henan University of Technology (No. 2016BS004), and National Natural Science Foundation of China (No. 31401543, U1304332).