Function of self-forming dynamic membrane and biokinetic parameters' determination by microelectrode

Area of Science:

• Environmental Biotechnology
• Biochemical Engineering
• Membrane Science

Background:

• Self-forming dynamic membrane bioreactors (SFDMBRs) offer advantages over traditional membrane bioreactors (MBRs) due to lower costs and higher flux.
• Understanding microbial activity within the dynamic membrane (DM) is crucial for optimizing SFDMBR performance.
• Bio-fouling significantly impacts the operational efficiency and microbial dynamics within SFDMs.

Purpose of the Study:

• To investigate the changes in microbial activity within a self-forming dynamic membrane (DM) during the bio-fouling process.
• To develop a model for estimating biokinetic parameters based on dissolved oxygen profiles.
• To analyze the impact of bio-fouling on microbial activity and oxygen uptake rates.

Main Methods:

• Utilized a microelectrode to measure dissolved oxygen (DO) profiles within the self-forming DM at a flux of 40 L/m2h.
• Developed a computational model to estimate biokinetic parameters from DO concentration profiles.
• Performed sensitivity analysis to identify key parameters influencing DO profiles.

Main Results:

• Dissolved oxygen was depleted at depths of 1.5-2.0 mm within the self-forming DM.
• The model successfully estimated biokinetic parameters, with maximum specific oxygen uptake rates (qO2max) ranging from 3.8-11.1 mg O2/gSS h.
• qO2max decreased sharply in the initial 5 days of bio-fouling before reaching a steady state; the Monod half-saturation coefficient for oxygen (KO) ranged from 0.16-0.75 mgO2/L.

Conclusions:

• The study provides experimental evidence of microbial activity changes in self-forming DMs during bio-fouling.
• The developed model offers a reliable method for estimating biokinetic parameters in SFDMBRs.
• Understanding these dynamics is essential for the design and operation of efficient SFDMBRs.