Integration of Specific Aeration Demand (SAD) into Flux-Step Test for Submerged Membrane Bioreactor

Area of Science:

• Environmental Science
• Chemical Engineering
• Materials Science

Background:

• Membrane fouling significantly impacts the efficiency and energy consumption of membrane bioreactors (MBRs).
• Existing methods like flux-step tests (FSTs) may not fully capture operational complexities related to aeration.

Purpose of the Study:

• To develop and validate a novel methodology integrating aeration-step tests (ASTs) with FSTs for assessing fouling in ultrafiltration hollow-fibre (UF-HF) membranes.
• To optimize the specific aeration demand (SADm) for different membrane types and aeration modes in MBRs.

Main Methods:

• Implemented ASTs alongside FSTs to evaluate UF-HF membranes manufactured via non-thermal-induced phase separation (NIPS) and thermal-induced phase separation (TIPS).
• Tested membranes under both continuous and intermittent aeration conditions.
• Determined critical SADm ranges for optimal fouling management.

Main Results:

• Identified critical SADm ranges: 0.1-0.5 m³·m⁻²·h⁻¹ for continuous aeration and 0.1-0.2 m³·m⁻²·h⁻¹ for intermittent aeration.
• NIPS membranes showed less fouling under intermittent aeration, while TIPS membranes recovered better with continuous aeration, indicating distinct fouling behaviors.
• Aeration efficiency is demonstrably linked to membrane structure and aeration mode.

Conclusions:

• Combining FSTs with ASTs provides a more comprehensive approach to fouling assessment in MBRs.
• This integrated methodology enables the development of tailored fouling control strategies, leading to reduced energy consumption.
• The findings are crucial for advancing energy-efficient wastewater treatment technologies through optimized membrane operation.