DOPA/PEI surface-modified poly-4-methyl-1-pentene membranes and application in membrane aeration biofilm reactor

The membrane aeration biofilm reactor (MABR) represents an innovative approach to wastewater treatment, integrating gas separation membranes with biofilm process and demonstrating effectiveness in treating wastewater rich in ammonia nitrogen. In this system, hollow fiber membranes are essential, serving as a substrate for biofilm attachment while facilitating oxygen transfer to microorganisms through aeration, hydrophobic microporous membranes are utilized in MABR applications. This study focuses on the use of poly-4-methyl-1-pentene (PMP) hollow fiber membranes, which exhibit superior oxygen permeation capabilities compared to traditional hydrophobic microporous membranes. To overcome the challenges posed by the hydrophobic nature and low bubble point of PMP microporous membranes, a hydrophilic modification was conducted using dopamine/poly(ethyleneimine) (DOPA/PEI) co-deposition to enhance microbial adhesion on the membrane surface. The composite membrane modified with DOPA/PEI exhibited an approximately 20% higher NH 4 + -N removal efficiency than the unmodified membrane. These findings suggest that the incorporation of DOPA/PEI significantly improves MABR performance, underscoring its potential for further research and development in membrane technology for MABR.