Surface modification of PVDF hollow fiber membrane and its application in membrane aerated biofilm reactor (MABR)

•DOPA composite membrane for MABR was prepared by surface modification.•Gas permeation & surface properties of the membrane were improved by modification.•The modified membrane has a good performance in MABR. A novel composite hollow fiber membrane for membrane aerated biofilm rector (MABR) was prepared by coating L-3,4-dihydroxyphenylalanine (DOPA) on the surface of PVDF membrane. MABR process study was conducted to test the performances of the original and modified membranes for 166days. The results indicate that coated membrane showed 2times higher gas flux, lower water contact angle (declined from 86.5° to 52°), and significantly improved surface roughness. The modified membrane displayed an excellent MABR performance. Its COD, NH4+–N and TN removal efficiencies were kept above 90%, 98.8% and 84.2% during the first 4-month experiment. By tracking experiment at 0.01MPa, to achieve COD removal efficiency of 85.9%, half an hour is required with the modified membrane, instead of 6h using the original one. Besides, faster NH4+–N and TN removal at 0.01MPa were also achieved with DOPA composite membrane.