The fouled FO membranes were taken our from the OMBRs
on days 3, 8 and 25 in sequence, and then the FO membrane
samples were obtained by cutting from the middle of the
fouled membranes. The fouled membrane samples were
analyzed by a Fourier transform infrared (FT-IR) spectrophotometer
(Nicolet iS10, Thermo Fisher Scientific, America) to
characterize the major functional groups of the organic foulants
on the FO membrane surface after pretreating in a vacuum
freeze drying machine for 24 h.