The membranes were conditioned with pure water and the flux (F0) was measured for 10 min. After filtering 150 mL of the simulated produced water, pure water was fed to the system to wash the membranes for 10 min and the flux was measured within this period and denoted by Fi. The fouling-cleaning cycle was repeated three times to measure the FRR. SEM-EDX analysis was performed on the membrane top surface to examine the fouled layer after the filtration of 0.5 L produced water, followed by rinsing with pure water.