After a period of ultrafiltration process to treat oil waste water,
the membrane fouling was so severe that the membranes needed
to be cleaned with detergent. In this study, the DI water and
3 wt.% NaOH aqueous solution were conducted as detergent to
clean the membranes for 10 min, respectively. Then the stable permeation
flux through the cleaned membranes is denoted as Jt and
calculated by Eq. (4). In order to evaluate the antifouling ability of
membranes, flux recovery is introduced as FR and calculated by Eq.
(5):