Analysis of UF membrane fouling mechanisms caused by organic interactions in seawater

► High salt concentration promoted fouling potential of humic acid and alginate. ► Alginate fouling layer became more irreversible under high salt concentration. ► Higher fouling removal by cyclic backwash with deionized water than permeate water. ► Deionized water backwash promoted alginate foulant removal but not humic acid. ► Trace of irrecoverable fouling by humic acid accumulated for cyclic deionized water backwash.