Ultrafiltration(UF)has　been　increasingly　implemented　in　drinking　water　treatment　plants;however,algae　and　their　secretions　can　cause　severe　membrane　fouling　and　pose　great　challenges　to　UF　in　practice.In　this　study,a　simple　and　practical　chemically　enhanced　backwashing(CEB)process　was　developed　to　address　such　issues　using　various　cleaning　reagents,including　sodium　hypochlorite(NaClO),sodium　chloride(NaCl),sodium　hydroxide(NaOH),sodium　citrate,and　their　combinations.The　results　indicate　that　the　type　of　chemical　played　a　fundamental　role　in　alleviating　the　hydraulically　irreversible　mem-brane　fouling(HIMF),with　NaClO　as　the　best-performing　reagent,followed　by　NaCl.Furthermore,a　CEB　process　using　a　combination　of　NaClO　with　NaCl,NaOH,or　sodium　citrate　delivered　little　improve-ment　in　the　alleviation　of　membrane　fouling　compared　with　NaClO　alone.The　optimized　dosage　and　dos-ing　frequency　of　NaClO　were　10　mg·L-1　two　times　per　day.Long-term　pilot-scale　and　full-scale　experiments　further　verified　the　feasibility　of　the　CEB　process　in　relieving　algae-derived　membrane　foul-ing.Compared　with　the　conventional　hydraulic　backwashing　without　chemical　involvement,the　CEB　pro-cess　can　effectively　remove　the　organic　foulants　including　biopolymers,humic　substances,and　protein-like　substances　by　means　of　oxidization,thereby　weakening　the　cohesive　forces　between　the　organic　fou-lants　and　the　membrane　surface.Therefore,the　CEB　process　can　efficiently　alleviate　the　algae-related　membrane　fouling　with　lower　chemical　consumption,and　is　proposed　as　an　alternative　to　control　mem-brane　fouling　in　treating　the　algae-containing　surface　water.