Conventional　treatment　such　as　coagulation　and　sand　filtration　prior　to　ultrafiltration　(UF)　is　widely　used　for　treating　contaminated　surface　water　sources　for　potable　supply.　While　beneficial,　conventional　treatment　alone　is　unable　to　control　membrane　fouling　effectively　in　many　cases,　and　there　is　continuing　interesting　in　the　use　of　additional,　complementary　methods　such　as　oxidation　and　adsorption　in　the　pre-treatment　of　raw　water　prior　to　UF.　In　this　study,　the　applications　of　ozonation　(O-3)　and　powdered　activated　carbon　(PAC)　in　the　submerged　UF　system　(SUF)　have　been　evaluated　at　laboratory-scale　employing　test　water　after　conventional　water　treatment.　In　parallel　tests　with　and　without　the　pretreatment,　the　impact　of　O-3　on　the　increase　of　trans-membrane　pressure　was　evaluated　and　with　the　analysis　of　membrane　fouling　resistance,　both　as　the　cake　layer　and　within　membrane　pores.　The　results　indicated　that　the　O-3/SUF　system　can　alleviate　about　20.43%　membrane　fouling,　compared　with　SUF　system　without　pre-ozonation.　Pre-ozonation　combined　with　PAC　removed　protein-like　substances,　resulted　in　a　39.2%　reduction　of　total　organic　carbon;　increased　the　amount　of　attached　biomass　on　the　PAC　and　membrane　surface,　resulted　in　the　improvement　of　the　biodegradability　of　microorganisms.　The　application　of　O-3　can　reduce　the　stickiness　of　surface　of　organic　pollutants,　which　is　beneficial　to　remove　the　pollutants　deposited　on　membrane　surface　by　chemical　backwashing.　Therefore,　the　application　of　pre-ozonation　and　PAC　within　SUF　system　is　a　potentially　important　approach　for　fully　mitigating　membrane　fouling.　(C)　2020　Elsevier　B.V.　All　rights　reserved.