Various　pretreatments　of　raw　surface　water　before　ultrafiltration　(UF)　to　retard　membrane　fouling　due　to　natural　organic　matter　(NOM)　were　compared　in　this　study.　Water　treatment　by　conventional　coagulation,　visible　light　irradiation　with　the　presence　of　a　novel　photocatalyst　of　Bi2O3-TiO2　supported　onto　powder　activated　carbon　(BieTi/PAC),　and　their　combination　were　compared　in　terms　of　removal　of　NOM　and　the　optimal　conditions　were　determined.　The　composite　nano-photocatalyst　of　Bi-Ti/PAC　could　function　as　a　pre-oxidant　and　a　flocculation　core　assisting　coagulation.　Experiments　results　show　that　58%　of　the　NOM　present　could　be　removed　by　quantization　of　dissolved　organic　carbon　in　the　combination　treatment　under　optimal　conditions　of　2.0　g/L　of　photocatalyst　dosage　with　light　exposure　of　20　min　and　0.04　mmol　polyaluminium　chloride　coagulant　dosage　with　a　solution　pH　of　7.　The　combined　pretreatment　with　UF　produced　a　reduction　of　88%　in　total　membrane　fouling,　with　reversible　and　irreversible　fouling　being　significantly　decreased　because　of　the　removal　of　hydrophilic,　protein-　and　humic-like　substances,　along　with　degradation　and　removing　of　medium-molecular　weight　(MW)　and　high-MW　compounds　into　smaller　molecules.　Models　used　to　fit　the　generated　data　indicated　that　the　provided　combined　pretreatment　had　largely　reduced　standard　blocking　of　the　membrane　pores.　The　effectiveness　of　the　pretreatment　was　confirmed　by　characterization　of　the　hydraulic　irreversible　organic　foulants.　This　work　demonstrated　the　potential　advantages　of　combining　photocatalysis　with　coagulation　as　a　pretreatment　of　raw　surface　water　and　subsequent　UF　in　simultaneously　controlling　membrane　fouling　and　improving　the　permeate　quality.　(c)　2020　Elsevier　Ltd.　All　rights　reserved.