Chemical　cleaning　of　fouled　hollow-fiber　polyvinyl　chloride　(PVC)　membrane　with　the　consecutive　use　of　NaOH　and　ethanol　during　ultrafiltration　of　river　water　was　investigated　in　the　study.　Results　showed　that　through　the　chemical　cleaning　with　1%　NaOH　for　30　min,　a　negative　cleaning　efficiency　of　-14.6%　was　observed　for　the　PVC　membrane.　This　might　be　due　to　the　increase　of　membrane　hydrophobicity,　which　was　reflected　by　the　increase　of　contact　angle　from　69.7　degrees　to　87.6　degrees.　On　the　other　hand,　the　cleaning　efficiency　of　85.1%　was　obtained　by　the　consecutive　cleaning　with　30　min　of　1%　NaOH　and　30　min　of　ethanol.　Individual　ethanol　cleaning　could　remove　48.5%　of　the　irreversible　resistance,　indicating　that　NaOH　cleaning　also　made　its　contribution　(36.6%)　to　the　removal　of　membrane　foulants.　Scanning　electronic　microscopy　(SEM)　and　atomic　force　microscopy　(AFM)　analyses　demonstrated　that　both　NaOH　and　ethanol　were　not　only　able　to　eliminate　the　foulants;　on　membrane　surface,　but　also　able　to　remove　the　in-pore　fouling　of　the　PVC　membrane.　The　synergetic　effects　for　removing　membrane　foulants　were　observed　between　the　NaOH　and　ethanol.　Furthermore,　ethanol　could　also　restore　the　hydrophilicity　of　the　membrane　by　decreasing　the　contact　angle　from　87.6　degrees　to　71.4　degrees.　Considering　that　ethanol　is　easy　to　be　used　and　reclaimed,　the　consecutive　chemical　cleaning　by　alkali　and　ethanol　is　recommended　for　PVC　membrane　in　filtration　of　surface　water.　(C)　2009　Elsevier　Ltd.　All　rights　reserved.