Arsenic　(As)　is　among　the　most　dangerous　metalloids　and　is　harmful　to　human　wellbeing.　In　this　laboratory　study,　Al(III)-modified　kapok　fibres　(Al-Kapok)　were　used　to　remove　As(V)　from　water.　The　sorbent　was　characterised　using　Fourier　transform　infrared　spectroscopy　(FT-IR)　and　scanning　electron　microscopy　(SEM)　combined　with　energy-dispersive　X-ray　spectroscopy　(EDX).　Batch　experiments　were　performed　to　observe　the　performance　of　Al-Kapok　in　the　removal　of　As(V)　and　to　examine　the　effects　of　pH,　temperature,　adsorbent　dose,　and　coexisting　ions　on　the　adsorption　process.　The　surface　of　the　sorbent　changed　after　aluminium　modification,　and　the　results　of　the　batch　experiments　showed　that　the　adsorption　of　As(V)　occurred　mainly　via　endothermic-spontaneous　chemisorption　at　the　solution　and　solid　interface　of　Al-Kapok.　The　As(V)　removal　efficiency　was　approximately　76%–84%,　and　it　was　slightly　affected　at　pH　levels　below　8.0.　Further　study　showed　that　the　maximum　adsorption　capacity　of　Al-Kapok　for　As(V)　was　118　μg/g　at　30　°C　and　pH　6,　and　notable　adverse　effects　were　caused　by　the　presence　of　SO42−and　PO43−.　It　was　also　found　that　the　boundary　layer　and　film　diffusion　contributed　more　to　As(V)　adsorption.　After　five　adsorption/desorption　cycles,　regeneration　recovered　approximately　92%　of　the　adsorption　capacity　of　Al-Kapok　used.　Overall,　Al-Kapok　appears　to　be　a　suitable　adsorbent　material　for　the　purification　of　As-contaminated　water.　©　2022　Elsevier　Ltd