The　manganese　sludge　from　laboratory　biological　manganese　removal　filter　column　backwashing　residue　was　used　to　modify　the　Chitosan　Alginate　Fe-sludge　Beads.　The　Chitosan　Alginate　Fe-sludge　Beads　strengthened　with　manganese　sludge　(CAFBs)　get　the　oxidation　ability　and　can　removal　As(III)　effectively　without　a　preoxidation　process.　It　was　characterized　by　SEM　(scanning　electron　microscopy),　XRD　(X-ray　diffraction),　and　BET　(Brunauer-Emmett-Teller　analysis).　Batch　adsorption　experiments　were　carried　out　to　study　the　mechanism　of　As(III)　removal.　SEM-EDS　shows　that　the　surface　is　rough　and　rich　in　iron　and　manganese　element　(32.8%).　The　BET　data　shows　that　it　is　porous　and　has　large　surface　area　(9920　m(2).g(-1)).　XRD　proves　that　the　main　components　of　CAFBs　are　amorphous　iron　oxide　and　MnO2.　Neutral　and　weak　alkaline　conditions　(pH　=　7-9)　were　favorable　for　the　adsorption　and　H2PO4-　had　obvious　inhibitory　effect　on　As(III)　removal.　The　experimental　data　shows　that　the　Pseudo-second　kinetic　model,　intra-granular　diffusion　model　and　Freundlich　isotherm　can　better　describe　the　adsorption　process　of　As(III)　by　CAFBs.　At　298　K,　the　maximum　adsorption　capacity　of　As(III)　is　20.16　mg/g.　Regeneration　studies　find　that　CAFBs　can　be　effectively　regenerated　by　aeration　into　the　NaOH　solution.　(C)　2020　Elsevier　B.V.　All　rights　reserved.