The　porosity　of　Chitosan　Alginate　Fe-sludge　Beads　strengthened　with　manganese　sludge　(CAFBs)　was　optimized　by　adding　CaCO3　or　NaHCO3　powder　to　generate　CO2　gas　during　the　preparation　process.　Two　types　of　adsorbent　Dropped-CAFBs　(D-CAFBs)　and　Heated-CAFBs　(H-CAFBs)　were　made.　SEM-EDS,　BET,　XRD　as　well　as　adsorption　kinetics　and　isothermal　adsorption　experiments　were　used　to　evaluate　the　effects　of　the　two　pore-forming　methods.　The　SEM-EDS,　BET　results　confirmed　that　the　prepared　adsorbent　has　good　porosity　and　specific　surface　area　was　128.16m2/g.　XRD　results　showed　that　the　structure　is　amorphous　iron　manganese　oxide.　The　pseudo-second,　intra-particle　and　Freundlich　model　were　suitable　to　describe　the　adsorption　process(R2＞0.9),　the　maximum　adsorption　capacity　of　As(III)　at　298K　is　24.06mg/g.　The　experiments　indicate　the　pH　ranging　from　9　to　10　and　the　air　aeration　intensity　adjusted　to　1L/min　is　favorable　for　regeneration,　the　percent　of　As(III)　removal　is　as　high　as　about　80%　after　4　adsorption-desorption　cycles.　©　2020　Elsevier　B.V.